Journal of Sports Sciences
ISSN: 0264-0414 (Print) 1466-447X (Online) Journal homepage: http://www.tandfonline.com/loi/rjsp20
Gross efficiency responses to exercise conditioning in adult males of various ages C. Gissane , D.L. Corrigan & J.A. White To cite this article: C. Gissane , D.L. Corrigan & J.A. White (1991) Gross efficiency responses to exercise conditioning in adult males of various ages, Journal of Sports Sciences, 9:4, 383-391, DOI: 10.1080/02640419108729898 To link to this article: http://dx.doi.org/10.1080/02640419108729898
Published online: 14 Nov 2007.
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Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=rjsp20 Download by: [Ryerson University Library]
Date: 06 October 2016, At: 10:24
Journal of Sports Sciences, 1991, 9, 383-391
Gross efficiency responses to exercise conditioning in adult males of various ages C. GISSANE,1* D.L. CORRIGAN2 and J.A. WHITE3 1
Department of Health and Paramedical Studies, West London Institute of Higher Education, Isleworth, Middlesex, UK, 2Department of Physical Education, Health and Recreation Studies, Purdue University, West Lafayette, Indiana 47907, USA and 3Division of Sport and Leisure Studies, University of Ulster at Jordanstown, Newtonabbey, Co. Antrim, UK
Accepted 18 December 1990
Abstract This study investigated gross efficiency changes in a group of 60 adult males (mean age 39.2 ± 1.2 years) resulting from endurance training and age-related responses to such training in sub-groups (each n = 20) of younger (30.7 ± 0.7 years), intermediate (38.3 ± 0.5 years) and older (48.6 ± 1.1 years) subjects. Gross efficiency (%) was calculated from work output, oxygen consumption and RER energy equivalents following 10 min standard cycle ergometry exercise at 100 W and 50 rev min -1 . Measurements were made at pre-, mid- and post-8 months of training, which involved progressive walking/jogging activities designed to enhance endurance capacity. In the total group, VO2 decreased pre- to post-training from 2.15 ± 0.02 to 1.93 ± 0.01 1 min -1 (P < 0.01). In the sub-groups, both the younger and older subjects showed a significantly reduced VO2, from 2.17 ± 0.01 to 1.98 ± 0.04 1 min -1 and 2.05 ± 0.08 to 1.86 ± 0.03 1 min - 1 respectively (P < 0.05), but no significant changes were noted at mid-training. In the intermediate age subjects, while there were trends towards a reduced VO 2 , none was significant. The ANOVA revealed increased mean gross efficiency in the total group from pre(14.3 ± 0.1%) to post- (15.5 ± 0.2%) (P < 0.05) but not at mid-training (14.8 ± 0.2%). While similar trends were observed in the sub-groups, gross efficiency increases were not significant, although changes in gross efficiency were reflected in VO 2 . The findings suggest that during standardized exercise, oxygen cost may be reduced and gross efficiency increased in adult males following endurance training and that such changes may take place over a variety of age ranges. Keywords: Gross efficiency, exercise conditioning, males.
Introduction One laboratory test to assess the cardiorespiratory fitness is the determination of maximal oxygen consumption (VO2 max). However, the inability of subjects to satisfy the necessary criteria for VO2 max has been reported (Cumming and Borysyk, 1972; Sidney and Shephard, 1977). Because of the difficulty in obtaining valid measures of VO2 max, especially in older subjects, some have attempted to estimate f^O2 max from submaximal heart rate data, but this procedure also has its limitations (Davies, 1968; Sidney and Shephard, 1977). *To whom all correspondence should be addressed. 0264-0414/91 $03.00 + .12 © 1991 E. & F.N. Spon Ltd.
384
Gissane et al.
In view of the drawbacks associated with the measurement and/or prediction of VO2 max, perhaps gross efficiency could be considered as a useful indicator of relative conditioning, since the relative intensity of a bout of exercise can be influenced in one of two possible ways: either a change in VO2 max or in VO2 for any given workload. The measure of gross efficiency may provide a useful tool for the identification of conditioning status changes at submaximal work levels. Efficiency can be calculated from a lower relative intensity of exercise than either VO2 max or the levels needed for submaximal prediction of VO2 max (Cavanagh and Kram, 1985). The determination of efficiency, therefore, has the advantage of allowing a greater proportion of older subjects to complete the protocol safely and satisfactorily (ACSM, 1986), and since it is a direct measure, it is therefore not subject to estimation errors involved in prediction procedures. Changes in efficiency as a result of training have shown conflicting findings. Some have reported improved efficiency (Badenhop et al., 1983; Bransford and Howley, 1977; Conley et al., 1981; Ekblom et al., 1968; Margaria et al., 1963; Mayers and Gutin, 1979; Sidney and Shephard, 1978; Stuart et al., 1981), whereas others have reported no change (DeVries, 1970; Dolenger, 1982; Girondola and Katch, 1973; Niinimaa and Shephard, 1978; Saltin et al., 1969). Some report economy (oxygen cost), rather than efficiency (work accomplished to energy expended) (Badenhop et al., 1983; Bransford and Howley, 1977; Conley et al., 1981; DeVries, 1970; Dolenger et al., 1982; Ekblom et al., 1968; Niinimaa and Shephard, 1978), so that changes in respiratory exchange ratio (RER) have been largely unreported. Secondly, most data are from either young or athletic individuals (Bransford and Howley, 1977; Margaria et al., 1963; Mayers and Gutin, 1979; Stuart et al., 1981). Thirdly, it has been reported that interval training is more effective than either sprint or endurance training for improving economy and/or efficiency (Conley et al., 1981). Fourthly, almost all studies have reported data that had been collected over relatively short time periods and only one study (DeVries, 1970) monitored changes over a similar period to the present study (8 months). Studies on efficiency have focused on the identification of an operational definition (Gaesser and Brooks, 1975), and the external factors that influence the efficiency of movement, e.g. workload, speed of movement and seat height (Hagberg et al., 1981; Merrill and White, 1984). Some have only investigated the economy (in terms of oxygen cost) with which exercise is performed, and how it is affected by training (Bransford and Howley, 1977). Daniels (1985) viewed the concept of 'economy' as more straightforward than metabolic efficiency determinations, and suggested that future research should deal with how exercise and differing types of training can improve 'economy' in trained subjects. However, the concept of efficiency of exercise (work accomplished to energy expended) may have more relevance to the health and fitness aspirations of adult populations who tend to engage in low-level, steady-state activities, rather than optimal measures of aerobic power which reflect upper tolerance limits for aerobic power. The purpose of the present study was to investigate the influence of an 8-month training programme on the gross efficiency (as defined by Lamb, 1984) of male subjects during submaximal steady-state exercise, and to assess the influence of age.
Methods The subjects who participated in this study were 109 males aged between 23 and 63 years. Each was a volunteer from the Purdue Adult Fitness Programme who had agreed to follow
Gross efficiency changes with exercise conditioning
385
an individually supervised exercise conditioning programme of an hour's duration, three times per week for 8 months. The activity session included 15-20 min of callisthenics. The subjects walked/ran an assigned - and progressively increased - number of laps on an indoor track, with the emphasis placed on distance, so that the majority of subjects, who had been sedentary initially, could jog/run 4 miles (6.4 km) continuously at the end of the programme. After running, the subjects performed games activities or light callisthenics as they wished. Of the original number of subjects, 69 satisfied an 80% minimum attendance requirement for inclusion in the subsequent data analyses. In order to analyse the differences in training responses between younger, intermediate and older males, the subjects were designated into three experimental groups (each « = 20): younger (x = 30.7 ±0.7 years, range 25-33 years), intermediate (x=38.3+0.5 years, range 35-41 years) and older (x=48.6±l.l years, range 45-61 years). The data that were collected on the remaining nine subjects were eliminated because their ages were at the transition of the respective age group classifications. Gross efficiency was determined on a Monark cycle ergometer (model no. 868), adjusted for the individual's height. The subjects' expired air was collected via a mouthpiece and a flexible plastic tube to a Beckman Metabolic Cart for oxygen and carbon dioxide analyses and heart rate was monitored from an ECG. The subjects performed a progressive cycling warm-up of 1 min intervals at 25, 50 and 75 W at 50 rev min" 1 . During the assessment of exercise efficiency, the subject cycled at the same pedal frequency for 10 min at 100 W. After 10 min, each subject was asked to continue cycling at 50 rev min" x with increments in work rate of 25 W until a voluntary maximum level was achieved for determination of peak aerobic power (highest VO2 attained) at the pre-conditioning programme test. Expired gas and heart rate were analysed during the final minute of exercise at 100 W and at the initial voluntary work rate. The same incremental external workload assessment procedures were undertaken at the beginning (pre-), at approximately the middle (mid-) and at the completion (post-) of the conditioning programme for each of the subjects, using the same endpoint exercise work rate established in the pre-conditioning test. This initial voluntary maximal level of work was held constant to determine the adaptation to the exercise conditioning programme over the 8-month period of the study. Since submaximal VO2 has been reported to reach a steady state between 5 and 6 min (McConnell and Sinning, 1980) and the time required for RER to reach steady-state has also been reported to range from 2 (McConnell and Sinning, 1980) to 4 min (Issekutz and Rodahl, 1961), the 10-min duration of the exercise efficiency test was designed to allow both of these parameters to reach steady-state. Based on this assumption, in this study, gross efficiency was defined as the total relative (external/internal) energy cost of a given activity incorporating RER into the calculation of efficiency according to the formula of Lamb (1984), where: ^ cc • , n n „ , / n / \ external work at 100 W (kcal min" 11) x Gross efficiency at 100 W (%) = —= —r-rr TT^~,—:—rr VO2 (1 min 1 ) x RER (kcal min" 1 )
10
°
where 100 W requires approximately 1.41 kcal min" 1 (Lamb, 1984), and RER (kcal min" 1 ) represents the equivalent energy contribution from relative fat and carbohydrate sources based upon the ratio KCO 2 /KO 2 (Carpenter, 1964). The data were analysed using two-way nested factorial analysis of variance (ANOVA), after the data had been checked for homogeneity of variance using Hartley's F max test. Where a significant F ratio was established, a multiple comparison of mean values was performed
386
Gissane et al.
using the Student Newman-Keuls range test in order to identify the mean values contributing to overall significance. The significance was set at P
ISSN: 0264-0414 (Print) 1466-447X (Online) Journal homepage: http://www.tandfonline.com/loi/rjsp20
Gross efficiency responses to exercise conditioning in adult males of various ages C. Gissane , D.L. Corrigan & J.A. White To cite this article: C. Gissane , D.L. Corrigan & J.A. White (1991) Gross efficiency responses to exercise conditioning in adult males of various ages, Journal of Sports Sciences, 9:4, 383-391, DOI: 10.1080/02640419108729898 To link to this article: http://dx.doi.org/10.1080/02640419108729898
Published online: 14 Nov 2007.
Submit your article to this journal
Article views: 21
View related articles
Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=rjsp20 Download by: [Ryerson University Library]
Date: 06 October 2016, At: 10:24
Journal of Sports Sciences, 1991, 9, 383-391
Gross efficiency responses to exercise conditioning in adult males of various ages C. GISSANE,1* D.L. CORRIGAN2 and J.A. WHITE3 1
Department of Health and Paramedical Studies, West London Institute of Higher Education, Isleworth, Middlesex, UK, 2Department of Physical Education, Health and Recreation Studies, Purdue University, West Lafayette, Indiana 47907, USA and 3Division of Sport and Leisure Studies, University of Ulster at Jordanstown, Newtonabbey, Co. Antrim, UK
Accepted 18 December 1990
Abstract This study investigated gross efficiency changes in a group of 60 adult males (mean age 39.2 ± 1.2 years) resulting from endurance training and age-related responses to such training in sub-groups (each n = 20) of younger (30.7 ± 0.7 years), intermediate (38.3 ± 0.5 years) and older (48.6 ± 1.1 years) subjects. Gross efficiency (%) was calculated from work output, oxygen consumption and RER energy equivalents following 10 min standard cycle ergometry exercise at 100 W and 50 rev min -1 . Measurements were made at pre-, mid- and post-8 months of training, which involved progressive walking/jogging activities designed to enhance endurance capacity. In the total group, VO2 decreased pre- to post-training from 2.15 ± 0.02 to 1.93 ± 0.01 1 min -1 (P < 0.01). In the sub-groups, both the younger and older subjects showed a significantly reduced VO2, from 2.17 ± 0.01 to 1.98 ± 0.04 1 min -1 and 2.05 ± 0.08 to 1.86 ± 0.03 1 min - 1 respectively (P < 0.05), but no significant changes were noted at mid-training. In the intermediate age subjects, while there were trends towards a reduced VO 2 , none was significant. The ANOVA revealed increased mean gross efficiency in the total group from pre(14.3 ± 0.1%) to post- (15.5 ± 0.2%) (P < 0.05) but not at mid-training (14.8 ± 0.2%). While similar trends were observed in the sub-groups, gross efficiency increases were not significant, although changes in gross efficiency were reflected in VO 2 . The findings suggest that during standardized exercise, oxygen cost may be reduced and gross efficiency increased in adult males following endurance training and that such changes may take place over a variety of age ranges. Keywords: Gross efficiency, exercise conditioning, males.
Introduction One laboratory test to assess the cardiorespiratory fitness is the determination of maximal oxygen consumption (VO2 max). However, the inability of subjects to satisfy the necessary criteria for VO2 max has been reported (Cumming and Borysyk, 1972; Sidney and Shephard, 1977). Because of the difficulty in obtaining valid measures of VO2 max, especially in older subjects, some have attempted to estimate f^O2 max from submaximal heart rate data, but this procedure also has its limitations (Davies, 1968; Sidney and Shephard, 1977). *To whom all correspondence should be addressed. 0264-0414/91 $03.00 + .12 © 1991 E. & F.N. Spon Ltd.
384
Gissane et al.
In view of the drawbacks associated with the measurement and/or prediction of VO2 max, perhaps gross efficiency could be considered as a useful indicator of relative conditioning, since the relative intensity of a bout of exercise can be influenced in one of two possible ways: either a change in VO2 max or in VO2 for any given workload. The measure of gross efficiency may provide a useful tool for the identification of conditioning status changes at submaximal work levels. Efficiency can be calculated from a lower relative intensity of exercise than either VO2 max or the levels needed for submaximal prediction of VO2 max (Cavanagh and Kram, 1985). The determination of efficiency, therefore, has the advantage of allowing a greater proportion of older subjects to complete the protocol safely and satisfactorily (ACSM, 1986), and since it is a direct measure, it is therefore not subject to estimation errors involved in prediction procedures. Changes in efficiency as a result of training have shown conflicting findings. Some have reported improved efficiency (Badenhop et al., 1983; Bransford and Howley, 1977; Conley et al., 1981; Ekblom et al., 1968; Margaria et al., 1963; Mayers and Gutin, 1979; Sidney and Shephard, 1978; Stuart et al., 1981), whereas others have reported no change (DeVries, 1970; Dolenger, 1982; Girondola and Katch, 1973; Niinimaa and Shephard, 1978; Saltin et al., 1969). Some report economy (oxygen cost), rather than efficiency (work accomplished to energy expended) (Badenhop et al., 1983; Bransford and Howley, 1977; Conley et al., 1981; DeVries, 1970; Dolenger et al., 1982; Ekblom et al., 1968; Niinimaa and Shephard, 1978), so that changes in respiratory exchange ratio (RER) have been largely unreported. Secondly, most data are from either young or athletic individuals (Bransford and Howley, 1977; Margaria et al., 1963; Mayers and Gutin, 1979; Stuart et al., 1981). Thirdly, it has been reported that interval training is more effective than either sprint or endurance training for improving economy and/or efficiency (Conley et al., 1981). Fourthly, almost all studies have reported data that had been collected over relatively short time periods and only one study (DeVries, 1970) monitored changes over a similar period to the present study (8 months). Studies on efficiency have focused on the identification of an operational definition (Gaesser and Brooks, 1975), and the external factors that influence the efficiency of movement, e.g. workload, speed of movement and seat height (Hagberg et al., 1981; Merrill and White, 1984). Some have only investigated the economy (in terms of oxygen cost) with which exercise is performed, and how it is affected by training (Bransford and Howley, 1977). Daniels (1985) viewed the concept of 'economy' as more straightforward than metabolic efficiency determinations, and suggested that future research should deal with how exercise and differing types of training can improve 'economy' in trained subjects. However, the concept of efficiency of exercise (work accomplished to energy expended) may have more relevance to the health and fitness aspirations of adult populations who tend to engage in low-level, steady-state activities, rather than optimal measures of aerobic power which reflect upper tolerance limits for aerobic power. The purpose of the present study was to investigate the influence of an 8-month training programme on the gross efficiency (as defined by Lamb, 1984) of male subjects during submaximal steady-state exercise, and to assess the influence of age.
Methods The subjects who participated in this study were 109 males aged between 23 and 63 years. Each was a volunteer from the Purdue Adult Fitness Programme who had agreed to follow
Gross efficiency changes with exercise conditioning
385
an individually supervised exercise conditioning programme of an hour's duration, three times per week for 8 months. The activity session included 15-20 min of callisthenics. The subjects walked/ran an assigned - and progressively increased - number of laps on an indoor track, with the emphasis placed on distance, so that the majority of subjects, who had been sedentary initially, could jog/run 4 miles (6.4 km) continuously at the end of the programme. After running, the subjects performed games activities or light callisthenics as they wished. Of the original number of subjects, 69 satisfied an 80% minimum attendance requirement for inclusion in the subsequent data analyses. In order to analyse the differences in training responses between younger, intermediate and older males, the subjects were designated into three experimental groups (each « = 20): younger (x = 30.7 ±0.7 years, range 25-33 years), intermediate (x=38.3+0.5 years, range 35-41 years) and older (x=48.6±l.l years, range 45-61 years). The data that were collected on the remaining nine subjects were eliminated because their ages were at the transition of the respective age group classifications. Gross efficiency was determined on a Monark cycle ergometer (model no. 868), adjusted for the individual's height. The subjects' expired air was collected via a mouthpiece and a flexible plastic tube to a Beckman Metabolic Cart for oxygen and carbon dioxide analyses and heart rate was monitored from an ECG. The subjects performed a progressive cycling warm-up of 1 min intervals at 25, 50 and 75 W at 50 rev min" 1 . During the assessment of exercise efficiency, the subject cycled at the same pedal frequency for 10 min at 100 W. After 10 min, each subject was asked to continue cycling at 50 rev min" x with increments in work rate of 25 W until a voluntary maximum level was achieved for determination of peak aerobic power (highest VO2 attained) at the pre-conditioning programme test. Expired gas and heart rate were analysed during the final minute of exercise at 100 W and at the initial voluntary work rate. The same incremental external workload assessment procedures were undertaken at the beginning (pre-), at approximately the middle (mid-) and at the completion (post-) of the conditioning programme for each of the subjects, using the same endpoint exercise work rate established in the pre-conditioning test. This initial voluntary maximal level of work was held constant to determine the adaptation to the exercise conditioning programme over the 8-month period of the study. Since submaximal VO2 has been reported to reach a steady state between 5 and 6 min (McConnell and Sinning, 1980) and the time required for RER to reach steady-state has also been reported to range from 2 (McConnell and Sinning, 1980) to 4 min (Issekutz and Rodahl, 1961), the 10-min duration of the exercise efficiency test was designed to allow both of these parameters to reach steady-state. Based on this assumption, in this study, gross efficiency was defined as the total relative (external/internal) energy cost of a given activity incorporating RER into the calculation of efficiency according to the formula of Lamb (1984), where: ^ cc • , n n „ , / n / \ external work at 100 W (kcal min" 11) x Gross efficiency at 100 W (%) = —= —r-rr TT^~,—:—rr VO2 (1 min 1 ) x RER (kcal min" 1 )
10
°
where 100 W requires approximately 1.41 kcal min" 1 (Lamb, 1984), and RER (kcal min" 1 ) represents the equivalent energy contribution from relative fat and carbohydrate sources based upon the ratio KCO 2 /KO 2 (Carpenter, 1964). The data were analysed using two-way nested factorial analysis of variance (ANOVA), after the data had been checked for homogeneity of variance using Hartley's F max test. Where a significant F ratio was established, a multiple comparison of mean values was performed
386
Gissane et al.
using the Student Newman-Keuls range test in order to identify the mean values contributing to overall significance. The significance was set at P
