The assessment of physical activity by leisure-time physical activity questionnaires.

Review Article

Spans Medicine 10 (3): 159-180, 1990 0112-1642/90/0009-0159/$11.00/0 © Adis International Limited All rights reserved. SPORT2311

The Assessment of Physical Activity by Leisure-Time Physical Activity Questionnaires K.L. Lamb and D.A. Brodie Department of Movement Science and Physical Education, Faculty of Medicine, University of Liverpool, Liverpool, England

Contents

Sll1!lrnary .................................................................................................................................... 1S9 1. Assessing LTPA by Questionnaire ....................................................................................... 160 2. Leisure-Time Physical Activity Questionnaires .................................................................. 161 2.1 1965 to 1978 .................................................................................................................... 161 2.1 .1 Health Insurance Plan Questionnaire .................................................................. 162 2.1 .2 Tecumseh Questionnaire ............................................................._........................ 162 2.1.3 British Civil Servants Questionnaire .................................................................... 163 2.1.4 Swedish Questionnaire .......................................................................................... 164 2.1.5 Paffenbarger Physical Activity Questionnaire ..................................................... 165 2.1.6 Minnesota Leisure-Time Physical Activity Questionnaire ................................. 166 2.2 1979-1989 ........................................................................................................................ 169 2.2.1 Framingham Physical Activity Questionnaire ..................................................... 169 2.2.2 The Lipid Research Clinics Physical Activity Questionnaire ............................ 170 2.2.3 Bouchard Habitual Physical Activity Questionnaire .......................................... 170 2.2.4 7-Day Physical Activity Questionnaire ................................................................ 171 2.2.5 3-Month Habitual Activity Questionnaire ........................................................... 172 2.2.6 Other Post-1978 Physical Activity Questionnaires ............................................. 173 3. Current Trends ...................................................................................................................... 176 4. Conclusions ............................................................................................................................ 176

Summary

The assessment of physical activity by questionnaire is currently the most popular and practical method of quantifying physical activity levels. Many questionnaires, past and present, have considered overall or habitual physical activity, which includes 0ccupational (or nonleisure) activity. Others have focused specifically on leisure-time physical activity (LTPA) owing to the recognition of1ts dominating contribution to the total physical activity of developed populations. This review covers questionnaires that wholly or in part attend to LTPA levels. Typically, self-complete or interviewer-administered questionnaires record information on the types, frequency and duration of activities performed over a particular period of time. Activity-specific energy cost values, expressed in metabolic equivalents (METS) or kilocalories, are then commonly used to estimate the total energy expenditure from all activities and/or categories of activities. The validation of LTPA questionnaires has had to rely upon indirect methods, such as the assessment of cardiorespiratory fitness, body composition and activity diaries. The

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reporting of the reliability of questionnaires has frequently been ignored, although in cases where it has been reported, doubt exists as to whether the consistency of the questionnaire or the consistency of subjects' physical activity habits were being examined. LTPA questionnaires first appeared in the literature in the mid-1960s for use among specific, mainly middle-aged male population groups. Though they varied in their modes of scoring, periods of activity recall, and overall complexity, associations were universally observed between physical activity levels and chronic health conditions. However, it became apparent that different questionnaires did not yield the same results. In 1978, a questionnaire to assess only LTPA, the Minnesota LTPA Questionnaire, was published and despite its substantial limitations, has since established itself as the most popular option available. In recent years, shorter and simpler alternatives have been advocated, though most have yet to be adequately scrutinised. Associations have been found between LTPA and fitness levels, prompting the use of LTPA questionnaires in large-scale fitness surveys of both adults and children. Although LTPA has continued to be estimated in terms of energy expenditure, little attempt has been made to extend existing knowledge on the energy cost of physical activities. Existing values do not accommodate for individual intensities and inter-population activity variations. Consequently, standardised questionnaires are not yet viable. There exists considerable scope for further work with LTPA questionnaires, especially since the association between cornary heart disease and physical activity is now well recognised. Efforts ought to be directed at wider social groups for whom leisure-time activity may have distinct implications.

For over 3 decades social and physical scientists have sought to assess and monitor human physical activity. Various methods have been employed, including calorimetry (Dauncey et al. 1978), timemotion analysis (Corbin & Pletcher 1968), job classification (Spain & Bradess 1960), diaries (Acheson et al. 1980), doubly labelled water (Schoeller & van Santen 1982), pedometers (Gayle et ai. 1977), electronic motion sensors (Montoye et al. 1983) and dietary assessment (Edholm et al. 1955). Details of these methods can be found in previously published reviews (Montoye & Taylor 1984; laPorte et al. 1985; Wilson et al. 1986). This review will concentrate on currently the most popular and practical method available, the use of physical activity questionnaires. In an appraisal of those questionnaires most widely used up to 1984 (Washburn & Montoye 1986), 6 of 9 described had been designed to assess habitual physical activity, which incorporates both occupational and leisure-time activities. More recently, however, owing to the continued increase in industrial societies of the availability of leisuretime and awareness of the importance of leisure activity in relation to healthy lifestyles, either new

questionnaires have been designed to assess specificially leisure-time physical activity, or established ones have been used more extensively. There are currently at least 38 different questionnaires available (almost all of which are referred to or described in learned journals) that purport in some way to assess LTPA. While it would be tedious to discuss them all, the intention here is to provide primarily an up-to-date critical review of the LTPA questionnaires developed between 1965 and 1989. For each item, discussion will focus on 5 key aspects relating to their use: (a) format and content; (b) time to administer; (c) mode of measurement or scoring; (d) validity and reliability; and (e) popularity. Firstly, however, the reader is provided with a brief overview of this approach to assessing physical activity.

1. Assessing LTPA by Questionnaire Many questionnaires are interviewer-administered, while some, usually the shorter ones, require self-completion. Often, subjects are shown lists of physical activities and are asked to recall which they have taken part in over a specified pe-

Leisure-Time Physical Activity Questionnaires

riod of time (ranging from 2 days to 2 years). In addition, information is usually sought concerning the frequency and duration of each activity reported, thereby enabling the construction of some kind of score or index of LTPA. In most cases, the units of this index have represented an estimate of the amount of energy expended, usually averaged per day, week or month. This has necessitated the use of physiological data obtained from the literature (Edholm et al. 1955; McArdle et al. 1986; Passmore & Durnin 1955) on the energy cost of particular sporting and recreational activities. This can be classified either in kilocalories or multiples of the average resting metabolic rate (METs). On this basis, activities have typically been grouped into distinct categories, such as light, moderate, hard and very hard, defined by selected thresholds. Subjects therefore can be assigned LTPA scores for each category, as well as an overall score. Other activity indices have simply ranked subjects on an ordinal scale, or classified them into one of several summary activity groups. Throughout their history, reliability and validity have been fundamental aspects of physical activity questionnaires. A questionnaire should be capable of obtaining the same information from the same person on 2 separate occasions, and in doing so be measuring actual leisure-time or habitual physical activity. However, reliability and validity have either not always been examined or found to be difficult to establish fully. Since there is no accepted criterion method of assessing physical activity (Baecke et al. 1982; LaPorte et al. 1985), indirect or construct validation has been sought with measures considered to be associated with physical activity. These measures have included body composition, physical fitness, physical activity diaries and energy (dietary) intake. To examine reliability, a test-retest procedure is traditionally the optimal method. However, unless a retest occurs within a short time after the initial test, say after a few hours or at most 1 or 2 days, then depending upon the time span of a particular questionnaire, it may be that it is actually the subject's reliability that is being examined. For example, a questionnaire that requires a recall of all

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activities participated in over the last 12 months (Taylor et al. 1978) should not be greatly affected by a retest occurring days or even several weeks after an initial test. In this case, the repeatability of the questionnaire is indeed being examined. If the period of activity recall is only 7 days (Sallis et al. 1985), however, then a similar retest delay may be affected by memory (if the subject is asked to recall activities from the same period as before) or the stability of the subject's physical activity habits. Many studies have either failed to account for these factors or clarify their reliability method. Finally, one might have expected that the reliability of an LTPA questionnaire would influence attempts to further validate it or make use of it in the manner for which it was originally intended. Surprisingly, however, the most popular LTPA questionnaires, for example, the Minnesota LTPA Questionnaire (Taylor et al. 1978) and the Paffenbarger Physical Activity Questionnaire (Paffenbarger et al. 1978), were not reported to be reliable until several years after their original publication.

2. Leisure-Time Physical Activity

Questionnaires 2.1 1965 to 1978 The earliest reported questionnaires for assessing LTPA were by Wessel et al. (1965) and Shapiro et al. (1965), both of which also examined occupational physical activity. The questionnaire by Wessel, later to be modified into the Tecumseh Questionnaire (Reiff et al. 1967), was originally intended to be self-administered and capable of classifying a population into physical activity subgroups (light, moderate, active and very active). A random sample of 100 males and 100 females provided responses to questions about the kind and frequency of participation in physical activities over the preceding year. Information regarding the completion time and the reliability of the questionnaire was not reported. In order to determine the accuracy of these responses, however, a follow-up personal interview was conducted with each subject. Three judges independently appraised the self- and interviewer-administered questionnaires and classified

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subjects into the 4 physical activity groups. In addition, they collectively used both questionnaires to determine the best (or 'criterion') classification for each subject. An objective classification was also devised that made use of activity energy expenditure values (Passmore & Durnin 1955). Activities with similar expenditure values were grouped as follows: 0.5 to 1 kcaljmin (light); 1 to 1.5 kcaljmin (moderately active); 1.5 to 2 kcaljmin (active); 2.0 to 5 kcaljmin (very active). Respondents were assigned a score for each group, based on the number and frequency of activities reported. While the subjective ratings of the judges for both questionnaires proved to be consistent, the classification of subjects using the self-administered questionnaire differed markedly from that using the interview questionnaire and criterion method. A similar finding was obtained between the objective and criterion classifications. It was concluded that the validity of the self-administered questionnaire was not satisfactory, but combined with an interview, a reasonably accurate method of classifying subjects into physical activity subgroups could be developed.

of physical activity and early mortality following initial myocardial infarction. Mortality was found to be 3 times greater in the 'least active' group than the 'most active' grouPl Cassel et a1. (1971) reported a decreased prevalence of coronary heart disease (CHD) with increasing LTPA among 2530 males aged 40 to 74 years, although this was observed only for those also with a high work-time physical activity level. This study used a modified HIP questionnaire in which leisure-time activities more appropriate to a rural community, such as hunting or fishing, were assessed. On the same theme, Hennekens et al. (1977) showed a significantly (p < 0.001) reduced risk of coronary death with increasing LTPA among 568 males aged 30 to 70 years. Buskirk et al. (1971) compared the HIP LTPA ratings of 198 middle-aged males with those obtained from the Tecumseh Questionnaire and observed a correlation of only r = 0.29 (level of significance not reported). Such a finding emphasises the variability that can exist between methods of assessing LTPA.

2.1.1 Health Insurance Plan Questionnaire

The Tecumseh Questionnaire, referred to above, was established for use in a community health study by Reiff et al. (1967), although initially it was a revised version of Wessel and colleagues' (1965) questionnaire-interview schedule that was tested on a subsample of 184 males aged 16 years and above. After completing a self-administered questionnaire (enquiring via a 99-item check-list about occupational, leisure-time, sports, gardening and other physical activities during the preceding year), subjects later received an in-depth home interview, lasting from half to 1 hour. The interview enquired about the frequency and duration (in hours) for each physical activity reported. An LTPA index was calculated as the average daily number of METs expended during the year in leisure activities. (As briefly mentioned earlier, many physical activities can be assigned a MET value, representing the metabolic or energy cost to an individual, regardless of bodyweight.) Alternatively, this Activity Metabolic Index (AMI) was transformed into units

The Health Insurance Plan (HIP) Questionnaire, first reported by Shapiro et a1. (1965), was a short, 2-part instrument covering both occupation and leisure-time physical activity. The LTPA part required responses to just 5 questions asking about the frequency of participation (frequently/sometimes/very infrequently/never) in walks, housework, gardening and sports. Each activity carried a weighting factor that varied according to the frequency category. Male subjects aged over 30 were classified (1 to 4) on the basis of their accumulated weights, which ranged from 0 to 10. This simple, self-administered questionnaire took less than 10 minutes to complete and therefore appeared to be suitable for large-scale use. However, its reliability has not been reported and studies of its validity have been few. Using the complete HIP among 301 males (aged 25 to 64 years), Frank et a1. (1966) reported a significant relationship (p < 0.01) between overall level

2.1.2 Tecumseh Questionnaire

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of caloric expenditure (kcalfday) by adopting 1 MET as being equal to 1 kcalfmin. Although the reliability of the Tecumseh Questionnaire has not been reported, an early attempt at validation was provided by Skinner et al. (1966), who examined its association with a measure of cardiorespiratory fitness. Among 54 males (aged 40 to 59 years) who had been respondents in a largescale morbidity survey, daily overall AMI (including occupational activity) and performance in a submaximal treadmill test had a nonsignificant correlation ofr = 0.13. Likewise, Buskirk et al. (1971) found a low, nonsignificant correlation (r = -0.10) between overall AMI and daily caloric intake among 198 males aged 40 to 59 years. However, when caloric intake was divided by bodyweight and the overall levels of physical activity of 1300 men aged 16 to 65 years were reclassified as 'active' (highest 20%), 'moderately active' (middle 60%) or 'sedentary' (lowest 20%) and controlled for age group, active subjects were found to consume significantly (p < 0.01) more calories than sedentary subjects (Montoye et al. 1976). Other, more indirect, sources of validation have been reported with data obtained from the same Tecumseh population (n = 9500) by Montoye and colleagues. These studies have observed that some active subjects had significantly (p < 0.05) more favourable physiological characteristics, for example, a better glucose tolerance among the leanest 33% (Montoye et al. 1977), a lower blood pressure (Montoye et al. 1972), lower body fatness (Montoye et al. 1976), and lower serum uric acid (Montoye et al. 1967) than less active subjects. Montoye et al. (1976) also reported an inverse relationship between physical activity and serum lipid levels (p < 0.05), although for most age groups when body fatness was accounted for, the relationship did not exist. The Tecumseh Questionnaire has been shown to be capable of achieving that for which it was intended, that is, categorising individuals in terms oftheir physical activity, in order then to examine the independent role of physical activity in explaining the health status and health risks of a whole community. However, the questionnaire has not been used elsewhere since the Tecumseh study. The

reason for this may be rooted in the change of research emphasis that occurred in the 1970s, at which time there was a shift to concentrating on just leisure-time physical activity. This led to the development of its successor, the Minnesota LTPA Questionnaire (Taylor et al. 1978). The first LTPAonly questionnaire, however, was developed and used for a major prospective study of CHD among middle-aged male British civil servants (Alderson & Yasin 1966; Yasin et al. 1967).

2.1.3 British Civil Servants Questionnaire During its initial testing, the British Civil Servants (BCS) Questionnaire was interviewer-administered and took about 1 hour to obtain a complete 2-day leisure-time activity recall (Alderson & Yasin 1966). 117 male executive-grade officers (aged 40 to 54 years), classified in their occupation as sedentary, were interviewed 4 times over a 14month period. They recalled the length of every activity lasting 5 minutes or longer performed out of work during the 2 preceding days. Eight days of LTPA (4 weekdays and 4 weekend days) were thus described. Based on published values of oxygen consumption for different activities, each activity was assigned to one of 5 categories: sedentary, light, moderate, strenuous and sport. Activity categories were allocated a score from 1 to 5 (sedentary to sport) and each activity reported was scored for each 5-minute period it was performed. An hour of tennis therefore scored 60 points (12 x 5) and 30 minutes of watching television scored 6 points (6 x 1). The sum of each 5-minute period of leisure-time activity yielded an average daily activity score, which ranged from 217 to 399 (mean = 300) points. By dividing the sample into thirds (redefined as inactive, middle active and active groups) there was a mean difference of 79 points between the most active and least active groups. The reliability of the procedure was described in terms of the stability of individual scores; a correlation of 0.67 was reported between the weekend days (Saturday or Sunday) and the total 8-day score, and a correlation of 0.55 between the work-day and weekend day scores (Alderson & Yasin 1966). Indirect validation was sought with a I-week weighed

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dietary survey, aimed at estimating energy intake, and skinfold measurements (Yasin et al. 1967). Among 32 participating subjects, those classified as active on the 8-day activity record had an average energy intake of 150 kcal/day more than those classified as inactive. However, the correlation of 0.27 between activity scores and energy intake was not significant (p > 0.05). Active subjects were found to have thinner skinfolds than inactive subjects and a negative association between activity level and skinfolds (r = -0.31) was significant (p < 0.05). Although the pilot study group proved the interview procedure to be only reasonably reliable and valid, a self-administered questionnaire version was subsequently used between 1968 and 1970 among 16 882 males aged 40 to 64 in the BCS study. Having used 2-day leisure-time activity records (for Friday and Saturday), Morris et al. (1973) discovered that for respondents recording vigorous LTPA (defined as activity requiring peaks of energy output of 7.5 kcal/min or greater) the relative risk of developing CHD was approximately 33% of that in comparable respondents who did not report vigorous LTPA. Epstein et al. (1976) showed that among a subsample of the British civil servants (n = 509) those who had reported taking part in vigorous LTPA had significantly fewer (p < 0.02) electrocardiographic abnormalities than those who had not reported vigourous LTPA. The apparent beneficial effect of vigorous LTPA was further supported after the end of the study by Chave et al. (1978) who reported that deaths from CHD and all causes were significantly fewer (p < 0.001) among males reporting vigorous LTPA than among males reporting no such LTPA. As with the Tecumseh Questionnaire, the BCS Questionnaire has not been used outside the population for which it was designed. It has been argued that the BCS procedure is very time-consuming and may be too demanding for all but the most motivated and educated people, who are better able to provide valid and reliable information than the general population (Washburn & Montoye 1986). Furthermore, the short time-frame studies may not represent an individual's typical LTPA pattern.


Undoubtedly, however, the findings from the survey of British civil servants have stimulated further advancements in the assessment of leisure-time physical activity and the study of its associations with health.

2.1.4 Swedish Questionnaire Developed in Sweden by Saltin and Grimby (1968) for use in a study of former trained athletes, a simple physical activity questionnaire proved to be a versatile alternative to those already described. This brief, self-administered instrument required respondents to classifY themselves into one of 4 activity groups for both occupational and leisure-time activities. For leisure-time activities, placement in group 1 reflected being almost completely inactive, while group 4 reflected regular hard physical training. Respondents indicated the group applicable to them for at least 7 months per year and the group applicable for between 2 and 6 months per year. In addition to the previous year, the questionnaire was also used to provide an estimate of LTPA for the previous 4 years and 10year intervals from age 20 to 50 years. It was used initially among a representative sample of male respondents in a primary preventive trial (n = 8300) in Gothenburg (Wilhelmsen et al. 1972). At no time, however, has the reliability of the questionnaire been reported. Indirect validity was established among a subsample of the Gothenburg population (n = 803) in which the average predicted maximal oxygen uptake (V02max) of those classified in the 2 most active LTPA groups (based on the preceding year) was significantly higher (p < 0.005) than those in the 2 least active groups (Grimby et al. 1971). Lindgarde and Salt1n (1981), in a study of 115 normoglycaemic males aged 47 to 49, found also that those who reported some LTPA (groups 2 and above) had, on average, higher V02max and lower glucose and insulin (measured by an oral glucose tolerance test) than those who reported no LTPA (p < 0.05). Wilhelmsen et al. (1976) showed that LTPA during the previous year was related to the incidence of CHD during the following 8 years (p < 0.05).


The Swedish questionnaire was adopted as the measure of LTPA for subsequent large-scale longitudinal studies of CHD in Scandinavia (Punsar & Karvonen 1976; Salonen et al. 1981). Salonen et al. (1982) reported that among a random Finnish population of 3978 males aged 30 to 59 years and 3688 females aged 35 to 59, low LTPA during the preceding year was associated with an increased risk of death (p < 0.01). Among the females only, those categorised as having low LTPA had a significantly higher (p < 0.001) mean body mass index. Repeated administration of the questionnaire over a lO-year period enabled trends in the LTPA of this population to be monitored (Marti et al. 1988). A significant increase in the proportion of those classified as highly active (activity groups 2 to 4) was a pertinent feature of this analysis (p < 0.001). Cederholm and Wibell (1986) have reported from a Swedish urban population of 436 females and 371 males (aged 47 to 54 years) that mean systolic and diastolic blood pressures and the frequency of hypertensives were significantly lower (p < 0.05) among those with high LTPA (activity groups 3 and 4) than those with low LTPA (activity groups 1 and 2). In a 1977 study of cardiovascular disease in Finnmark, northern Norway (TheIle et al. 1982), LTPA was assessed among 7338 males and 6768 females aged 20 to 53 years by the Swedish questionnaire. LTPA, represented by the 4 activity groups, was found to have a weak, but significant (p not reported) positive association with high density lipoprotein (HDL) cholesterol (Forde et al. 1986). The Swedish questionnaire has proved to be a valid and popular measure ofLTPA in its place of origin. Its brevity and self-complete format are assets where large, longitudinal studies are concerned and it has been shown to be capable of demonstrating changes in LTPA over time. However, its broad activity categories (often dichotomised into active/inactive or high/low groups) reduce the questionnaire's overall sensitivity.

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2.1.5 Paffenbarger Physical Activity Questionnaire A slightly more demanding physical activity questionnaire was developed and initially used by Paffenbarger et al. (1978) in a longitudinal study of physical activity and heart attack risk among 16936 male Harvard University alumni. The 1page self-administered questionnaire asked respondents to recall how many flights of stairs they climbed each day (10 steps equalled 1 flight), how many city blocks (12 blocks equalled lkm) walked each day and what sports they actively played (in hours) each week. In addition, the questionnaire asked the number of times a subject sweated per week through physical activity. For analysis purposes, 1 flight of stairs per day was equated to 28 kcal/week energy expenditure and 1 block per day equated to 56 kcal/week. Each sport reported was assigned an energy expenditure value (kcal/week) from the now popular standard values obtained from the literature. Alternatively, they were reclassified as light « 5 kcal/min) or strenuous (> 10 kcal/min). An overall index of physical activity, expressed in kcal/week, was calculated as the composite estimate of energy expenditure from the 3 sections of the questionnaire. Although work-time physical activity was not particularly covered, the questionnaire did include activities that might be performed during the working day (e.g. climbing flights of stairs). Furthermore, the questionnaire was designed for use with a specific population, for whom occupational activity was likely to be on the whole sedentary. In effect, therefore, physical activities of an intensity above that required by normal daily activities (which includes many leisure activities) were recorded with this questionnaire. Its reliability was initially examined among a small sample of the Harvard population (n = 410) by comparing the self-administered reports with those obtained via a telephone interview. Paffenbarger and his colleagues reported that there were no significant differences between the 2 responses. Five years later, LaPorte et al. (1983) examined the test-retest reliability of this instrument among 59 postmenopausal females aged 45 to 74 years. It was found

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that 1 year apart, correlation coefficients for total weekly energy expenditure, blocks walked, flights ofstairs climbed and sweat episodes were r = 0.73, 0.42,0.54 and 0.46 (p < 0.001), respectively. However, arguably the stability of the subjects' activity was measured here and not the questionnaire's repeatability. Short term reliability was examined by Cauley et al. (1987) as part of a small pilot study involving 14 postmenopausal women (mean age 59.1 years). Four-week test-retest coefficients were superior to those over 1 year: r = 0.76 (p < 0.001), r = 0.97 (p < 0.002), and r = 0.89 (p < 0.001) for total energy expenditure, blocks walked and flights of stairs climbed, respectively. The same authors also examined the validity of the questionnaire in a larger study of postmenopausal women (n = 255) by comparing it with an estimate of energy intake, derived from a 3-day dietary survey, and the output of a Large-Scale Integrated Activity Monitor (LSI) [LaPorte et al. 1979]. Among those women assigned to an intervention group [involving walking 7 to 9 miles (11 to 14.5km) per week] a modest correlation of r = 0.33 (p < 0.01) was found between total activity registered by the LSI and total energy expenditure assessed by the Paffenbarger questionnaire. A low, nonsignificant correlation was found between energy intake and the questionnaire index (r = 0.02; p > 0.05). Among those women assigned to the control group (n = 125), the correlation between the LSI and the Paffenbarger index was lower (r = 0.17; P < 0.05). Recently, Kriska et al. (1988) have reported moderate correlations between both the overall activity index and the sports index, and an index assessing periods of historical LTPA (for both, r = 0.41; p < 0.001). Siconolfi et al. (1985) reported a significant association between the activity index and V02max (r = 0.29; p < 0.05) among a group of 36 males and 32 females, although not for the males and females separately. This lack of a significant association was attributed to the small range of maximal oxygen uptake values found in each gender group. Interestingly, moderate correlations were observed between the frequency of


sweating and maximal oxygen uptake for the whole group and males only; r = 0.46 and 0.54 (p < 0.01), respectively. From the original investigation of Harvard alumni (Paffenbarger et al. 1978), it was reported that the relative risk of first heart attack was significantly less (p < 0.001) for both those with a physical activity index greater than 2000 keal/week and those engaged in strenuous sports. Paffenbarger et al. (1983) later reported that alumni falling into the same categories (Le. having an activity index greater than 2000 kcal/week and engaged in strenuous sports) had a 35 and 30%, respectively, lower risk of developing hypertension (p < 0.005). Also, among the postmenopausal females referred to above (n = 74), it has been reported that those expending 2000 or more keal/week had significantly (p < 0.04) higher and thereby more favourable levels of HDL cholesterol (Cauley et al. 1982). Total weekly physieal activity and strenuous activity were independently correlated with HDL cholesterol; r = 0.25 and 0.27 (p < 0.01), respectively. However, a study of a larger group of such women (n = 256) revealed a correlation of only r = 0.15 (p < 0.05) between HDL cholesterol and the activity index (Cauley et al. 1984). The Paffenbarger Physical Activity Questionnaire was designed to assess participation in physical activities more intense than so-called 'normal' daily activities. Its current format would render certain aspects of it (such as walking blocks or up stairs) redundant among many populations, leaving an index of energy expended in sports. Nevertheless, it has demonstrated a degree of reliability and validity and has yielded associations with health variables. Although its use so far has been limited to only a few studies, the questionnaire's relative simplicity may have a substantial bearing on its future use in large-scale surveys, particularly if it can be adapted for specific populations. 2.1.6 Minnesota Leisure-Time Physical Activity Questionnaire Published in 1978 by Taylor et al. (1978), the Minnesota Leisure-Time Physieal Activity Questionnaire (MLTPAQ) has established itself as the


most popular physical activity questionnaire, having been used in at least 18 published studies. It was developed as a shortened version of the Tecumseh Questionnaire and designed to obtain information about participation in leisure-time activities only. Subjects indicate on a check-list which activities (including nonsporting activities) they have performed during the past year. An interviewer then spends an average of 20 minutes per person obtaining detailed information about the number of months each activity was performed, the frequency in each month and the average duration of each occasion. As with the Tecumseh Questionnaire, overall energy expenditure is expressed (in kcal/min) as an Activity Metabolic Index (AMI), calculated with intensity codes obtained from the literature. Separate indices can be calculated to define light « 4 kcal/min), moderate (4 to 5.9 kcal/min) and heavy (~ 6 kcal/min) activities. Worthy of mention here are the limitations of working with intensity codes, as noted by Taylor and his colleagues. Firstly, the use of a basal (resting)-to-work metabolic rate for the calculation of intensity codes is not exact, since basal metabolism is not consistent at 1 kcal/min, as often interpreted. Secondly, individual variation in the vigour of performing activities can have a marked effect on the actual energy expended, and therefore the intensity code value. Thirdly, some activities do not have intensity codes, making estimations necessary. In populations where many such activities are regularly performed, the scope for error is thereby enhanced. The Minnesota LTPA Questionnaire was adapted originally to test the hypothesis that exercise sufficient to produce a cardiovascular conditioning (training) effect serves as a direct or indirect mechanism of protection against CHD. The threshold for heavy activity (6 kcal/min) was regarded as the minimal intensity of effort required to stimulate such a training effect (approximately 60% OfV02max). Initial validation of the MLTPAQ among a sample of 175 males aged 36 to 59 sought to establish a significant association between participation in heavy physical activities and aerobic

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capacity. Leon et al. (1981) reported significant correlations (p < 0.001) between exercise duration in a graded treadmill test and total LTPA (r =0.41) and heavy LTPA (r = 0.44) for this study sample. Furthermore, multiple regression analysis with other health-related variables revealed that heavy LTPA had a multiple correlation coeffiicient of r = 0.44. By squaring this value to give the coefficient of determination (r2), heavy LTPA was found to account for the most variance in treadmill duration (19.4%). In a prospective study of physical activity, physical fitness and cardiovascular diseases among a population of 3179 Belgian males aged 40 to 59 years (Sobolski et al. 1981), an identical validation to that above was undertaken. This time, however, exercise duration was found to have a low association with total LTPA (r = 0.08; p < 0.05) and heavy LTPA (r = 0.11; p < 0.001) [DeBacker et al. 1981]. The same analysis was reported for a parallel study of 2381 male Slovaks (Sobolski et a1. 1988) and equally low correlations between LTPA and cardiorespiratory fitness were found; r = 0.10 and 0.09 for total and heavy LTPA, respectively (p < 0.001). The authors suggested that the relatively sedentary lifestyles of the Belgian and Slovakian males (with 34 and 51 %, respectively), having not recalled any heavy activity during ~the past year) and small range of cardiorespiratory fitness, were the likely causes of the low correlations obtained. Interrelationships between measures of cardiorespiratory fitness (resting and submaximal exercise heart rates) and physical activity have recently been reported among 2356 healthy male employees of United States railroad companies in 1957 to 1960 (Slattery & Jacobs 1987). The LTPA questionnaire used was described as being the 'precursor to the Minnesota LTPA' and was deemed to be similar 'in the detail obtained about leisure-time activities as well as in methods for coding'. Total LTPA was found to be related to resting pulse (p < 0.05) and exercise heart rate (p < 0.01), as was heavy LTPA (p < 0.01). In addition, a positive relationship was also reported between dietary intake (obtained from a 24-hour recall) and total and heavy LTPA (p < 0.01). In a larger study of 12866 males (aged 35

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to 57) considered to be at high risk of CHD, exercise duration in a submaximal, progressive treadmill test was found to be positively related (p < 0.01) to minutes per day of LTPA (Crow et al. 1986). Validation against an 'objective' measure of physical activity, the Large-Scale Integrated Activity Monitor (LSI), was attempted by LaPorte et al. (1979) among 20 male undergraduates. The LSI device is designed to represent physical activity by monitoring and counting body movements. When located on the waist (to monitor trunk movement), activity measured by the MLTPAQ and the LSI had a correlation ofr = 0.69 (p < 0.01); when attached to the ankle (to monitor leg movement), the correlation was lower and nonsignificant (r = 0.43; p > 0.05). A later study among a small number of boys (n = 8) aged 12 to 14 years (LaPorte et al. 1982) compared results from the MLTPAQ with 2-day readings of an LSI and a 3-day dietary intake record. Neither the LSI readings nor the dietary records were significantly correlated with the MLTPAQ. In addition, LTPA was not significantly related to a variety of health-related fitness measures, including "02max, flexibility, muscular endurance and body composition. An obvious inconsistency with such comparisons is the time-span of monitoring; 2 or 3 days may not adequately reflect movement or dietary patterns, whereas a I-year period (MLTPAQ) probably reflects physical activity patterns well. Also, maturation differences among the children may have affected their fitness scores. In the same report, LSI activity and LTPA assessed during nonworking days among 42 middle-aged males were found to be positively correlated (r = 0.45; p < 0.05), though no corrrelation was found between the MLTPAQ and LSI activity during 2 working days. The reliability of the MLTPAQ was not reported until 1986, when Folsom et al. (1986) examined its test-retest reliability over 5 weeks among 140 respondents (males and females aged 25 to 74) in a community health programme, and over 2 weeks among 150 males (aged 41 to 64) at high risk ofCHD. For the 140 males and females, Spearman rank-order correlations between the 2 measure-


ments were high; r = 0.88, 0.79, 0.86 and 0.82 (p < 0.001) for total, light, moderate and heavy LTPA scores, respectively. Slightly lower test-retest correlations were observed among the 150 male subjects; r = 0.79, 0.82, 0.73, and 0.69 for total, light, moderate and heavy LTPA scores, respectively. The most active subjects (those with the greater reported energy expenditure) had the larger test-retest differences. The authors attributed this to persons with greater activity levels often participating in some activities very frequently, and even slight error in recall of the duration of these activities will lead to disparate test-retest scores. Reports examining the relationships between LTPA as assessed by the Minnesota questionnaire and health aspects, in particular disease and illness, continue to appear in the literature. Very recently, Marcoux et al. (1989) reported that women who performed regular LTPA during the first 20 weeks of pregnancy had a reduced risk of pre-eclampsia and gestational hypertension, which decreased further as the average time spent in LTPA increased. In the Minnesota Heart Survey of 3448 adults aged 25 to 74 years (Folsom et al. 1985), daily total and heavy LTPA energy expenditure were found to be significantly associated with HDL cholesterol (p < 0.05). Risk factors of CHD were also found to be related (p < 0.01) to LTPA levels in a study of 1598 males and 1762 females (aged 20 to 69 years) reported by Dannenberg et al. (1989). Lower total and higher HDL cholesterol, lower body mass index, lower resting heart rate and fewer cigarettes smoked were observed with increasing physical activity (kcal/year). Siscovick et al. (1982) observed a reduced risk of primary cardiac arrest with increasing high intensity (heavy) LTPA (p < 0.001) among males aged 25 to 75 years. Similarly, in a report by Leon et al. (1987) the incidence of CHD among 12 138 high risk, middle-aged males was found to be 20% lower (p < 0.05) for respondents reporting the highest LTPA (top 33%) than those reporting the lowest LTPA (bottom 33%). Over the past 11 years the Minnesota questionnaire has established itself in North America as the primary recall procedure for assessing levels of LTPA and their relationships with health-related

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factors. Although time-consuming (and thereby not ideal for large surveys) and reliant on recall spanning a whole year, the questionnaire continues to be used and advocated as one of the best options for future research (Wilson et al. 1986). Apart from providing a good general measure ofLTPA, a pertinent reason for its popularity is its ability to distinguish between activity intensity levels. As highlighted above, this factor has been shown to have considerable relevance in the assessment and monitoring of health. Several other habitual or LTPA questionnaires were reported between 1965 and 1978 (e.g. Cullen & Weeks 1978; Goldsmith & Hale 1971; Gyntelberg 1973; McDonough et al. 1970), but apparently were not adopted for use in studies other than that of their origin.

2.2 1979 to 1989

Since 1978, many physical activity questionnaires have focussed solely on leisure-time activity. Several have continued to assess LTPA as the amount of energy expended, overall and in specific categories, over a given period of time (Bouchard et al. 1983; P~rker et al. 1988; Sallis et al. 1985; Verschuur & Kemper 1985). This still requires the use of energy cost values obtained mainly from studies reported in the 1950s. Since little work has been reported in recent years that either confirms or extends our knowledge of the energy cost of physical activities, the limitations of this method have remained. Alternative and often simpler questionnaires have therefore been developed, particularly when a detailed account ofLTPA was not deemed necessary (Godin & Shephard 1985; Haskell et al. 1980; Mundal et al. 1987). While many of the most recent ones await validation, confirmation of reliability and widespread application, there has remained much interest in the development of LTPA questionnaires, primarily owing to the growing evidence of importance of lifestyle in preventive medicine.

2.2.1 Framingham Physical Activity Questionnaire Developed for use in a longitudinal study of the incidence of CHD, the Framingham Physical Activity Questionnaire was designed to assess habitual activity. The interviewer-administered procedure (Kannel & Sorlie 1979) required subjects to report the usual number of hours spent each day at rest (including sleep), in work and in extracurricular activities. Five activity categories were defined on the basis of oxygen consumption values and weighted accordingly: basal (1.0), sedentary (l.l), slight (1.5), moderate (2.4) and heavy (5.0). It is not clear from the literature how long the interview took, whether subjects reported the actual activities (to be later assigned to an activity category) or how 'usual activity' was defined. A physical activity index (PAl) was calculated as the sum of the hours spent in each weighted activity category. Scores could therefore range from 24 (24 hours of basal activity) to 120 (24 hours of heavy activity). The repeatability of the physical activity assessment was reported to have been represented by 3 successive examinations, 2.5 to 3 years apart (Garcia-Palmieri et al. 1982). With such a timespan, it is hardly surprising that correlations were low (r = 0.30 to 0.59), indicating that marked changes in physical activity levels had occurred. Validation of the questionnaire has been reported through associations of physical activity with health-related factors. Garcia-Palmieri et al. (1982) found low order negative correlations (significance levels not reported) between the PAl and resting heart rate, blood pressure, relative bodyweight and serum cholesterol among 8793 male respondents (aged 45 to 64 years) in the Puerto Rico Heart Health Study. The same report observed an inverse association between physical activity and the 8.25 years incidence of CHD; the highest incidence found was among those representing the lowest activity group (PAl = 24 to 29). Data from the Framingham Study (Kannel & Sorlie 1979) involving 1909 males and 2311 females (aged 35 to 69 years) revealed a relationship between physical activity and mortality caused by

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CHD, though this was not significant (p not reported) among females when adjusted for age. In the Honolulu Heart Program, a prospective investigation ofCHD among 7705 Japanese males (aged 45 to 68 years) living in Hawaii, the PAl was found to be a significant predictor (p < 0.05) of total CHD after 10 years offollow-up (Yano et al. 1984). Limited validity and poor reported reliability, along with the uncertainty surrounding its content and administration, make the Framingham questionnaire instinctively unattractive in comparison with others already described. In addition, its method of assessing physical activity lacks specificity and therefore would seem to be open to considerable overgeneralisation.

2.2.2 The Lipid Research Clinics Physical Activity Questionnaire A short, 2-question procedure was formed for use in a international survey of the lipoprotein determinants of 2319 males and 2067 females aged 20 to 70 years (Haskell et al. 1980). Respondents were asked, 'Do you regularly engage in strenuous exercise or hard physical labour?' If the answer was positive, respondents were then asked 'Do you labour or exercise strenuously at least three times a week?' Respondents answering positively to both questions were considered to be very active, while those answering negatively to the first question were considered to be inactive. Those answering negatively to the second question were considered to be moderately active. Thus, a broad classification of strenuous habitual physical activity, intended to help establish target heart rates for a subsequent submaximal treadmill exercise test, was obtained. The reliability of this questionnaire has not been reported, though its simplicity implies that readministration within a reasonable period of time oUght to produce identical results. Indirect validation was provided by Haskell et al. (1980) who reported that at all ages, very active and moderately active males and females had longer exercise durations and lower resting and exercising heart rates (significance not reported) than inactive males and females. Results from the same study showed that in some age groups (males, 30 to 39, 40 to 49;


females, 20 to 29, 30 to 39) participation in strenuous physical activity was significantly related (p < 0.05) to HDL cholesterol levels. Recently, Siscovick et al. (1988) have studied physical activity and CHD among 1533 hypercholesterolaemic (total cholesterol> 6.85 mmol/L) males aged 35 to 59 years. This study confirmed the above relationships between physical activity and exercise tolerance and resting and exercise heart rates, though significance levels were again not reported. No relationship was found, however, between physical activity and the incidence of fatal or nonfatal CHD after 7.4 years follow-up. The Lipid Research Clinics Physical Activity Questionnaire is an example of a limited-use item, designed for a specific purpose. It is brief, undemanding and appears to be a valid measure of strenuous physical activity.

2.2.3 Bouchard Habitual Physical Activity Questionnaire In contrast to the above questionnaire, the procedure used by Bouchard et al. (1983) among 150 children and 150 adults (aged 10 to 50 years) required a detailed account of 3 days' (2 weekdays, 1 weekend day) physical activity, broken down by IS-minute intervals. Activities were qualified on a scale of 1 to 9 using published values for energy costs of specific activities. For each category, approximate median energy cost in kcal/kgf 15 min was used to compute daily energy expenditure. A 6- to lO-day test-retest of 61 of the adults and children revealed the questionnaire to be highly repeatable, although it was not clear whether the same 3 days were recalled on both occasions. Reliability correlations of r = 0.96, 0.91 and 0.97 (p < 0.01) were obtained for the mean 3-day energy expenditure of the whole sample, children and adults, respectively. The highest intensity category (2 kcal/ kg/IS min) was most reliably repeated (r = 0.88; p < 0.01). Bouchard and his colleagues indirectly validated their questionnaire against a submaximal, cycle ergometer measure of physical work capacity (PWC) and percentage body fat. Correlation coefficients for the whole sample were r = 0.31 and


0.32 (p < 0.05) between PWC (relative to bodyweight) and mean daily energy expenditure and the highest intensity category, respectively. Percentage body fat was also associated with daily energy expenditure (r = -0.13; p < 0.05). Following its initial testing, the 3-day recall questionnaire was finally administered to a total of 1610 subjects (717 adults, 893 children), representing 375 families in Quebec, Canada. The respondents were volunteers in a study of the genetic and environmental determinants of physical activity level. Among this population, it was reported that level of habitual physical activity (adjusted for age, sex, PWC, obesity and socioeconomic status) was significantly influenced (p < 0.05) by genetic factors (Perusse et al. 1989). Also, participation in activities of 5 METs or greater was found to be significantly influenced (p < 0.05) by cultural inheritance. Though not as detailed as the British Civil Servants Questionnaire, the Bouchard questionnaire seems to be as equally demanding and susceptible to the reporting of atypical physical activities. Its limited use probably reflects this. Nevertheless, its high reliability and comparatively good validity reinforces the acceptability of this type of recall questionnaire. 2.2.4 7-Day Physical Activity Questionnaire An interviewer-administered 7-day recall ofleisure and occupational physical activities was developed for a 5-city community-based health education programme, in California in 1979 and 1980 (Sallis et al. 1985). In essence, this procedure proved to be a shorter (lasting less than 20 minutes), less general successor to the Minnesota LTPA Questionnaire previously described. A random sample of2126 people (1006 males, 1120 females) aged 20 to 74 years were asked to recall the time spent during the past 7 days in activities displayed to them on 3 lists. These lists covered activities categorised as 'moderate' (3.0 to 5.0 METs), 'hard' (5.1 to 6.9 METs) and 'very hard' (~ 7.0 METs). Time spent in light activities (1.0 to 2.9 METs) was later obtained by subtraction. In practice, therefore, since most of a day was spent either sleeping (1 MET)

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or in light activities, subjects were required to account in detail for less than 5 hours of activity. Mean MET values for each category were used to calculate energy expenditure in kcal/day or kcal/ kg/day. The sum of each category yielded a total physical activity index. A 2-week test-retest reliability study was conducted among a self-selected sample of 58 of the study's subjects. (It is assumed that the same 7-day period was not re-examined at the second interview, and that the stability of the subjects' physical activity was being assessed.) Correlation coefficients for the number of hours spent in each intensity category ranged from r = 0.08 (p > 0.50) for moderate activities to r = 0.61 (p < 0.0001) for very hard activities. Total energy expenditure in kcal/day was not significantly different over the 2 weeks and had a reliability correlation ofr = 0.67. Validation of the 7-day recall was provided initially by Taylor et al. (1984) who compared it to a daily self-report log of physical activity and a solid-state activity monitor, among a sample of 30 male subjects (aged 34 to 69 years) in a cardiac rehabilitation programme. Total daily hours of energy expenditure were well correlated between the 7-day recall and self-report log methods (r = 0.81; p < 0.01), though correlations varied for specific activity categories on different days (r = 0.42 to 0.90). Mean daily energy expenditure recorded by the 3 methods was not significantly different. Additional validation has been reported simultaneously from 4 studies in which the 7-day recall, or rather a simplified version of it, was used (Blair et al. 1985). Firstly, among a subsample of the community health programme mentioned above (495 males, 545 females), recall energy expenditure was found to have a positive association with energy intake estimates obtained from a 24-hour dietary recall (r = 0.16, p < 0.001 for males; r = 0.09, p < 0.05 for females). Secondly, the sensitivity of the 7-day recall was verified in an exercise-training study, involving 81 initially sedentary males. Following a year's programme of training, the recall confirmed that exercisers had indeed significantly increased (p < 0.005) their level of physical activity compared with a control group of nonexercisers.

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Among the same subjects, a positive correlation was found between changes in energy expenditure and changes in V02max over the first 6 months (r = 0.33; p < 0.05). After the same period of time, increases in energy expenditure were also associated with decreases in percentage body fat (r = -0.50; p < 0.01). In the third study, male and female subjects in an employee health promotion programme (n = 1561) were found to have significantly increased (p < 0.004) their energy expenditure over 12 months, accompanied by a significant increase (p < 0.001) in estimated V02max. The fourth study, a school teacher health promotion study involving 117 subjects, used a shortened, self-administered version of the 7-day recall in which activities were classified as either moderate (3.0 to 5.9 METs) or vigorous (~ 6.0 METs). Following 10 weeks of intervention, treatment subjects showed a significant increase (p < 0.001) in daily energy expenditure when compared to control subjects. This difference was also supported by a significant increase in performance on a treadmill exercise test (p < 0.001). Further scrutiny of the 7-day recall questionnaire has recently been reported by Dishman and Steinhardt (1988), who examined both its reliability and concurrent validity among samples of university students. In I study (n = 158), an identical correlation (r = 0.81; p < 0.01) with that reported initially by Taylor et al. (1984) was obtained between the results of the 7-day recall and a 7-day activity log. In another study (n = 163), the sensitivity and test-retest reliability of the self-administered form of the questionnaire were examined. Increases in physical activity owing to participation in exercise classes (over 9 weeks) were detected by the 7-day recall, which revealed significant increases (p < 0.05) in total and vigorous energy expenditure. Because overall physical activity was affected by the exercise classes, the testretest reliability ofthe recall after 5 weeks (r = 0.58; p < 0.01) and from weeks 5 to 9 (r = 0.63; p < 0.01) were not high. However, the free-living portion of students' physical activity (excluding exercise classes) proved to be consistent over the 9 weeks (coefficient of internal consistency, PI, = 0.89


and 0.90 for total and vigorous activity recall, respectively). Finally, in a smaller study (n = 24) of trained and untrained males aged 18 to 31 years, 7-day recall was well correlated with V02max (r = 0.61; p < 0.01) and a concurrent activity history questionnaire, similar to the Minnesota LTPAQ (r = 0.83; p < 0.01). As with other questionnaires, relationships have been examined between physical activity assessed by the 7-day recall and CHD risk factors. Sallis et al. (1988), in a study of volunteers in a family health promotion programme (206 families; 268 adults, 290 children), found no significant association among male adults between energy expenditure and any risk factors, although for female adults, energy expenditure was associated with body mass index (r = -0.16; p < 0.05) and a ratio of high density to low density lipoprotein (r = 0.15; p < 0.05). Among the children, the only association was found between female energy expenditure and the lipoprotein ratio (r = 0.25; p < 0.01). Since a simple, global, age and sex compared activity rating ('much less active' to 'much more active') was found to be more strongly related to CHD risk factors, Sallis and his colleagues suggested that the 7-day recall questionnaire, ' ... may be an unstable estimate of overall activity patterns, and a measure of 'usual' activity, although crude, may be more appropriate in some situations.' They therefore implied that instruments such as the 7-day recall, which are sensitive to changes in physical activity patterns over relatively short periods of time, may be more suitable for use with lifestyle intervention studies. These latter comments are very pertinent to the current status of physical activity questionnaire design. They highlight the main problem of establishing a 'one-for-alI' questionnaire, that is, obtaining the correct balance between specificity and generalisability. Until such an instrument is developed, reliable and valid questionnaires such as the 7-day recall are likely to remain popular choices. 2.2.5 3-Month Habitual Activity Questionnaire Reported in 1985 by Verschuur and Kemper (1985), this questionnaire could be viewed as being a compromise between the Minnesota LTPAQ and


the 7-day recall described above. During a 10- to 15-minute interview, information was gathered on the average weekly time spent during the previous three months in each of 3 categories of activities, the minimum intensity of which was 4 METs. Sports and nonsports activities were assessed separately. Activity categories were labelled 'light' (4 to 7 METs), 'medium-heavy' (7 to 10 METs) and heavy (~ 10 METs). Time spent per week per category was multiplied by a fixed intensity value assigned to each category: 5.5 METs (light), 8.5 METs (medium-heavy) and 11.5 METs (heavy). These were added to give a total weekly MET score for sports and nonsports activities. Surprisingly, no reports of the reliability and validity of this questionnaire have appeared, though it was used to study the effects of physical activity and strenuous exercise on salivary immunoglobulin A levels (thought to have a protective role against infection of the upper respiratory tract) in 199 young Dutch adults (Schouten et al. 1988). In general, however, no relationship was demonstrated between salivary immunoglobulin A and activity levels. 2.2.6 Other Post-1978 Physical Activity Questionnaires Most of the following questionnaires have either been purposely developed for use in particular studies or are relatively new and awaiting further examination in order that they may be established as reliable and valid alternatives. Many of them assess LTPA only and are self-administered. The only questionnaire to focus on light physical activities, defined as walking, cycling or gardening, was reported by Magnus et al. (1979). A random sample of 891 males and females from a Dutch community (aged 35 to 69 years) were required to indicate the number of months per year and the number of hours per week they participated in light exercise. This determined whether respondents were habitual (> 8 months per year), seasonal (4 to 8 months per year) or occasional « 4 months per year) participants of walking, cycling or gardening (WCG). It was found that there was a significant negative relationship between the oc-

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currence of acute coronary events and participation in WCG (p < 0.05). In addition, this relationship was independent of the number of hours per week devoted to WCG, and was not enhanced by participation in any extra, more vigorous exercise. There have been no reports assessing the reliability and validity of this unique questionnaire, though the above study does suggest there is scope for further investigations into the possible protective value of low intensity exercise, particularly among sedentary persons. Baecke et al. (1982) developed a short, self-administered questionnaire that assessed physical activity in three conceptually distinct categories: (a) physical activity at work; (b) sport during leisuretime; (c) physical activity during leisure-time excluding sport. Principal component analysis classified 16 questions into these groups - 8 were concerned with category (a), 4 were concerned with category (b), and 4 were concerned with category (c). For categories (a) and (c), questions were scored on a 5-point scale from 'never' (1 point) to 'very often' (5 points) and summed to give separate indices. Category (b), sport, was scored by a combination of the intensity of the sport which was played, the amount of time per week playing that sport, and the proportion of the year in which the sport was played regularly. The sum scores of each sport formed a sport index. The Baecke questionnaire was tested on young Dutch males (n = 139) and females (n = 167) aged 20 to 32 years. Three-month test-retest reliability was found to be good, product-moment correlations being r = 0.88 (work index), r = 0.81 (sport index) and r = 0.74 (nonsport leisure-time index). These indices have been compared with 3 other estimates of physical activity in the exercise-intervention study of 255 postmenopausal women (Cauley et al. 1987), mentioned previously. Among the exercise group, the objective measure, the LSI monitor, had low correlations of r = 0.20 and 0.17 (p < 0.05) with the leisure-time and sport index, respectively. Kilocalories per week, assessed by the Paffenbarger Physical Activity Questionnaire, had an equally modest association with the leisure-time index (r = 0.19; P < 0.01), but a better association

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with the sport index (r = 0.48; p < 0.01). Only the work index was found to be significantly associated with the third measure, energy intake (r = 0.31; p < 0.01). Among the control group, significant correlations were only found between the LSI and the leisure-time index (r = 0.16; p < 0.05), the Paffenbarger index and the leisure-time index (r = 0.36; p < 0.01) and the Paffenbarger index and the sport index (r = 0.26; p < 0.01). Further attempts at validating the instrument (Baecke et al. 1982) have been limited to a comparison with lean body mass (LBM). Multiple regression analysis showed a positive relationship among males only between LBM and the work index and the sport index (p < 0.01). It is unfortunate that no other studies using this questionnaire have been reported, since it is one of the few developed that allows separate analysis of sporting and nonsporting leisure-time activities. A brief, self-administered, 2-part LTPA questionnaire, recently described by Tuomilehto et al. (1987), was used in a cross-sectional survey of3975 Finnish males aged 25 to 64 years. Subjects had to indicate which types of physical activities they were usually engaged in and how frequently they practised these for at least 20 to 30 minutes. Activities were grouped into 4 categories according to their average intensity, ranging from 1 MET (no physical activity other than reading, watching TV, etc.) to 12 METs (running, crosscountry skiing, ballgames etc.). An LTPA index was calculated as the frequency (graded 1 to 5) multiplied by the MET value, giving a range of 1 to 60 units. No reports of reliability for this questionnaire have been described, although among the above sample, indirect validation was provided by an observed relationship between the LTPA index and body mass index (p < 0.001). In the same study, a significant (p < 0.0001) inverse relationship was found between LTPA and a composite index of eHD risk (comprising diastolic blood pressure, smoking and serum cholesterol). An LTPA questionnaire was developed by Morrison et al. (1984) in an attempt to establish whether leisure-time exercise has a 'threshold' effect on coronary risk factors. During a detailed interview,


subjects were asked about their weekly LTPA and were assigned to 1 of 8 activity groups. Group 1 represented no exercise, group 8 represented activities such as running, squash or tennis performed 4 or more times per ·week. Groups 2 to 4 represented 'light' exercise (such as golf, bowls, keep-fit, yoga or 30 minutes' walking, performed with varying frequency) and groups 5 to 8 represented 'strenuous' exercise. Among 1015 Zimbabweans (646 males, 369 females) aged 20 to 70 years, LTPA group was significantly correlated with V02max (r =0.61; p < 0.001). Further indirect validation was indicated by a negative relationship between percentage body fat and activity group (p < 0.01) among both males and females. These findings, coupled with a significant negative association between activity group and smoking (r = -0.24; p < 0.001) and a relationship between activity group and abnormal exercise electrocardiogram response (p < 0.05), prompted the authors to conclude that their LTPA questionnaire had confirmed a threshold level of exercise might exist, above which there is indeed a reduction in coronary risk. However, this threshold level was not specified. No reports of reliability or further validity have appeared for this instrument. A similar ordinal scale of physical activity was used in a study of 499 British male volunteers (aged 20 to 69 years) who attended a private fitness assessment unit (Bland & Williams 1988). From responses to standard questions asked by a doctor covering the type, frequency and duration of any weekly exercise taken (including work), subjects were assigned an activity rating on a scale of 1 to 7. Rating 1 was described as 'sedentary' (no exercise of any kind), rating 4 was 'active' (regular exercise, 3 to 6 times per week, but not endurance type) and rating 7 was 'endurance-trained' (exercise in excess of 5 to 6 times per week - greater than 3 hours - at 50 to 85% of V02max). Physical activity levels, independent of age, were found to influence health-related parameters; resting pulse rate, bodyweight, and body fat percentage all progressively decreased with increasing levels of activity, while V02max increased (correlations not reported).


Although no further reports using this particular procedure have appeared, its initial discriminating ability suggests that it, or an equally simple item such as the previous questionnaire, could be an attractive alternative for large-scale application. In their attempt to develop the 'ideal' measure of LTPA that was reliable, valid, simple, easy to score, representative of typical behaviour and devoid of the limitations connected with energy expenditure values, Godin and Shephard (1985) and Godin et al. (1986) offered 2 alternative questionnaires. The first (Godin & Shephard 1985) required subjects to indicate the average number of times per week they participated in 'strenuous' (heart beats rapidly), 'moderate' (not exhausting) and 'mild' (minimal effort) exercise, lasting more than 15 minutes. A second question asked about the weekly frequency of engaging in regular activity long enough to work up a sweat. The questionnaire was examined among 306 self-selected adults (163 males, 143 females) aged 18 to 65 years. Two-week test-retest reliability was assessed among a separate population of 53 subjects and revealed correlations of 0.94, 0.46, 0.48 and 0.74 for strenuous, moderate, mild and total activities, respectively. Apart from the strenuous category, these correlations are surprisingly low for such a nons~ific questionnaire. Validation among the larger sample was attempted with percentile (relative to age and sex) measures of estimated V02max and percentage body fat. Correlation between LTPA and V02max were low, but significant (p < 0.001) for total and strenuous activity only; r = 0.24 and 0.38, respectively. Total and strenuous categories were also significantly (p < 0.001) related to body fat (r = 0.13 and 0.21, respectively). Additional discriminant function analyses indicated that the questionnaire items were able to discriminate the majority of 'fit' (V02max scores above the fiftieth percentile) from 'unfit' (V02max below the fiftieth percentile) people, and the majority of 'thin' (body fat below fiftieth percentile) from 'fat' (body fat above fiftieth percentile) people. The implication here is that LTPA questionnaires have the potential for actually being em-

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ployed as alternative, and less involved, estimates of fitness and body composition. The second questionnaire (Godin et at. 1986) comprised just I question; 'How often did you participate in activities long enough to get sweaty, during leisure-time within the past four months?' Responses were assigned numeric values as follows: 'not at all', 0; 'less than once a month', 2; 'about once a month', 4; 'about 2 or 3 times a month', 10; 'about I to 2 times a week, 24; 'three or more times a week', 48. The 2-week test-retest reliability of the question among 29 male (aged 21 to 62 years) subjects in a fitness study was not high (r = 0.64; p not reported). The same validity criteria as for the former questionnaire were adopted (V02max and body fat), with the addition of a measure of muscular endurance (sit-ups), among a different group of 61 self-selected adults, aged 19 to 66 years. Level of (strenuous) activity over the past 4 months was found to be significantly correlated (p < 0.01) with each validity criteria (r = 0.38, 0.43 and 0.54 for V02max body fat and muscular endurance percentiles, respectively). When dichotomised at the median (fiftieth percentile) into 'high' and 'low' categories, a significant relationship was observed between each validity criteria and level of physical activity (p < 0.05). Further reports using either questionnaire have not appeared in the literature. While both these LTPA questionnaires are crude and represent overall indicators of physical activity, they do consider the intensity of physical activity, which is known to affect directly fitness levels, and indirectly CHD risk. The same can be said for a question used by Mundal et al. (1987), which simply asked 'What is your physical activity during leisure hours?' A choice of 6 responses included 'No physical activity, or only occasional light exercise', 'Training at least twice a week (i.e. performing exercise to the level of sweating or getting out of breath' and 'Participating regularly in strenuous athletic competitions'. However, the absence of such emphasis does not necessarily render a questionnaire invalid. For example, a question asked by Hopkins et al. (1987a) to rate the subjects' general level of activity on a 9-point scale from 'very sedentary' to 'very active', was found to be

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correlated with V02max (r = 0.59; p < 0.01). Likewise, Forth and Salmoni (1988) have reported a correlation between perceived activity level (relative to own age) rated on a 5-point scale and V02max (r = 0.63; p < 0.05). Indeed, questions such as these may be favoured in interview surveys, for which time is a restrictive factor.

3. Current Trends The popular method of assessing energy expenditure in kilocalories per unit of time or classes of intensity (METs) during leisure-time has remained (Chen et a1. 1987; Cox et al. 1987; Drygas et al. 1988; Hopkins et al. 1987b; Parker et al. 1988; Slattery et al. 1988). However, despite recommendations made over 10 years ago (Gordis 1979), standardised questionnaire formats have yet to be established and universally adopted. Attempts are still being made to develop questionnaires that will clarify previously observed relationships between LTPA and CHD, health risks or cardiorespiratory fitness. For example, Parker et al. (1988) have devised a self-administered LTPA questionnaire that purports to account for individual exercise intensity. In terms of the calculation of energy expenditure, this approach attempts to eliminate the recognised limitation of using activity-specific energy cost values (or METs), which is that they do not account for variations in expenditure that occur owing to individual levels of exertion and physical fitness. While the questionnaire was found to be associated with various CHD risk factors among 166 adults (aged 23 to 63), such as body composition, total and HDL cholesterol, it required prior information on subjects' fitness levels, ascertained via an appropriate exercise test. Thus, it would not be suitable on its own for mass use. Owing to escalating concern over preventive medicine and self-care, large population (up to national level) surveys pertaining to health and fitness are now being carried out with increasing frequency. Most have included (or will include) an assessment of LTPA and/or HBA in their survey procedures (Cox et al. 1987; Fasting 1982; Welsh Heart Health Survey 1985). In addition, more at-


tention is presently being paid to the physical activity habits of children (Lifetime of Health and Fitness Survey 1988; Marti & Vartiainen 1989; Northern Ireland Health and Fitness Survey 1988), in spite of past doubts about the reliability and validity of information obtained from them (Baranowski et al. 1984; Forth & Salmoni 1988). An interest is now being shown in examining the physical activity of the elderly (Dallosso et al. 1988), for whom involvement in all but low intensity activity is limited. These are important areas of research, since such members of the community, along with the unemployed and other underprivileged groups, may have even more to gain from leisure-time physical activity.

4. Conclusions This review has highlighted the many attempts that have been made to measure leisure-time physical activity by questionnaire. Two main approaches have been consistently employed. One has sought to gather exact information about participation in specific activities, thereby giving a measure of energy expenditure. The other, tending to be far simpler and quicker, has provided a more general, less quantitative appraisal of LTPA activity, often on a scale ranging from 'active' to 'inactive'. Having presented descriptions of their content, validity, reliability and applications, we conclude that it is difficult, and probably inappropriate, to make firm recommendations regarding the choice of specific questionnaires for measuring LTPA. This is because for any future study the level of detail of physical activity required, the type and size of population to be studied, and the relationships to be investigated must be considered in the selection process. Similarly, the constraints on the research programme, such as time, cost, and availability of trained personnel, will dictate the choice of questionnaire to be used. In addition, reliability and validity are prerequisites of any measuring tool, and in many of those questionnaires reviewed above, these were found to have been inadequately investigated. All LTPA questionnaires have one feature in


common - they rely on subjective reports of behaviour - and it has been shown that the amount of detail obtained concerning such behaviour is the principal discriminating feature of individual questionnaires. At one extreme, it has been described that subjects can be asked to recall every physical activity lasting 5 minutes or more performed during 24 hours, at the other, they can be asked to summarise their overall or general level of activity (possibly compared to someone of the same age). For the sake of efficiency (i.e. time, personnel, cost) the latter enquiry would be more acceptable in large-scale epidemiological studies, in which LTPA was only one of many variables under observation. The detail obtained by the former enquiry on the other hand, would be of more value in small-scale, lifestyle intervention programmes in which the extent of behavioural modification needs to be monitored. Whichever option is chosen, however, considerable uncertainty still exists as to the accuracy of self-reported physical activity (Baranowski 1988), especially where questionnaires demand detailed recall. Moreover, the fundamental problem remaining is how much information on physical activity levels, leisure-time or habitual, is actually required in order to study individual or population differences and their associations with health risk factors optimally. With these comments in mind, there remains much that can be done in order to explore the potential of LTPA questionnaires. For example, correlations so far reported indicate that an assessment of LTPA may well be a useable surrogate measure of cardiorespiratory fitness. This could have direct implications for future mass fitness assessment programmes. For existing and future questionnaires there is a definite need to place more emphasis on establishing their reliability and validity among populations other than middle-aged males, whose spectra of physical activity has frequently been narrow. In addition, with the current impetus to monitor national levels of physical activity, attempts at creating some degree of standardisation is also desirable in order that meaningful interpopulation comparisons can be made. We thus recommend that a future approach to

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assessing LTPA by questionnaire should concentrate on: (a) the further validation of existing items; (b) ensuring that questionnaire reliability is established; (c) an examination of population specificity, for example, to see whether certain items are more suitable for children, the aged, disabled, etc.; and (d) establishing a 'code of practice' or position statement to be observed world-wide.

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Correspondence and reprints: K.L. Lamh. Department of Movement Science and Physical Education. University of Liverpool. 20 Oxford Street, Liverpool. L69 3BX. England.

1st International 'Drugs' Congress

New Therapeutic Approaches in Asthma, Bronchitis and Rhinitis Date: 19-22 March 1991 Venue: Nice, France For further information, please contact: Adis International Ltd The Old Palace Little t John treet Chester CHI IRE

ENGLAND

Comparison of physical activity using questionnaires (leisure time physical activity instrument and physical activity at home and work instrument) and accelerometry in fibromyalgia patients: the Al-Ándalus project.

Accelerometry and physical activity questionnaires - a systematic review.

Assessment of physical activity, and physical fitness, in population surveys.

Comparison of two physical activity questionnaires, with a diary, for assessing physical activity in an elderly population.

Assessment of physical activity: an international perspective.

Assessment of physical activity in older adults.

The Lancet Physical Activity Observatory: promoting physical activity worldwide.

Subjective Estimation of Physical Activity Using the International Physical Activity Questionnaire Varies by Fitness Level.

Issues in the assessment of physical activity in women.

The current state of physical activity assessment tools.

Measurement issues in the assessment of physical activity in children.

A longitudinal assessment of the links between physical activity and physical self-worth in adolescent females.

Lack of physical activity.

Physical function and physical activity assessment and promotion in the hemodialysis clinic: a qualitative study.

Assessment of physical activity of patients with chronic pain.

Validity and reliability of two brief physical activity questionnaires among Spanish-speaking individuals of Mexican descent.

Objective Assessment of Physical Activity: Classifiers for Public Health.

A social ecological assessment of physical activity among urban adolescents.

Comparison of IPAQ-SF and Two Other Physical Activity Questionnaires with Accelerometer in Adolescent Boys.

Retirement and physical activity.

[Physical activity in pregnancy].

Physical activity and hormones.

[Physical activity -- preventing dementia].

Physical activity and exercise.