RESEARCH ARTICLE
Physical Fitness in Spanish Schoolchildren Aged 6-12 Years: Reference Values of the Battery EUROFIT and Associated Cardiovascular Risk ´ ´ ´ ROBERTO GUL´ıAS-GONZALEZ , PhDa MAIRENA SANCHEZ -LOPEZ , PhDb A´ NGEL OLIVAS-BRAVO, BSci Edc MONTSERRAT SOLERA-MART´ıNEZ, PhDd VICENTE MART´ıNEZ-VIZCA´ıNO, MD, PhDe
ABSTRACT BACKGROUND: Physical fitness is considered an important indicator of health in children. The aims of this study were to (1) provide sex- and age-specific EUROFIT battery levels of fitness in Spanish children; (2) compare Spanish children’s fitness levels with those of children from other countries; and (3) determine the percentage of Spanish children with cardiovascular risk associated with low cardiorespiratory fitness (CRF). METHODS: Physical fitness was assessed using the EUROFIT tests in 1725 children, aged 6 to 12, from Castilla-La Mancha, Spain. We derived specific values for physical fitness using LMS method. FITNESSGRAM 2010 criteria were used to estimate the percentage of children with cardiovascular risk associated with low CRF. RESULTS: Boys scored higher in all the physical fitness tests, except for the flexibility test. Physical fitness improved as age increased, except for flexibility, which worsened in boys, and VO2max, which decreased in both sexes. The prevalence of boys and girls with cardiovascular risk associated to low CRF was 13% and 26%, respectively. CONCLUSIONS: Specific fitness test scores for children and adolescents can represent the fitness status of schoolchildren accurately. Schools need to make efforts to improve the fitness level of the schoolchildren to prevent cardiovascular risk. Keywords: child and adolescent health; physical fitness and sport; public health. ´ Solera-Mart´ınez M, Mart´ınez-Vizca´ıno V. Physical fitness in Citation: Gul´ıas-Gonz´alez R, S´anchez-L´opez M, Olivas-Bravo A, Spanish schoolchildren aged 6-12 years: reference values of the battery EUROFIT and associated cardiovascular risk. J Sch Health. 2014; 84: 625-635. Received on October 25, 2012 Accepted on January 5, 2014
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hysical fitness is considered an important indicator of health in children and adolescents.1,2 High levels of cardiorespiratory fitness (CRF) in childhood are associated with increased cardiovascular, skeletal, and mental health,1,2 and improvements in muscular strength levels from childhood to adolescence are
associated with a decrease in total adiposity.2 Although less studied, speed/agility is strongly related to bone mineral density and bone mass accumulation in later stages of life.2-4 Low levels of physical fitness in childhood are associated with an increased risk of cardiovascular disease in adulthood.3-5 Furthermore,
a
Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. c Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. d Assistant Professor, ([email protected]), Social and Health Care Research Center; University of Castilla-La Mancha, Santa Teresa Jornet s/n, 16071 Cuenca, Spain. e Professor, ([email protected]), Social and Health Care Research Center, University of Castilla-La Mancha, Santa Teresa Jornet s/n, 16071 Cuenca, Spain. b
Address correspondence to: Roberto Gul´ıas-Gonz´alez, Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain The authors of this study express their appreciation and gratitude to all the schools, students, and teachers who participated in this study voluntarily. Also to all members involved in the fieldwork for their effort and enthusiasm. This study was funded by the Ministry of Education and Science through aid for the development of cooperation projects in the field of innovation and research among the faculty and nonuniversity teachers of the autonomous community of Castilla-La Mancha, Spain (Resolution 08/07/2009, the Deputy Ministry of Education of the Regional Government of Castilla-La Mancha). Data about physical fitness smoothed centile values for the EUROFIT battery of tests by sex and age in the schoolchildren are available from the corresponding author.
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the level of physical fitness in childhood is a predictor of physical fitness in adult life;2,5-8 therefore, to include measurements of physical fitness related to health in the education and health systems is clearly justified. In Spain, the main drivers behind the alarming trend of obesity prevalence in schoolchildren are richly debated. A possible way to try to clarify this issue is to compare the fitness levels of Spanish children with those of children in other countries where the prevalence of obesity is appreciably lower. Considering the consistently described relationship between daily physical activity and fitness levels, if the levels of fitness of Spanish children are lower than the levels in countries with lower obesity prevalence, such as northern European countries, the sedentary lifestyle could be considered as the main driver of the current obesity epidemic. To assess physical fitness, updated values for the target population are necessary. Owing to methodological differences in the protocols of assessment of physical fitness, comparing and interpreting the results between and among different population studies is complicated.9,10 EUROFIT battery has proven to be a simple, standardized, and practical instrument, with good reliability and validity.11-14 Traditionally, the program FITNESSGRAM has provided valid and reliable cutoff points for identifying children with future cardiovascular risk according to their level of CRF.15,16 However, improved standards developed with advanced statistical techniques (Receiver Operating Characteristic-ROC-curves) have recently been published. These new criteria allow the categorization of children into 3 fitness levels (Healthy Fitness Zone, Higher Risk, and Some Risk), thereby providing more specific and clearer information than the previous 2 categories (Healthy Fitness Zone and Needs Improvement Zone) established by traditional standards.17,18 Placing individuals and groups in percentiles and categories allow to identify individuals with low fitness levels and to implement interventions to promote healthy behaviors in order to prevent future cardiovascular risk. This study aimed to (1) assess the physical fitness of children, aged 6-12, from Castilla-La Mancha, Spain, according to sex and age; (2) compare our results with those of other European and international studies conducted in the same population group; and (3) estimate the prevalence of students who present future cardiovascular risk associated with low CRF, in schoolchildren aged 10-12 in Castilla-La Mancha, Spain.
schools randomly selected from the 778 schools in Castilla-La Mancha by multistage sampling. In each school, 2 boys and 2 girls were randomly selected per class, 1st to 6th grades. A sample size of 629 subjects was estimated by using EpiData 3.1 software (EpiData Association, Odense, Denmark), considering a prevalence of cardiovascular risk associated with low CRF of 18%,9 a confidence level of 95%, and 3% accuracy. Because we intended to maintain that accuracy in both sexes, and considering a nonresponse rate of 30%, the minimum sample size was estimated in 1635 students. Data from 2 population-based samples (Latvia and Australia) were used to compare data from Spanish students with data belonging to other countries. These samples were selected because of both of them employed the same fitness tests used in our study, and were also large samples from the same age range. Instruments and Procedure Measurements were carried out on the premises of each school between April and May 2010. Tests were carried out by researchers with Bachelor of Science degrees in physical activity and education, and by physical education teachers who had previously completed a 2-day training course to standardize measurements. Evaluation of physical fitness. In the gymnasium of each school, physical fitness was assessed using the 9 tests included in the EUROFIT battery:11,12 Flamingo Balance Test, Plate Tapping, Sit and Reach Test, Standing Broad Jump Test, Handgrip Test, Sit-ups in 30 seconds, Bent Arm Hang, 10 × 5 m Shuttle Run, 20-m Shuttle Run Test. First, each school was contacted to obtain the approval of the director and the school board. None of the schools invited refused to participate. Subsequently, newsletters explaining the objectives of the study, and requesting written consent for students’ participation, were sent to the parents of the selected students. The design of the study was conducted under the principles established in the Declaration of Helsinki, and information management was conducted according to the provisions laid forth in Spanish law (Law 15/1999 of 13 December on the Protection of Personal Data). Data Analysis The adjustment to normal distribution of the different variables was evaluated both by graphs and by the Kolmogorov-Smirnov test. Fitness levels by age (years) and sex were presented as mean and standard deviation. Sex differences on fitness levels were tested by using Student-t statistic. To provide smoothed centile curves (P10 , P25 , P50 , P75 , and P90 ) for schoolchildren, physical fitness data were analyzed by maximum penalized likelihood
METHODS Participants This is a multicenter, cross-sectional observational study including 1725 both sexes, aged 6-12 years, primary schoolchildren from 75 public and private 626
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using the LMS statistical method by sex and age19,20 (LmsChartMaker software V. 2.3; by Tim Cole and Huiqi Pan). The LMS method does not work with 0 values. Because a number of schoolchildren scored 0 in the bent arm hang test, we estimated centile values for this test using standard procedures instead of the LMS method. The cardiovascular risk associated with low CRF for children was calculated using the new cutoff points proposed in 2010 by the Cooper Institute’s FITNESSGRAM group.17,18 Only subjects in the range of 10-12 years old were taken into account for this calculation, since there are no standards for subjects younger than 10 years of age. We used the statistical chi-square to determine the existence of differences by sex in the prevalence of cardiovascular risk associated with low CRF. IBM SPSS 19 Statistics software was used, except in the LMS method calculations, and the significance level was set at p ≤ .05.
RESULTS Table 1 shows the results of the physical fitness tests by age and sex. Boys scored higher than girls in all the fitness tests, except in the flexibility test. Overall, the mean scores for the physical fitness variables increase with age for boys and girls, except for flexibility, which decreases in boys and remains stable in girls, and the levels of VO2max (mL/kg/minutes) which decrease in both sexes. The smoothed centile curves (P10 , P25 , P50 , P75 , and P90 ) for different fitness tests for both sexes, by age, were in the same direction as in Table 1 (Figures 1-3). Figure 4 depicts the smoothed centile curves (P10 , P50 , and P90 ) of the main components of physical fitness in Spanish, Latvian, and Australian children, by sex and age. In general, Latvian and Australian schoolchildren scored higher than Spanish children in P90 . In P50 and P10 , fitness tests figures were similar to those of Latvian children; however, Spanish children scored lower in strength and flexibility, in both sexes, compared with their Australian counterparts. Cardiovascular risk associated with their current CRF was 26% for girls (5% higher risk, 21% some risk) and 13% for boys (2.8% higher risk, 10.2% some risk).
DISCUSSION This study provides, through smoothed centiles, updated values for different tests of physical fitness in schoolchildren aged 6 to 12, from Castilla-La Mancha, Spain. In our study, boys show better values of physical fitness than girls in all components of fitness, except for flexibility. As age increases, students improve in all the fitness levels, except for flexibility Journal of School Health
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and VO2max (mL/kg/minutes). Older boys show less flexibility levels than younger; in girls, after puberty the flexibility levels are stable. In both, boys and girls, VO2max (mL/kg/minutes) values declined with age (Figures 1-3). As in other national,21 European,13,22-24 and international studies,25,26 boys showed higher levels of fitness than girls, except for flexibility. It has been reported that, before puberty, differences in fitness between sexes are absent or negligible;27-30 however, other studies have found that these sex differences could be due to morphological characteristics (different somatotype)31 and physiological traits (eg, differences in mechanical efficiency and/or fractional utilization).32 In our study, as in others,22,25,26 musculoskeletal, respiratory, and motor abilities increased with age during the school-age years (Figures 1 and 3). It seems paradoxical, however, that in the case of VO2max (mL/kg/minutes), calculated from the data gathered from the 20-m shuttle run test, the younger schoolchildren of our study showed the highest levels (Table 1 and Figure 2). In our opinion, the reason for these unexpected results is that although the absolute VO2max (mL) increases with age,27,33 the increase in adiposity is responsible for the decrease in VO2max , expressed in relation to body weight. This has been observed in Spanish subjects of this age group,34 as well as described in other studies.32,35 The decline or stability of flexibility found in the children of our study (Figure 2) has been described in other studies,13,22,25,26 and is not surprising because flexibility, if not specifically maintained, diminishes with age.36 Upon comparing our data with those taken from Australian and Latvian schoolchildren, it was striking to see that Spanish students show lower fitness levels in the highest categories (P90 ); in other words, when looking at those children who performed highest, Spanish schoolchildren score worse on all the tests, by age and sex, than their Australian and Latvian counterparts. For all other centiles (P50 and P10 ), our data are similar to those observed in Latvian children.13 Compared to data taken from Australian children, Spanish children show lower muscle strength and flexibility, with the differences between the countries more pronounced in boys.25 Because it is unlikely that substantial genetic differences exist between our sample and Australian and Latvian children, it is probable that differences in physical activity explain the lower physical fitness values that we observed. In one study describing physical activity patterns in Spanish children of 9 years of age, boys were shown to perform an average of 81.8 minutes/day of moderate-vigorous physical activity (MVPA), and girls an average of 57.51 minutes/day.37 Meanwhile, in Australia,
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© 2014, American School Health Association 11.6± 6.2 12.7± 5.9 15± 5.4 16± 5.4 16.4± 6 18.4± 5.3 19.4± 4.4
3.8± 4.2 4.5± 4.7 5.6± 6.6 5.5± 5.2 4.5± 5.9 6.4± 6.9 7± 8.2
9.5± 2.2 10.8± 2.5 12.5± 2.8 14.1± 2.9 16± 3.6 19± 4.2 21.5± 4.4
10.2± 2.5 12.1± 2.8** 13.9± 2.5** 15.7± 3.6** 17.1± 3.9* 18.8± 4 22.8± 5.6
Handgrip Test (kg)
Maximal Strength
95.3± 19.2 100.4± 14.9 111.7± 16.6 113.2± 17.9 118.8± 19.5 129± 21.2 132± 24.4
106.5± 16.3** 113.6± 19.1** 122.4± 17.9** 125.1± 20.5** 131± 18.3** 141.4± 23.5** 148.9± 25.6**
Broad Jump Test (cm)
Explosive Strength
18.6± 6* 17.6± 5.6* 18± 5.9** 16.7± 6.7 17.8± 7** 17.3± 6.8** 19± 7.1**
16.3± 5.1 16.2± 5.2 15.2± 5.3 15.3± 6.5 12.8± 6.5 13.3± 6.1 12.5± 6.9
Sit and Reach Test (cm)
Flexibility
1.5± 0.7 2± 1 2.3± 1.3 2.3± 1.3 2.8± 1.4 3.1± 1.5 3.8± 1.7
2.1± 1.3** 2.5± 1.4* 3± 1.9* 3.5± 2** 3.8± 1.9** 4.5± 2.1** 5.1± 2.1**
(stage)
47.9± 1.5 47.1± 2.1 46± 2.8 44.2± 3 43.3± 3.4 42.3± 3.8 42.4± 4.3
49.3± 2.8** 48.2± 3.1* 47.4± 4.3* 46.8± 4.6** 45.9± 4.5** 45.9± 5.3** 45.7± 5.4**
VO2max (mL/kg/ minutes)†
Cardiorespiratory Endurance (20 m Endurance Shuttle Run Test)
*Mean differences by sex statistically significant (p ≤ .05). **Mean differences by sex statistically significant (p ≤ .001). † VO 2max , maximal oxygen consumption, calculated as: VO2max = 31.025 + 3.238S − 3.248A + 0.1536SA, where A, age; S, final speed (8 + 0.5× last stage completed). ‡ Lower values indicate better performance.
12.3± 6.1 14.9± 6.1* 16.7± 5.9* 18± 5.5* 19.7± 5** 20.5± 5.7* 21.9± 6.5*
Sit-Ups Test (Repeats)
5.6± 6.5* 6.6± 7* 8± 8.7* 8.4± 8.6* 9.6± 10.8** 10.4± 10** 11.8± 11.6*
Bent Arm Hang Test (s)
Boys (N= 868) 6 7 8 9 10 11 12 Girls (N= 857) 6 7 8 9 10 11 12
Age (Years)
Muscular Endurance
Muscular Strength
Table 1. Physical Fitness Scores (Mean ± SD) of EUROFIT Battery for Spanish Schoolchildren by Age and Sex
26.2± 3.1 25± 2.3 24.1± 2.8 23.9± 2.4 23.3± 2.8 22.5± 2.4 22.3± 2.3
25.2± 3** 24± 3.5* 23± 2.5* 22.5± 2.3** 21.8± 2.3** 21.4± 2.3** 21± 3.2**
Shuttle Run Test (10 × 5) (seconds)‡
Total Body Balance
23.1± 4.1 21± 3.6 18.3± 2.9 17.3± 2.9 15.6± 2.4 14.3± 1.9 13.4± 1.9
22.9± 3.9 20.5± 3.6 18.3± 3.1 17.1± 2.8 15.7± 2.5 14.7± 2.3 14± 2.3*
19.3± 6.3 13.8± 7.1 12.2± 7.6 11.6± 6.8 10.5± 7.8 8.7± 6.3 9.4± 7
20.3± 6.6 17.1± 7.6* 14.8± 7* 13.1± 7.4 11.4± 7.7 9.3± 6.7 9.5± 6.3
Plate Tapping Flamingo Test Test (seconds)‡ (no falls)‡
Speed
Figure 1. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Bent Arm Hang (s), (b) Sit-Up Test (repetitions), (c) Handgrip Test (kg), and (d) Broad Jump Test (cm)
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Figure 2. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Sit and Reach Test (cm), (b) 20-m Shuttle Run (min), and (c) 20-m Shuttle Run (mL/kg/minutes)
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127.1 minutes/day is the average for boys and 100.9 minutes/day for girls.38 Similarly, the HBSC (Health Behaviors in School-aged Children) study in children aged 11 to 15 described that 54% of Latvian boys and 40% of Latvian girls performed 1 hour/day 630 •
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of MVPA, 5 days a week, compared to 46% of boys and 34% of girls in Spain.39 Our study can inform the physical fitness levels in schoolchildren (ages 6 to 12) from the center of Spain, and estimates the corresponding smoothed centiles •
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Figure 3. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Shuttle Run Test (10 × 5) (s), (b) Plate Tapping Test (s), and (c) Flamingo Test (Number of Falls). *Lower scores indicate better performance
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according to age and sex (Figures 1-3) that could be used as reference values to identify children with low fitness at school. According to other authors,10 falling below the lowest decile (P10 ) should be considered as a warning signal. In terms of population, having a fitness level below the 5th centile is usually considered an indicator of future cardiovascular risk.40,41 Other authors establish 5 risk categories based on the quintile in which one’s Journal of School Health
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fitness level lies.9 From a clinical point of view, it is more useful to establish fitness categories that are associated with future cardiovascular risk, such as those proposed by the Cooper Institute through data obtained from the FITNESSGRAM program. With those data, 2 categories, or ‘‘zones’’ were established, according to aerobic capacity: a Needs Improvement Zone (NIZ)—further divided into ‘‘some risk’’ and ‘‘high risk’’—and a Healthy Fitness Zone (HFZ).
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Figure 4. Physical Fitness Centile Curves (P10 , P50 , and P90 ) of 6 EUROFIT Tests From This Study (Castilla-La Mancha, Spain; CLM) and From 2 Countries (AUS, Australia and LAT, Latvia). *Lower scores indicate better performance Trunk strength-Sit-up test (a)
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Considering jointly the NIZ areas, 26% of girls and 13% of boys ages 10-12 from our study are at levels of aerobic capacity associated with future cardiovascular risk. We observe that the percentage of girls that show future cardiovascular risk is twice that of boys, whereas maintaining this relationship in the 2 risk subzones. According to these data, 1 in 4 girls and 1 in 10 boys have a high likelihood of cardiovascular disease in adulthood if their CRF does not improve. Our data are similar to those found in American children who, when the new FITNESSGRAM cutoff points were used, showed that 27.2% of girls and 19% of boys have cardiovascular risk associated with low CRF.17 Our data are also similar to those found in Portugal, where 28.3% of girls and 18.5% of boys showed cardiovascular risk associated with low CFR, according to the Cooper Institute criteria of 1999.42 Our data contrast with those of the EYHS (European Youth Heart Study), in which more than 40% of Swedish and Estonian schoolchildren aged 9 to 10 had levels of aerobic capacity associated with cardiovascular risk.43 In view of the low prevalence of overweight, and the high levels of physical activity of Swedish and Estonian children,44,45 the estimates of low aerobic capacity reported in the EYHS are surprising. We believe that, in addition to the fact that different cutoff points were used in the EYHS, these differences in the estimates of the prevalence of NIZ could be attributed to differences in the methodology used for estimating ´ equation using data VO2max . In our study, Leger’s from the 20-m shuttle run test was used for the indirect estimation of VO2max , whereas in the EYHS was directly assessed by means of a maximal cycle ergometer fitness test. To our knowledge, there are no prevalence data of cardiovascular risk associated with low CRF in Spanish children aged 10-12 using the new ´ et al30 working criteria of Cooper Institute.46 Casajus with children in Aragon, a region of northern Spain, reported that 9.1% of boys and 4.8% of girls do not reach the minimum levels recommended for healthy cardiovascular fitness. These percentages are clearly lower than those reported in our study. One possible explanation lies in the use of different cutoff points to categorize children at risk of future cardiovascular disease: 42 and 38 mL/kg/minutes for boys and girls respectively vs, in our study, 37.3 mL/kg/minutes for boys and girls aged 10-11, and 37.6 mL/kg/minutes for boys aged 12 and 37.0 mL/kg/minutes for girls aged 12. In the HELENA study, a European study including adolescents from 9 countries, 39% of boys and 43% of girls had high probability of future cardiovascular disease because of low CRF.10 These high figures during adolescence coincide with the gradual abandonment of physical/athletic activity that occurs among schoolchildren with the arrival of adolescence, which may explain the differences between children and adolescents. Journal of School Health
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Limitations One of the major limitations of this study is that it includes children from only a single region of Spain; therefore, inferences to all Spanish children should be made cautiously. However, the sample size, the inclusion of both rural and urban schools, and the similarity between fitness values found in our study and those found in other studies conducted in different geographical areas of Spain,21,30,47,48 all suggest that our data may be representative of the set of Spanish children aged 6-12. However, because our study is a cross-sectional one, it may be that a cohort effect has occurred, and as a consequence, our estimations of fitness levels could not be extrapolated to previous cohorts. Finally, a decrease in the prevalence of overweight in Spanish schoolchildren would likely improve CRF in terms of VO2max (mL/kg/minutes), and thus lower future cardiovascular risk. Conclusions Our study shows the physical health levels of Spanish schoolchildren aged 6-12 of Castilla-La Mancha, Spain, which could be useful in identifying children with low fitness and developing strategies to improve it. The physical fitness of Spanish children is worse than that of children from other countries. Within Spain, 1 in 4 girls and 1 in 10 boys has a level of CRF indicative of future cardiovascular risk. The high prevalence of cardiovascular risk associated with low aerobic capacity and low levels of strength compared with other countries in our study highlights the need to make deliberate, carefully planned efforts in the Spanish schools to improve the physical fitness of schoolchildren.
IMPLICATIONS FOR SCHOOL HEALTH With 1 in 5 schoolchildren exhibiting aerobic capacity levels associated with future cardiovascular risk, Spanish schoolchildren are less physically fit than their counterparts outside Spain. It has been suggested that these alarming figures are associated with low levels of physical activity in the population.37 Because of the relationships between fitness and cardiovascular risk,49 and between physical exercise and fitness50 that have been described, it is necessary to implement physical activity programs focused on the improvement of aerobic capacity and muscular strength. Such programs would obviously require collaboration among schools, health workers, politicians, and families. Schools are places where children spend a large amount of time, and thus, function as a setting in which to implement interventions to fight against sedentariness in infancy and, as a consequence, against cardiovascular disease in the coming years. Several strategies for promoting physical activity on schools
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have demonstrated some effectiveness in improving cardiometabolic health;51 thus, the challenge at this moment is to implement these interventions in an environment of economic crisis, even if they have a proven acceptable cost effectiveness ratio.52 In Spain, this challenge has a pivotal role as 2 circumstances converge: first, the time allocated to physical exercise is declining in the school schedules, and second, the prevalence of sedentary behavior during leisure time is increasing. To promote changes in students’ lifestyles, education and health authorities need to work with school directors to evaluate the implementation of physical activity programs of moderate to vigorous intensity, which could take place during a recess or before or after school hours. These programs should include recreational activities, sports, dancing, and outdoor activities. It would be desirable for these programs to include interventions that reach beyond the school to improve other aspects of a healthy lifestyle, such as eating habits or commuting behavior.53 We have gathered values for the health-related physical fitness of children aged 6-12 in Castilla-La Mancha, Spain. These values can be used both to assess students’ fitness levels and to detect the students whose fitness levels are below a healthy minimum.
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12. 13.
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Human Subjects Approval Statement The study was approved by the Ministry of Education and Science of the Regional Government of Castilla-La Mancha, and the Faculty of Education at the University of Castilla-La Mancha, Spain. All parents or guardians of the subjects participating in the study signed informed consent forms to participate in the study.
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adulthood: the Northern Ireland Young Hearts Project. Int J Sports Med. 2002;23(suppl 1):S22-S26. Cleland VJ, Ball K, Magnussen C, Dwyer T, Venn A. Socioeconomic position and the tracking of physical activity and cardiorespiratory fitness from childhood to adulthood. Am J Epidemiol. 2009;170(9):1069-1077. Andersen LB, Hasselstrom H, Gronfeldt V, Hansen SE, Karsten F. The relationship between physical fitness and clustered risk, and tracking of clustered risk from adolescence to young adulthood: eight years follow-up in the Danish Youth and Sport Study. Int J Behav Nutr Phys Act. 2004;1(1):6. Ortega FB, Ruiz JR, Castillo MJ, et al. Low level of physical fitness in Spanish adolescents. Relevance for future cardiovascular health (AVENA study). Rev Esp Cardiol. 2005;58(8):898-909. Ortega FB, Artero EG, Ruiz JR, et al. Physical fitness levels among European adolescents: the HELENA study. Br J Sports Med. 2011;45(1):20-29. Research CES. EUROFIT: Handbook for the EUROFIT Tests of Physical Fitness. 2nd ed. Strasbourg, France: Committee of Experts on Sports Research; 1993. Deporte IdCdlEFye. EUROFIT. TEST EUROPEO DE APTITUD ´ y Ciencia; 1992. FI´SICA. Madrid, Spain: Ministerio de Educacion Sauka M, Priedite IS, Artjuhova L, et al. Physical fitness in northern European youth: reference values from the Latvian Physical Health in Youth Study. Scand J Public Health. 2011;39(1):35-43. EUROFIT. Handbook for the EUROFIT Tests of Physical Fitness. Rome, Italy: Council of Europe; 1988. Meredith MD, Welk G. FITNESSGRAM/ACTIVITYGRAM: Test Administration Manual. 4th ed. Champaign, IL: Human Kinetics; 2007. Meredith MD, Welk G. FITNESSGRAM/ACTIVITYGRAM: Test Administration Manual. 3rd ed. Champaign, IL: Human Kinetics; 2004. Welk GJ, De Saint-Maurice Maduro PF, Laurson KR, Brown DD. Field evaluation of the new FITNESSGRAM(R) criterionreferenced standards. Am J Prev Med. 2011;41(4 suppl 2):S131S142. Welk GJ, Laurson KR, Eisenmann JC, Cureton KJ. Development of youth aerobic-capacity standards using receiver operating characteristic curves. Am J Prev Med. 2011;41(4 Suppl 2):S111S116. Cole TJ, Green PJ. Smoothing reference centile curves: the LMS method and penalized likelihood. Stat Med. 1992;11(10):13051319. Cole TJ, Freeman JV, Preece MA. British 1990 growth reference centiles for weight, height, body mass index and head circumference fitted by maximum penalized likelihood. Stat Med. 1998;17(4):407-429. Chillon P, Ortega FB, Ferrando JA, Casajus JA. Physical fitness in rural and urban children and adolescents from Spain. J Sci Med Sport. 2011;14(5):417-423. Woll A, Kurth BM, Opper E, Worth A, Bos K. The ‘MotorikModul’ (MoMo): physical fitness and physical activity in German children and adolescents. Eur J Pediatr. 2011;170(9): 1129-1142. Sacchetti R, Ceciliani A, Garulli A, et al. Physical fitness of primary school children in relation to overweight prevalence and physical activity habits. J Sports Sci. 2012;30(7):633-640. Volbekiene V, Griciute A. Health-related physical fitness among schoolchildren in Lithuania: a comparison from 1992 to 2002. Scand J Public Health. 2007;35(3):235-242. Catley MJ, Tomkinson GR. Normative health-related fitness values for children: analysis of 85347 test results on 9-17-yearold Australians since 1985. Br J Sports Med. 2013;47(2):98-108. Armstrong ME, Lambert EV, Lambert MI. Physical fitness of South African primary school children, 6 to 13 years of age: discovery vitality health of the nation study. Percept Mot Skills. 2011;113(3):999-1016.
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27. Malina RM, Bouchard C, Bar-Or O. Growth, Maturation, and Physical Activity. 2nd ed. Champaign, IL: Human Kinetics; 2004. 28. Haywood K, Getchell N. Life Span Motor Development. 3rd ed. Champaign, IL: Human Kinetics; 2001. 29. Davies PL, Rose JD. Motor skills of typically developing adolescents: awkwardness or improvement? Phys Occup Ther Pediatr. 2000;20(1):19-42. ´ JA, Ortega FB, Vicente-Rodr´ıguez G, Leiva MT, Moreno 30. Casajus LA, Ara I. Physical fitness, fat distribution and health in schoolage children (7 to 12 years). Rev Int Med Cienc Act F´ıs Deporte. 2012;12(47):523-537. 31. Marta CC, Marinho DA, Barbosa TM, Izquierdo M, Marques MC. Physical fitness differences between prepubescent boys and girls. J Strength Cond Res. 2012;26(7):1756-1766. 32. Rowland TW. Evolution of maximal oxygen uptake in children. Med Sport Sci. 2007;50:200-209. 33. Armstrong N, Williams J, Balding J, Gentle P, Kirby B. The peak oxygen uptake of British children with reference to age, sex and sexual maturity. Eur J Appl Physiol Occup Physiol. 1991;62(5):369375. 34. Martinez-Vizcaino V, Solera Martinez M, Notario Pacheco B, et al. Trends in excess of weight, underweight and adiposity among Spanish children from 2004 to 2010: the Cuenca study. Public Health Nutr. 2012;15(12):2170-2174. 35. Dencker M, Thorsson O, Karlsson MK, et al. Gender differences and determinants of aerobic fitness in children aged 8-11 years. Eur J Appl Physiol. 2007;99(1):19-26. 36. Alter MJ. Science of Flexibility. 3 ed. Champaign, IL: Human Kinetics; 2004. 37. Aznar S, Naylor PJ, Silva P, et al. Patterns of physical activity in Spanish children: a descriptive pilot study. Child Care Health Dev. 2011;37(3):322-328. 38. Dollman J, Maher C, Olds TS, Ridley K. Physical activity and screen time behaviour in metropolitan, regional and rural adolescents: a sectional study of Australians aged 9-16 years. J Sci Med Sport. 2012;15(1):32-37. 39. Haug E, Rasmussen M, Samdal O, et al. Overweight in schoolaged children and its relationship with demographic and lifestyle factors: results from the WHO-Collaborative Health Behaviour in School-aged Children (HBSC) study. Int J Public Health. 2009;54(suppl 2):167-179. 40. Hasselstrom H, Hansen SE, Froberg K, Andersen LB. Physical fitness and physical activity during adolescence as predictors of cardiovascular disease risk in young adulthood. Danish Youth and Sports Study An Eight-year Follow-up Study. Int J Sports Med. 2002;23(suppl 1):S27-S31. 41. Twisk JW, Kemper HC, van Mechelen W. Prediction of cardiovascular disease risk factors later in life by physical
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activity and physical fitness in youth: general comments and conclusions. Int J Sports Med. 2002;23(suppl 1):S44-S49. Mota J, Flores L, Ribeiro JC, Santos MP. Relationship of single measures of cardiorespiratory fitness and obesity in young schoolchildren. Am J Hum Biol. 2006;18(3):335-341. Ruiz JR, Ortega FB, Rizzo NS, et al. High cardiovascular fitness is associated with low metabolic risk score in children: the European Youth Heart Study. Pediatr Res. 2007;61(3):350-355. Ortega FB, Ruiz JR, Sjostrom M. Physical activity, overweight and central adiposity in Swedish children and adolescents: the European Youth Heart Study. Int J Behav Nutr Phys Act. 2007;4:61. Ekelund U, Sardinha LB, Anderssen SA, et al. Associations between objectively assessed physical activity and indicators of body fatness in 9- to 10-y-old European children: a populationbased study from 4 distinct regions in Europe (the European Youth Heart Study). Am J Clin Nutr. 2004;80(3):584-590. Meredith MD, Welk G. Cooper Institute (Dallas Tex.). FITNESSGRAM & ACTIVITYGRAM: Test Administration Manual. 4th ed. Champaign, IL: Human Kinetics; 2010. Castro-Pineiro J, Ortega FB, Keating XD, Gonzalez-Montesinos JL, Sjostrom M, Ruiz JR. Percentile values for aerobic performance running/walking field tests in children aged 6 to 17 years: influence of weight status. Nutr Hosp. 2011;26(3):572578. Castro-Pinero J, Gonzalez-Montesinos JL, Mora J, et al. Percentile values for muscular strength field tests in children aged 6 to 17 years: influence of weight status. J Strength Cond Res. 2009;23(8):2295-2310. Anderssen SA, Cooper AR, Riddoch C, et al. Low cardiorespiratory fitness is a strong predictor for clustering of cardiovascular disease risk factors in children independent of country, age and sex. Eur J Cardiovasc Prev Rehabil. 2007;14(4):526-531. Armstrong N, Tomkinson G, Ekelund U. Aerobic fitness and its relationship to sport, exercise training and habitual physical activity during youth. Br J Sports Med. 2011;45(11):849-858. Martinez Vizcaino V, Salcedo Aguilar F, Franquelo Gutierrez R, et al. Assessment of an after-school physical activity program to prevent obesity among 9- to 10-year-old children: a cluster randomized trial. Int J Obes (Lond). 2008;32(1):12-22. Moya Martinez P, Sanchez Lopez M, Lopez Bastida J, et al. Cost-effectiveness of an intervention to reduce overweight and obesity in 9-10-year-olds. The Cuenca study. Gac Sanit. 2011;25(3):198-204. Chillon P, Ortega FB, Ruiz JR, et al. Active commuting to school in children and adolescents: an opportunity to increase physical activity and fitness. Scand J Public Health. 2010;38(8): 873-879.
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Physical Fitness in Spanish Schoolchildren Aged 6-12 Years: Reference Values of the Battery EUROFIT and Associated Cardiovascular Risk ´ ´ ´ ROBERTO GUL´ıAS-GONZALEZ , PhDa MAIRENA SANCHEZ -LOPEZ , PhDb A´ NGEL OLIVAS-BRAVO, BSci Edc MONTSERRAT SOLERA-MART´ıNEZ, PhDd VICENTE MART´ıNEZ-VIZCA´ıNO, MD, PhDe
ABSTRACT BACKGROUND: Physical fitness is considered an important indicator of health in children. The aims of this study were to (1) provide sex- and age-specific EUROFIT battery levels of fitness in Spanish children; (2) compare Spanish children’s fitness levels with those of children from other countries; and (3) determine the percentage of Spanish children with cardiovascular risk associated with low cardiorespiratory fitness (CRF). METHODS: Physical fitness was assessed using the EUROFIT tests in 1725 children, aged 6 to 12, from Castilla-La Mancha, Spain. We derived specific values for physical fitness using LMS method. FITNESSGRAM 2010 criteria were used to estimate the percentage of children with cardiovascular risk associated with low CRF. RESULTS: Boys scored higher in all the physical fitness tests, except for the flexibility test. Physical fitness improved as age increased, except for flexibility, which worsened in boys, and VO2max, which decreased in both sexes. The prevalence of boys and girls with cardiovascular risk associated to low CRF was 13% and 26%, respectively. CONCLUSIONS: Specific fitness test scores for children and adolescents can represent the fitness status of schoolchildren accurately. Schools need to make efforts to improve the fitness level of the schoolchildren to prevent cardiovascular risk. Keywords: child and adolescent health; physical fitness and sport; public health. ´ Solera-Mart´ınez M, Mart´ınez-Vizca´ıno V. Physical fitness in Citation: Gul´ıas-Gonz´alez R, S´anchez-L´opez M, Olivas-Bravo A, Spanish schoolchildren aged 6-12 years: reference values of the battery EUROFIT and associated cardiovascular risk. J Sch Health. 2014; 84: 625-635. Received on October 25, 2012 Accepted on January 5, 2014
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hysical fitness is considered an important indicator of health in children and adolescents.1,2 High levels of cardiorespiratory fitness (CRF) in childhood are associated with increased cardiovascular, skeletal, and mental health,1,2 and improvements in muscular strength levels from childhood to adolescence are
associated with a decrease in total adiposity.2 Although less studied, speed/agility is strongly related to bone mineral density and bone mass accumulation in later stages of life.2-4 Low levels of physical fitness in childhood are associated with an increased risk of cardiovascular disease in adulthood.3-5 Furthermore,
a
Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. c Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain. d Assistant Professor, ([email protected]), Social and Health Care Research Center; University of Castilla-La Mancha, Santa Teresa Jornet s/n, 16071 Cuenca, Spain. e Professor, ([email protected]), Social and Health Care Research Center, University of Castilla-La Mancha, Santa Teresa Jornet s/n, 16071 Cuenca, Spain. b
Address correspondence to: Roberto Gul´ıas-Gonz´alez, Assistant Professor, ([email protected]), Faculty of Education, University of Castilla-La Mancha, Ronda de Calatrava, 3, 13071 Ciudad Real, Spain The authors of this study express their appreciation and gratitude to all the schools, students, and teachers who participated in this study voluntarily. Also to all members involved in the fieldwork for their effort and enthusiasm. This study was funded by the Ministry of Education and Science through aid for the development of cooperation projects in the field of innovation and research among the faculty and nonuniversity teachers of the autonomous community of Castilla-La Mancha, Spain (Resolution 08/07/2009, the Deputy Ministry of Education of the Regional Government of Castilla-La Mancha). Data about physical fitness smoothed centile values for the EUROFIT battery of tests by sex and age in the schoolchildren are available from the corresponding author.
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the level of physical fitness in childhood is a predictor of physical fitness in adult life;2,5-8 therefore, to include measurements of physical fitness related to health in the education and health systems is clearly justified. In Spain, the main drivers behind the alarming trend of obesity prevalence in schoolchildren are richly debated. A possible way to try to clarify this issue is to compare the fitness levels of Spanish children with those of children in other countries where the prevalence of obesity is appreciably lower. Considering the consistently described relationship between daily physical activity and fitness levels, if the levels of fitness of Spanish children are lower than the levels in countries with lower obesity prevalence, such as northern European countries, the sedentary lifestyle could be considered as the main driver of the current obesity epidemic. To assess physical fitness, updated values for the target population are necessary. Owing to methodological differences in the protocols of assessment of physical fitness, comparing and interpreting the results between and among different population studies is complicated.9,10 EUROFIT battery has proven to be a simple, standardized, and practical instrument, with good reliability and validity.11-14 Traditionally, the program FITNESSGRAM has provided valid and reliable cutoff points for identifying children with future cardiovascular risk according to their level of CRF.15,16 However, improved standards developed with advanced statistical techniques (Receiver Operating Characteristic-ROC-curves) have recently been published. These new criteria allow the categorization of children into 3 fitness levels (Healthy Fitness Zone, Higher Risk, and Some Risk), thereby providing more specific and clearer information than the previous 2 categories (Healthy Fitness Zone and Needs Improvement Zone) established by traditional standards.17,18 Placing individuals and groups in percentiles and categories allow to identify individuals with low fitness levels and to implement interventions to promote healthy behaviors in order to prevent future cardiovascular risk. This study aimed to (1) assess the physical fitness of children, aged 6-12, from Castilla-La Mancha, Spain, according to sex and age; (2) compare our results with those of other European and international studies conducted in the same population group; and (3) estimate the prevalence of students who present future cardiovascular risk associated with low CRF, in schoolchildren aged 10-12 in Castilla-La Mancha, Spain.
schools randomly selected from the 778 schools in Castilla-La Mancha by multistage sampling. In each school, 2 boys and 2 girls were randomly selected per class, 1st to 6th grades. A sample size of 629 subjects was estimated by using EpiData 3.1 software (EpiData Association, Odense, Denmark), considering a prevalence of cardiovascular risk associated with low CRF of 18%,9 a confidence level of 95%, and 3% accuracy. Because we intended to maintain that accuracy in both sexes, and considering a nonresponse rate of 30%, the minimum sample size was estimated in 1635 students. Data from 2 population-based samples (Latvia and Australia) were used to compare data from Spanish students with data belonging to other countries. These samples were selected because of both of them employed the same fitness tests used in our study, and were also large samples from the same age range. Instruments and Procedure Measurements were carried out on the premises of each school between April and May 2010. Tests were carried out by researchers with Bachelor of Science degrees in physical activity and education, and by physical education teachers who had previously completed a 2-day training course to standardize measurements. Evaluation of physical fitness. In the gymnasium of each school, physical fitness was assessed using the 9 tests included in the EUROFIT battery:11,12 Flamingo Balance Test, Plate Tapping, Sit and Reach Test, Standing Broad Jump Test, Handgrip Test, Sit-ups in 30 seconds, Bent Arm Hang, 10 × 5 m Shuttle Run, 20-m Shuttle Run Test. First, each school was contacted to obtain the approval of the director and the school board. None of the schools invited refused to participate. Subsequently, newsletters explaining the objectives of the study, and requesting written consent for students’ participation, were sent to the parents of the selected students. The design of the study was conducted under the principles established in the Declaration of Helsinki, and information management was conducted according to the provisions laid forth in Spanish law (Law 15/1999 of 13 December on the Protection of Personal Data). Data Analysis The adjustment to normal distribution of the different variables was evaluated both by graphs and by the Kolmogorov-Smirnov test. Fitness levels by age (years) and sex were presented as mean and standard deviation. Sex differences on fitness levels were tested by using Student-t statistic. To provide smoothed centile curves (P10 , P25 , P50 , P75 , and P90 ) for schoolchildren, physical fitness data were analyzed by maximum penalized likelihood
METHODS Participants This is a multicenter, cross-sectional observational study including 1725 both sexes, aged 6-12 years, primary schoolchildren from 75 public and private 626
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using the LMS statistical method by sex and age19,20 (LmsChartMaker software V. 2.3; by Tim Cole and Huiqi Pan). The LMS method does not work with 0 values. Because a number of schoolchildren scored 0 in the bent arm hang test, we estimated centile values for this test using standard procedures instead of the LMS method. The cardiovascular risk associated with low CRF for children was calculated using the new cutoff points proposed in 2010 by the Cooper Institute’s FITNESSGRAM group.17,18 Only subjects in the range of 10-12 years old were taken into account for this calculation, since there are no standards for subjects younger than 10 years of age. We used the statistical chi-square to determine the existence of differences by sex in the prevalence of cardiovascular risk associated with low CRF. IBM SPSS 19 Statistics software was used, except in the LMS method calculations, and the significance level was set at p ≤ .05.
RESULTS Table 1 shows the results of the physical fitness tests by age and sex. Boys scored higher than girls in all the fitness tests, except in the flexibility test. Overall, the mean scores for the physical fitness variables increase with age for boys and girls, except for flexibility, which decreases in boys and remains stable in girls, and the levels of VO2max (mL/kg/minutes) which decrease in both sexes. The smoothed centile curves (P10 , P25 , P50 , P75 , and P90 ) for different fitness tests for both sexes, by age, were in the same direction as in Table 1 (Figures 1-3). Figure 4 depicts the smoothed centile curves (P10 , P50 , and P90 ) of the main components of physical fitness in Spanish, Latvian, and Australian children, by sex and age. In general, Latvian and Australian schoolchildren scored higher than Spanish children in P90 . In P50 and P10 , fitness tests figures were similar to those of Latvian children; however, Spanish children scored lower in strength and flexibility, in both sexes, compared with their Australian counterparts. Cardiovascular risk associated with their current CRF was 26% for girls (5% higher risk, 21% some risk) and 13% for boys (2.8% higher risk, 10.2% some risk).
DISCUSSION This study provides, through smoothed centiles, updated values for different tests of physical fitness in schoolchildren aged 6 to 12, from Castilla-La Mancha, Spain. In our study, boys show better values of physical fitness than girls in all components of fitness, except for flexibility. As age increases, students improve in all the fitness levels, except for flexibility Journal of School Health
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and VO2max (mL/kg/minutes). Older boys show less flexibility levels than younger; in girls, after puberty the flexibility levels are stable. In both, boys and girls, VO2max (mL/kg/minutes) values declined with age (Figures 1-3). As in other national,21 European,13,22-24 and international studies,25,26 boys showed higher levels of fitness than girls, except for flexibility. It has been reported that, before puberty, differences in fitness between sexes are absent or negligible;27-30 however, other studies have found that these sex differences could be due to morphological characteristics (different somatotype)31 and physiological traits (eg, differences in mechanical efficiency and/or fractional utilization).32 In our study, as in others,22,25,26 musculoskeletal, respiratory, and motor abilities increased with age during the school-age years (Figures 1 and 3). It seems paradoxical, however, that in the case of VO2max (mL/kg/minutes), calculated from the data gathered from the 20-m shuttle run test, the younger schoolchildren of our study showed the highest levels (Table 1 and Figure 2). In our opinion, the reason for these unexpected results is that although the absolute VO2max (mL) increases with age,27,33 the increase in adiposity is responsible for the decrease in VO2max , expressed in relation to body weight. This has been observed in Spanish subjects of this age group,34 as well as described in other studies.32,35 The decline or stability of flexibility found in the children of our study (Figure 2) has been described in other studies,13,22,25,26 and is not surprising because flexibility, if not specifically maintained, diminishes with age.36 Upon comparing our data with those taken from Australian and Latvian schoolchildren, it was striking to see that Spanish students show lower fitness levels in the highest categories (P90 ); in other words, when looking at those children who performed highest, Spanish schoolchildren score worse on all the tests, by age and sex, than their Australian and Latvian counterparts. For all other centiles (P50 and P10 ), our data are similar to those observed in Latvian children.13 Compared to data taken from Australian children, Spanish children show lower muscle strength and flexibility, with the differences between the countries more pronounced in boys.25 Because it is unlikely that substantial genetic differences exist between our sample and Australian and Latvian children, it is probable that differences in physical activity explain the lower physical fitness values that we observed. In one study describing physical activity patterns in Spanish children of 9 years of age, boys were shown to perform an average of 81.8 minutes/day of moderate-vigorous physical activity (MVPA), and girls an average of 57.51 minutes/day.37 Meanwhile, in Australia,
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© 2014, American School Health Association 11.6± 6.2 12.7± 5.9 15± 5.4 16± 5.4 16.4± 6 18.4± 5.3 19.4± 4.4
3.8± 4.2 4.5± 4.7 5.6± 6.6 5.5± 5.2 4.5± 5.9 6.4± 6.9 7± 8.2
9.5± 2.2 10.8± 2.5 12.5± 2.8 14.1± 2.9 16± 3.6 19± 4.2 21.5± 4.4
10.2± 2.5 12.1± 2.8** 13.9± 2.5** 15.7± 3.6** 17.1± 3.9* 18.8± 4 22.8± 5.6
Handgrip Test (kg)
Maximal Strength
95.3± 19.2 100.4± 14.9 111.7± 16.6 113.2± 17.9 118.8± 19.5 129± 21.2 132± 24.4
106.5± 16.3** 113.6± 19.1** 122.4± 17.9** 125.1± 20.5** 131± 18.3** 141.4± 23.5** 148.9± 25.6**
Broad Jump Test (cm)
Explosive Strength
18.6± 6* 17.6± 5.6* 18± 5.9** 16.7± 6.7 17.8± 7** 17.3± 6.8** 19± 7.1**
16.3± 5.1 16.2± 5.2 15.2± 5.3 15.3± 6.5 12.8± 6.5 13.3± 6.1 12.5± 6.9
Sit and Reach Test (cm)
Flexibility
1.5± 0.7 2± 1 2.3± 1.3 2.3± 1.3 2.8± 1.4 3.1± 1.5 3.8± 1.7
2.1± 1.3** 2.5± 1.4* 3± 1.9* 3.5± 2** 3.8± 1.9** 4.5± 2.1** 5.1± 2.1**
(stage)
47.9± 1.5 47.1± 2.1 46± 2.8 44.2± 3 43.3± 3.4 42.3± 3.8 42.4± 4.3
49.3± 2.8** 48.2± 3.1* 47.4± 4.3* 46.8± 4.6** 45.9± 4.5** 45.9± 5.3** 45.7± 5.4**
VO2max (mL/kg/ minutes)†
Cardiorespiratory Endurance (20 m Endurance Shuttle Run Test)
*Mean differences by sex statistically significant (p ≤ .05). **Mean differences by sex statistically significant (p ≤ .001). † VO 2max , maximal oxygen consumption, calculated as: VO2max = 31.025 + 3.238S − 3.248A + 0.1536SA, where A, age; S, final speed (8 + 0.5× last stage completed). ‡ Lower values indicate better performance.
12.3± 6.1 14.9± 6.1* 16.7± 5.9* 18± 5.5* 19.7± 5** 20.5± 5.7* 21.9± 6.5*
Sit-Ups Test (Repeats)
5.6± 6.5* 6.6± 7* 8± 8.7* 8.4± 8.6* 9.6± 10.8** 10.4± 10** 11.8± 11.6*
Bent Arm Hang Test (s)
Boys (N= 868) 6 7 8 9 10 11 12 Girls (N= 857) 6 7 8 9 10 11 12
Age (Years)
Muscular Endurance
Muscular Strength
Table 1. Physical Fitness Scores (Mean ± SD) of EUROFIT Battery for Spanish Schoolchildren by Age and Sex
26.2± 3.1 25± 2.3 24.1± 2.8 23.9± 2.4 23.3± 2.8 22.5± 2.4 22.3± 2.3
25.2± 3** 24± 3.5* 23± 2.5* 22.5± 2.3** 21.8± 2.3** 21.4± 2.3** 21± 3.2**
Shuttle Run Test (10 × 5) (seconds)‡
Total Body Balance
23.1± 4.1 21± 3.6 18.3± 2.9 17.3± 2.9 15.6± 2.4 14.3± 1.9 13.4± 1.9
22.9± 3.9 20.5± 3.6 18.3± 3.1 17.1± 2.8 15.7± 2.5 14.7± 2.3 14± 2.3*
19.3± 6.3 13.8± 7.1 12.2± 7.6 11.6± 6.8 10.5± 7.8 8.7± 6.3 9.4± 7
20.3± 6.6 17.1± 7.6* 14.8± 7* 13.1± 7.4 11.4± 7.7 9.3± 6.7 9.5± 6.3
Plate Tapping Flamingo Test Test (seconds)‡ (no falls)‡
Speed
Figure 1. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Bent Arm Hang (s), (b) Sit-Up Test (repetitions), (c) Handgrip Test (kg), and (d) Broad Jump Test (cm)
Boys
Girls
(a)
40
40
Bent arm hang (s)
Upper-limbs muscular endurance
30
30
20
20
10
10
0
5
6
7
8
9
10
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13
0
5
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8
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9
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Trunk strength Sit-up test (repetitions)
(b) 40
40
30
30
20
20
10
10
0
5
6
7
8
9
10
11
12
13
0
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(c)
40
40
Handgrip test (Kg)
Upper-limb maximal strength
30
30
20
20
10
10
0
5
6
7
8
9
10
11
12
13
0
5
6
7
Lower-limb explosive strength
Broad jump test (cm)
(d) 200
200
150
150
100
100
50
50
0
0 5
6
7
8
9
10
11
12
13
5
6
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8
Age (years)
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Figure 2. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Sit and Reach Test (cm), (b) 20-m Shuttle Run (min), and (c) 20-m Shuttle Run (mL/kg/minutes)
Boys
Sit and reach test (cm)
(a)
Girls Flexibility
35
35
30
30
25
25
20
20
15
15
10
10
5
5 0
0 5
6
7
8
9
10
11
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13
6
7
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12
13
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9
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13
Cardiorespiratory endurance 10
8
8
6
6
4
4
2
2
20-m shuttle run (min)
(b) 10
0
0 5
6
7
8
9
10
11
12
5
13
VO2 max 20-m shuttle run (mL/Kg/min)
(c)
60
60
55
55
50
50
45
45
40
40
35
35
30
30 5
6
7
8
9
10
11
12
5
13
Age (years)
127.1 minutes/day is the average for boys and 100.9 minutes/day for girls.38 Similarly, the HBSC (Health Behaviors in School-aged Children) study in children aged 11 to 15 described that 54% of Latvian boys and 40% of Latvian girls performed 1 hour/day 630 •
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of MVPA, 5 days a week, compared to 46% of boys and 34% of girls in Spain.39 Our study can inform the physical fitness levels in schoolchildren (ages 6 to 12) from the center of Spain, and estimates the corresponding smoothed centiles •
© 2014, American School Health Association
Figure 3. Smoothed Centile Curves (From Top to Bottom: P90 , P75 , P50 , P25, and P10 ) for (a) Shuttle Run Test (10 × 5) (s), (b) Plate Tapping Test (s), and (c) Flamingo Test (Number of Falls). *Lower scores indicate better performance
Boys
Shuttle run test (10x5) (s)
(a)
Girls Speed of movement* 35
35
30
30
25
25
20
20
15
15
10
5
6
7
8
9
10
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10
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Speed and coordination of limb movement*
Plate tapping test (s)
(b) 30
30
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20
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10 5
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Total body balance* 35
30
30
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20
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15
10
10
5
5
Flamingo test
(c) 35
0
0 5
6
7
8
9
10
11
12
13
5
6
Age (years)
according to age and sex (Figures 1-3) that could be used as reference values to identify children with low fitness at school. According to other authors,10 falling below the lowest decile (P10 ) should be considered as a warning signal. In terms of population, having a fitness level below the 5th centile is usually considered an indicator of future cardiovascular risk.40,41 Other authors establish 5 risk categories based on the quintile in which one’s Journal of School Health
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fitness level lies.9 From a clinical point of view, it is more useful to establish fitness categories that are associated with future cardiovascular risk, such as those proposed by the Cooper Institute through data obtained from the FITNESSGRAM program. With those data, 2 categories, or ‘‘zones’’ were established, according to aerobic capacity: a Needs Improvement Zone (NIZ)—further divided into ‘‘some risk’’ and ‘‘high risk’’—and a Healthy Fitness Zone (HFZ).
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Figure 4. Physical Fitness Centile Curves (P10 , P50 , and P90 ) of 6 EUROFIT Tests From This Study (Castilla-La Mancha, Spain; CLM) and From 2 Countries (AUS, Australia and LAT, Latvia). *Lower scores indicate better performance Trunk strength-Sit-up test (a)
Upper-limb maximal strength-Handgrip test
30
(b)
Girls
Boys
Boys
P90 AUS P90 CLM
25
20
P50 AUS P50 CLM
20
Kg
15
10
P90 LAT
P10 CLM
15
P50 LAT
5
P50 CLM
5
P10 LAT P10 CLM
0
P10 AUS
10
P90 CLM
6
7
8
9
10 11 12
6
7
8
9
0
10 11 12
6
Speed of movement-Shuttle run test* (10x5) (c)
Girls
30
25
Repetitions
35
(d)
Boys
8
9
10 11 12
6
7
8
9
10 11 12
Lower-limb explosive strength-Broad jump test
35 30
7
Girls
200
Girls
Boys
180 160
25
140 120
s
cm
20 15
80
P90 LAT P90 CLM
10
40
P50 CLM P10 LAT
20
P10 CLM
(e) 9
0 6
7
8
9
10 11 12
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10 11 12
5
9
10 11 12
6
40
7
8
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10 11 12
Girls
Boys
P90 AUS P90 CLM P50 AUS P50 CLM P10 AUS P10 CLM
30 25
4
20 15
3
10
2
5
1
0 6
7
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10 11 12
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10 11 12
Age
•
8
35
P90 AUS P90 LAT P90 CLM P50 AUS P50 LAT P50 CLM P10 AUS P10 LAT P10 CLM
6
632
7
Flexibility-Sit and reach test (f)
Girls
Boys
7
0
6
Cardiorespiratory endurance-20-m shuttle run test
8
min
7
cm
0
P90 AUS P90 CLM P50 AUS P50 CLM P10 AUS P10 CLM
60
P50 LAT
5
100
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10 11 12
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Age
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10 11 12
Considering jointly the NIZ areas, 26% of girls and 13% of boys ages 10-12 from our study are at levels of aerobic capacity associated with future cardiovascular risk. We observe that the percentage of girls that show future cardiovascular risk is twice that of boys, whereas maintaining this relationship in the 2 risk subzones. According to these data, 1 in 4 girls and 1 in 10 boys have a high likelihood of cardiovascular disease in adulthood if their CRF does not improve. Our data are similar to those found in American children who, when the new FITNESSGRAM cutoff points were used, showed that 27.2% of girls and 19% of boys have cardiovascular risk associated with low CRF.17 Our data are also similar to those found in Portugal, where 28.3% of girls and 18.5% of boys showed cardiovascular risk associated with low CFR, according to the Cooper Institute criteria of 1999.42 Our data contrast with those of the EYHS (European Youth Heart Study), in which more than 40% of Swedish and Estonian schoolchildren aged 9 to 10 had levels of aerobic capacity associated with cardiovascular risk.43 In view of the low prevalence of overweight, and the high levels of physical activity of Swedish and Estonian children,44,45 the estimates of low aerobic capacity reported in the EYHS are surprising. We believe that, in addition to the fact that different cutoff points were used in the EYHS, these differences in the estimates of the prevalence of NIZ could be attributed to differences in the methodology used for estimating ´ equation using data VO2max . In our study, Leger’s from the 20-m shuttle run test was used for the indirect estimation of VO2max , whereas in the EYHS was directly assessed by means of a maximal cycle ergometer fitness test. To our knowledge, there are no prevalence data of cardiovascular risk associated with low CRF in Spanish children aged 10-12 using the new ´ et al30 working criteria of Cooper Institute.46 Casajus with children in Aragon, a region of northern Spain, reported that 9.1% of boys and 4.8% of girls do not reach the minimum levels recommended for healthy cardiovascular fitness. These percentages are clearly lower than those reported in our study. One possible explanation lies in the use of different cutoff points to categorize children at risk of future cardiovascular disease: 42 and 38 mL/kg/minutes for boys and girls respectively vs, in our study, 37.3 mL/kg/minutes for boys and girls aged 10-11, and 37.6 mL/kg/minutes for boys aged 12 and 37.0 mL/kg/minutes for girls aged 12. In the HELENA study, a European study including adolescents from 9 countries, 39% of boys and 43% of girls had high probability of future cardiovascular disease because of low CRF.10 These high figures during adolescence coincide with the gradual abandonment of physical/athletic activity that occurs among schoolchildren with the arrival of adolescence, which may explain the differences between children and adolescents. Journal of School Health
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Limitations One of the major limitations of this study is that it includes children from only a single region of Spain; therefore, inferences to all Spanish children should be made cautiously. However, the sample size, the inclusion of both rural and urban schools, and the similarity between fitness values found in our study and those found in other studies conducted in different geographical areas of Spain,21,30,47,48 all suggest that our data may be representative of the set of Spanish children aged 6-12. However, because our study is a cross-sectional one, it may be that a cohort effect has occurred, and as a consequence, our estimations of fitness levels could not be extrapolated to previous cohorts. Finally, a decrease in the prevalence of overweight in Spanish schoolchildren would likely improve CRF in terms of VO2max (mL/kg/minutes), and thus lower future cardiovascular risk. Conclusions Our study shows the physical health levels of Spanish schoolchildren aged 6-12 of Castilla-La Mancha, Spain, which could be useful in identifying children with low fitness and developing strategies to improve it. The physical fitness of Spanish children is worse than that of children from other countries. Within Spain, 1 in 4 girls and 1 in 10 boys has a level of CRF indicative of future cardiovascular risk. The high prevalence of cardiovascular risk associated with low aerobic capacity and low levels of strength compared with other countries in our study highlights the need to make deliberate, carefully planned efforts in the Spanish schools to improve the physical fitness of schoolchildren.
IMPLICATIONS FOR SCHOOL HEALTH With 1 in 5 schoolchildren exhibiting aerobic capacity levels associated with future cardiovascular risk, Spanish schoolchildren are less physically fit than their counterparts outside Spain. It has been suggested that these alarming figures are associated with low levels of physical activity in the population.37 Because of the relationships between fitness and cardiovascular risk,49 and between physical exercise and fitness50 that have been described, it is necessary to implement physical activity programs focused on the improvement of aerobic capacity and muscular strength. Such programs would obviously require collaboration among schools, health workers, politicians, and families. Schools are places where children spend a large amount of time, and thus, function as a setting in which to implement interventions to fight against sedentariness in infancy and, as a consequence, against cardiovascular disease in the coming years. Several strategies for promoting physical activity on schools
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have demonstrated some effectiveness in improving cardiometabolic health;51 thus, the challenge at this moment is to implement these interventions in an environment of economic crisis, even if they have a proven acceptable cost effectiveness ratio.52 In Spain, this challenge has a pivotal role as 2 circumstances converge: first, the time allocated to physical exercise is declining in the school schedules, and second, the prevalence of sedentary behavior during leisure time is increasing. To promote changes in students’ lifestyles, education and health authorities need to work with school directors to evaluate the implementation of physical activity programs of moderate to vigorous intensity, which could take place during a recess or before or after school hours. These programs should include recreational activities, sports, dancing, and outdoor activities. It would be desirable for these programs to include interventions that reach beyond the school to improve other aspects of a healthy lifestyle, such as eating habits or commuting behavior.53 We have gathered values for the health-related physical fitness of children aged 6-12 in Castilla-La Mancha, Spain. These values can be used both to assess students’ fitness levels and to detect the students whose fitness levels are below a healthy minimum.
7.
8.
9.
10.
11.
12. 13.
14. 15.
16.
Human Subjects Approval Statement The study was approved by the Ministry of Education and Science of the Regional Government of Castilla-La Mancha, and the Faculty of Education at the University of Castilla-La Mancha, Spain. All parents or guardians of the subjects participating in the study signed informed consent forms to participate in the study.
19.
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