Adolescent physical performance and adult physical activity in Flemish males

Limited information is available about the associations between adolescent fitness levels and adult physical activity. In the present study, these associations are investigated using different indicators of physical activity. It is hypothesized that both health‐ and performance‐related fitness characteristics, observed during the adolescent period, contribute equally to the explained variance in adult physical activity levels. Subjects were 109 Flemish males followed over a period of 27 years from 13 to 40 years of age in the Leuven Longitudinal Study on Lifestyle Fitness and Health. Performance and health‐related fitness characteristics were observed during the growth period and at 40 years of age. The Work Index, Leisure Time Index, and Sport Index of the Baecke questionnaire were used as indicators of physical activity together with triaxial accelerometry. Multiple regression and discriminant analyses contrasting extreme quintiles of activity groupings were used to analyse the associations. Only the Baecke Sport Index showed consistent significant associations (R² = 0.03 to R² = 0.23) with adolescent fitness levels observed at 13, 15, and 18 years. When upper and lower quintiles were contrasted, fitness characteristics observed at the three age levels during adolescence were significantly different for each of the three indices of the Baecke questionnaire at 40 years of age. Lowest associations (R² = 0.09 to R² = 0.17) were found for the Work Index, followed by the Leisure Time Index (R² = 0.12 to R² = 0.28) and Sport Index (R² = 0.25 to R² = 0.43). Highest associations were evident for the 18‐ to 40‐year interval. Performance‐ and health‐related fitness characteristics explain equally well the variance in physical activity indicators. Am. J. Hum. Biol. 13:173–179, 2001. © 2001 Wiley‐Liss, Inc.     

Adolescent motor skill and performance: Is physical activity in adolescence related to adult physical fitness?

In the Amsterdam Growth and Health Longitudinal Study (AGAHLS), a cohort of about 400 boys and girls (mean age 13 years) were followed over a period of 20 years. Over that period repeated measurements were done of body dimensions (height, weight, skinfolds), physical fitness (eight motor performance field tests: plate tapping, bent arm hang, 10 × 5 m sprint, arm pull, sit and reach, standing high jump, 10 leg lifts, 12‐min endurance run, and one laboratory test to measure maximal aerobic power), and physical activity (by a cross‐check interview). Three research questions were studied: (1) Is there a positive relationship between adolescent fitness (age 13–17 years) and adult physical activity (age 33 years)? (2) Do physical fitness and physical activity track from adolescence into adulthood? (3) What is the longitudinal relationship between physical fitness and physical activity? Multiple linear regression analysis showed that of the 9 physical fitness tests, only the 12‐min endurance run and the maximal aerobic power during adolescence are significant (P < 0.05) predictors of adult physical activity. The effects are not influenced by biological age but by sex: only in females are the predictions significant (P < 0.05) Tracking over the period of 20 years estimated from stability coefficients showed values for physical fitness varying between 0.83 (plate tapping) to 0.38 (standing high jump and maximal aerobic power). Physical activity shows lower stability coefficients (0.35–0.29). A longitudinal linear regression technique was used to analyse the relationship between physical activity and physical fitness over the 20‐year period; in this analysis corrections were made for both time‐dependent (time, biological age, and cardiovascular factors) and time‐independent variables (sex). All physical fitness tests show positive and significant (P < 0.05) standardized regression coefficients with physical activity, but the explained variance is less than 1%. Only maximal aerobic power has a higher explained variance of 1.8%. It can be concluded that: (1) Physical fitness in adolescence is only weakly related to adult physical activity; (2) between age 13 and 33 years, physical activity has low stability and physical fitness was higher stability; and (3) the longitudinal relationships between physical fitness and physical activity are only meaningful with maximal aerobic power. Am. J. Hum. Biol. 13:180–189, 2001. © 2001 Wiley‐Liss, Inc.     

Somatotype and indicators of metabolic fitness in youth

The relationship between physique and metabolic fitness was examined in a sample of 413 boys and 343 girls 9–18 years of age from Phase I of the Québec Family Study. Physique was assessed using the Heath-Carter anthropometric somatotype. Indicators of metabolic fitness were plasma triglyceride levels (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), and blood glucose levels (GLY). The sample was divided into three age groups, 9–12, 13–15, and 16–18 years of age. A partial canonical correlation analysis was used to quantify the relationship between the standardized somatotype and metabolic fitness variables (z-transformed) with age as the covariate. In both boys and girls the first canonical correlation is significant (P ⩽ 0.001) and indicates a relationship between the physique and metabolic fitness variables. By age group, the 16–18 year old boys, and the 9–12, 13–15, 16–18 year old girls demonstrate significant canonical correlations (P ⩽ 0.03). Overall, 8% to 19% of the variance in metabolic fitness can be explained by the Heath-Carter anthropometric somatotype. The makeup of the canonical variates is similar for all age groups. Generally, the physique domain is characterized by a positive loading for ectomorphy and negative loadings for endomorphy and mesomorphy. The metabolic fitness domain has a positive loading for HDL-C and negative loadings for TG, LDL-C, and GLY. The results suggest that in youth 9–18 years, a physique characterized by high endomorphy and mesomorphy is associated with higher levels of TG, LDL-C, and GLY, and lower levels of HDL-C. Am. J. Hum. Biol. 10:341–350, 1998. © 1998 Wiley-Liss, Inc.     

Relationships of motor performance of adult men to anthropometry: A multivariate analysis

Relationships between 12 anthropometric characteristics and motor performance, as measured by various fitness tests, were considered in a sample of 165 Flemish adults observed at age 30 years. In addition to a bivariate correlation study, a canonical correlation analysis was carried out. More than 72% of the variance was shared by the first three canonical variables. The first canonical variable can be explained as a general size function. Static and functional strength are clearly related to this function. The second canonical variable can be interpreted as a size-fatness function. Nearly all motor tests are projected on the second composite, indicating that in adult men, subcutaneous fatness is negatively related to physical fitness. By means of a biplot of the first two canonical variables, interrelationships between body dimensions and motor performance are clarified. A combination of the first two functions seems to provide information about physique. © 1993 Wiley-Liss, Inc.     

Daily physical activity and physical fitness from adolescence to adulthood: A longitudinal study

The stability of physical fitness and physical activity in Flemish males from 18 to 40 years of age was investigated. In addition, effects of a consistently low-activity or high-activity level during the same age period on physical fitness were studied. The sample consisted of males who were followed longitudinally from age 13 to age 18 years, and were remeasured at the ages of 30, 35, and 40 years. Complete data about physical fitness and physical activity between 13 and 40 years were available for 130 subjects. Stability was measured using Pearson autocorrelations and simplex models. Multivariate analysis of variance (MANOVA) for repeated measurements was used to look for the effects of activity level on physical fitness. Simplex models showed higher stability coefficients than Pearson correlations, and stability of physical fitness was higher than stability of physical activity. Physical fitness showed the highest stability in flexibility (r = 0.91 between 18 and 30 years, r = 0.96 for both the 30–35 and 35–40 ages intervals), while physical activity showed the highest stability during work (r between 0.70 and 0.98 for the 5-year intervals). Results from MANOVA indicated that for some fitness characteristics the high-active subjects were more fit than their low-active peers. Stability of physical activity was higher than assumed and, therefore, it is a useful and independent indicator for further research. Although possible confounding factors are present (e.g., heredity), a higher level of physical activity during work and leisure time on a regular basis benefits physical fitness considerably. Am. J. Hum. Biol. 12:487–497, 2000. © 2000 Wiley-Liss, Inc.     

Sociogeographic variation in the physical fitness of a cross-sectional sample of Flemish girls 13 to 18 years of age

Three aspects of physical fitness—somatic characteristics, motor fitness, and sport participation—of girls from different sociogeographic origins of Belgium were contrasted. The sample consisted of a cross-sectional sample of 4,528 Flemish girls 13 to 18 years of age, who were classified by dwelling area as rural, semi-urban, and urban. Somatic characteristics included 16 anthropometric dimensions, skeletal maturity, and somatotype. Motor fitness was assessed by 10 tests. Sociocultural background information and the level of sport participation were investigated by questionnaire and interview. Data were analysed via one-way analyses of variance and growth curves were plotted to compare the sociogeographic differentiation patterns in physical fitness variables. The results show small motor and somatic differences between rural and urban youngsters, which is explained by the process of conurbation. However, urban girls were significantly more involved in sports than their rural counterparts. This is most probably due to greater sport involvement of parents from urban girls and/or the differences in available sport facilities.     

Motor performance during adolescence and age thirty as related to age at peak height velocity

Relationships between motor performance, as measured by various fitness tests, and age at peak height velocity have been studied in a sample of 173 Flemish boys, measured yearly between +/- 13 and +/- 18 years and again as adults at 30 years of age. In addition to correlation studies, comparisons were made between boys with an early, average and late age at peak height velocity. To summarize the successive measurements during adolescence, a longitudinal principal component analysis was carried out. The first component can be interpreted as an average percentile level component. During adolescence, three performance tasks, namely speed of limb movement, explosive strength and static strength, are negatively related to age at peak height velocity; thus early maturers performed significantly better than late maturers. However, between late adolescence and adulthood, a cross-over of the average distance curves between 18 and 30 years of age was noted for almost all motor tasks. The late maturers not only caught up the early maturers, but there were significant differences for explosive strength and functional strength in favour of late maturers. In order to predict performance in adulthood from measures during adolescence, the following hypothesis is suggested: the best results at adulthood are obtained by those men who were already good performers during adolescence and who were late maturers, while the worst results are obtained by poor performers during adolescence who were early maturers.     

The heritability of the skin conductance orienting response: a longitudinal twin study

The orienting response is a widely used experimental paradigm that reflects the association between electrodermal activity and psychological processes. The present study examined the genetic and environmental etiology of skin conductance orienting response (SCOR) magnitude in a sample of twins assessed at ages 9-10, 11-13 and 14-16 years. Structural equation modeling at each visit showed that genetic influences explained 56%, 83%, and 48% of the total variance in SCOR at visits 1, 2, and 3, respectively, with the remaining variance explained by non-shared environmental factors. SCOR was moderately stable across ages, with phenotypic correlations between time points ranging from .35 to .45. A common genetic factor explained 36%, 45% and 49% of the variance in SCOR magnitude across development. Additional age-specific genetic effects were found at ages 9-10 and 11-13 years, explaining 18% and 35% of the variance, respectively. The genetic correlations among the three time points were high, ranging from .55 to .73, indicating a substantial continuity in genetic influences from ages 9 to 16. These findings suggest that genetic factors are important influences in SCOR magnitude during late childhood and adolescence.     

Secular trends in anthropometric characteristics, physical fitness, physical activity, and biological maturation in Flemish adolescents between 1969 and 2005.

In this study, secular trends in anthropometric characteristics, physical fitness, physical activity, and biological maturity over the past 25-35 years in Flemish adolescents were investigated. Representative cross-sectional samples of 12-18-year-old secondary school children (11,899 assessments in boys in 1969-1974, 4,899 girls in 1979-1980, 1,429 boys and 1,772 girls in 2005) and parent-offspring pairs tested at approximately the same age during adolescence (55 father-son pairs, mean age fathers = 15.47 years, mean age sons = 15.38 years; 62 mother-daughter pairs, mean age mothers = 16.63 years, mean age daughters = 15.01 years) were used. The cross-sectional data were analyzed in 6 yearly age-categories using Wilcoxon rank sum tests. For the parent-offspring data paired t-tests, simple linear regressions to adjust for parent-offspring differences in chronological age and multiple linear regressions to adjust for parent-offspring differences in chronological and skeletal age were conducted. The cross-sectional study generally revealed an increase in weight, stature, BMI, skinfolds and trunk-extremity index, and a decrease in the performance on several physical fitness tests. In the parent-offspring study, only sons were maturationally advanced compared to fathers. Even after adjustment for parent-offspring differences in chronological age and in chronological and skeletal age, results for stature, trunk-extremity index and physical fitness were generally similar to the cross-sectional study. No secular trend was observed for sports participation. The fact that the positive secular trends in weight, BMI, and skinfolds of the cross-sectional study were not entirely confirmed in the parent-offspring study is probably due to higher similarity in genetic and familial background, higher socio-economic status, and more health-consciousness of the latter.     

Stability of Genetic and Environmental Influences on P300 Amplitude: A Longitudinal Study in Adolescent Twins

This study examined the stability of genetic and environmental influences on individual differences in P300 amplitude during adolescence. The P300 component is an event-related brain potential (ERP) that has attracted much attention as a biological marker for disturbed cognitive processing in psychopathology. Understanding the genetics of this biological marker may contribute to understanding the genetics of the associated psychopathologies. In a group of 213 adolescent twin pairs, the P300 component was measured twice, the first time at age 16 and the second time 18 months later. A large part of the variance of the P300 amplitude could be explained by familial factors, with estimates ranging from 30% to 81%. Whether the familial resemblance was due to genetic or shared environmental factors depended on sex. For males, genetic factors explained familial resemblance in P300 amplitude, but for females such resemblance was likely due to shared environmental factors. The phenotypic stability of the P300 amplitude from 16 to 18 years was high in both sexes, and stability could be attributed largely to the same familial factors. There was no evidence that new familial influences emerged at age 18.     

Genetic variance in age‐related changes in running performance and growth during adolescence: A longitudinal twin study

The purpose of this study was to assess an effect of genotype on the patterns of age‐related changes in running performance and physical growth during adolescence. The total sample was 14 pairs of male and 25 pairs of female monozygotic (MZ) twins and 19 pairs of male and 15 pairs of female dizygotic (DZ) twins. Performance on the 50‐m dash and endurance run (1,500 m for boys and 1,000 m for girls, respectively) and stature and body mass were measured at yearly intervals from 12 to 17 years of age. A principal component analysis was applied to the longitudinal data, and within‐pair resemblance in the scores on the first, the second, and the third principal components was compared between MZ and DZ twins. The analysis was conducted with both sexes pooled because of the limited number of twin pairs. The first two principal components explained at least 87% of the total variance, while the third principal component (PC3) explained a smaller portion of the total variance (more than 5%) in the dash and the endurance run. However, the total variance was explained almost entirely (more than 96%) by the first two components in height and mass. The first principal component (PC1), which explained 67–84% of the total variance, was a good indicator of average performance/body size of individuals during the period of observation. The second (PC2) and the third components (PC3) could be considered as indicators of the “shape” of developmental/growth curves, which were not related to inter‐individual differences in the average performance/body size. Intraclass correlations (r_i) of the scores on PC1 were consistently higher for MZ than for DZ twins, and estimated genetic variance was significant in endurance run, stature and body mass. The situation was the same for the scores on PC2 and/or PC3. However, such a between‐genotype difference in r_i and a significant genetic variance were not observed in the dash. It was concluded that MZ twins are more similar in the patterns of age‐related changes in the performance of endurance run and physical growth during adolescence than DZ twins, suggesting a genetic contribution, while there was no evidence of a genetic contribution in the dash. Am. J. Hum. Biol. 13:71–80, 2001. © 2001 Wiley‐Liss, Inc.     

Genetic and environmental influences on growth from late childhood to adulthood: a longitudinal study of two Finnish twin cohorts

Objectives: Human growth is a complex process that remains insufficiently understood. We aimed to analyze genetic and environmental influences on growth from late childhood to early adulthood. Methods: Two cohorts of monozygotic and dizygotic (same sex and opposite sex) Finnish twin pairs were studied longitudinally using self‐reported height at 11–12, 14, and 17 years and adult age (FinnTwin12) and at 16, 17, and 18years and adult age (FinnTwin16). Univariate and multivariate variance component models for twin data were used. Results: From childhood to adulthood, genetic differences explained 72–81% of the variation of height in boys and 65–86% in girls. Environmental factors common to co‐twins explained 5–23% of the variation of height, with the residual variation explained by environmental factors unique to each twin individual. Common environmental factors affecting height were highly correlated between the analyzed ages (0.72–0.99 and 0.91–1.00 for boys and girls, respectively). Genetic (0.58–0.99 and 0.70–0.99, respectively) and unique environmental factors (0.32–0.78 and 0.54–0.82, respectively) affecting height at different ages were more weakly, but still substantially, correlated. Conclusions: The genetic contribution to height is strong during adolescence. The high genetic correlations detected across the ages encourage further efforts to identify genes affecting growth. Common and unique environmental factors affecting height during adolescence are also important, and further studies are necessary to identify their nature and test whether they interact with genetic factors. Am. J. Hum. Biol., 2011. © 2011Wiley‐Liss, Inc.     

Stability of variables associated with the metabolic syndrome from adolescence to adulthood: the Aerobics Center Longitudinal Study.

The purpose of the study was to examine the stability of variables associated with the metabolic syndrome from adolescence to adulthood. The sample included 48 subjects from the Aerobics Center Longitudinal Study who had one clinical visit during adolescence (mean age = 15.8 years) and a follow-up visit during adulthood (mean age = 26.6 years). The following variables were considered: treadmill time to exhaustion (TM), body mass index (BMI), waist circumference (WC), percent body fat (%BF), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), TC:HDL-C, triglycerides (TG), glucose (GLU), and systolic (SBP), diastolic (DBP), and mean (MAP) blood pressure. A composite risk factor score using variables consistent with the WHO and ATP III definition of the metabolic syndrome (WC, HDL-C, TG, MAP, and GLU) was calculated. Tracking coefficients were computed as partial correlations, controlling for length of follow-up (mean = 11 years). Tracking coefficients (r values) were moderate for all variables (TM, 0.53; BMI, 0.64; WC; 0.79;%BF, 0.44; TC, 0.62; HDL-C, 0.60; TG, 0.54; TC:HDL-C, 0.78; SBP, 0.45; and MAP, 0.41), except GLU (0.26) and DBP (0.21). The composite risk factor score also tracked moderately well (0.56) from adolescence into adulthood. The results support previous findings that variables associated with the metabolic syndrome track moderately well from adolescence to adulthood. The findings support the prevention and treatment of obesity, atherosclerosis, type 2 diabetes, and the metabolic syndrome during childhood and adolescence.     

Approaches for assessing the role of household socioeconomic status on child anthropometric measures in urban South Africa

The objectives of this article were to compare the variance explained in anthropometric outcomes when using individual measures of socioeconomic status (SES) versus different approaches to create SES indices within the urban African context, and to examine the influence of SES measured during infancy on child anthropometric outcomes at 7/8 years. Data from the 1990 Birth‐to‐Twenty cohort study set in Johannesburg‐Soweto, South Africa, were used (n = 888). Linear regression models were used to investigate the association between SES (individual and index measures) during infancy and anthropometric measures at age 7/8 years, controlling for sex, age, and population group. Both individual and index measures of SES explained similar proportions of the variance for each anthropometric outcome. SES measured during infancy influenced weight more than height at age 7/8 years in Johannesburg‐Soweto. Positive associations were found between SES and the anthropometric measures––ownership of a car, telephone, and having an inside flush toilet were the most significant SES variables. The similarities observed in the variance explained relating to the anthropometric outcomes suggest that researchers who want to adjust for SES in analyses could use an SES index to make statistical models more parsimonious. However, using such indices loses information relating to the specific socioeconomic factors that are important for explaining child anthropometrics. If the purpose of the research is to make policy recommendations for the improvement of child growth, individual SES variables would provide more specific information to target interventions. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.     

Affective symptoms at index hospitalization in childhood and depressive symptoms in adulthood: a "catch-up" study

PURPOSE: To analyze whether affective symptoms during psychiatric treatment in childhood or adolescence could predict the later development of depressive symptoms. METHOD: We used a "catch-up" design. A cohort of former child and adolescent psychiatric patients was assessed in adulthood with standardized instruments according to the criteria of ICD-10 (SCAN) and dimensional values for depression (both self-reported and observer-rated). Initial affective symptoms had been extracted from clinical records according to a standardized system (AMDP). RESULTS: We assessed 164 former patients. Twelve percent of these fulfilled diagnostic criteria of an affective disorder (F3) according to ICD-10. In univariate analyses of variance the depression scores were significantly related to affective symptoms during childhood treatment, even if the presence of an affective disorder at catch-up was considered as an independent covariate variable. Nevertheless, the latter variable explained a large part of the variance of depression scores, while initial affective symptoms explained no more than 6%. CONCLUSION: Affective symptoms in childhood and adolescence may predict the later development of subthreshold depressive symptomatology.     

Relationships between blood pressure, anthropometric characteristics and blood lipids in high- and low-altitude populations from Central Asia

We studied the relationships between blood pressure, anthropometric characteristics and blood lipids in 72 low altitude (LA) Uighurs (600 m), 91 LA-Kirghizs (900 m), 117 medium altitude (MA) Kazakhs (2100 m) and 94 high altitude (HA) Kirghizs (3200 m). All subjects were male and had a similar age (p = ns, ANOVA; range for all 374 subjects: 18-66 yr). Body weight (Wt), body mass index (BM1) and the sum of four skinfolds (4SF) were significantly lower in HA-Kirghizs than the remaining groups (p < 0.0005, p < 0.0005 and p < 0.05 respectively, ANOVA). However, no difference was found in body fat distribution as detected by waist:hip circumference (WHR) and triceps:subscapular skinfold ratios (TSR; p = ns, ANOVA). Stage 1 hypertension was detected in 18% of LA-Uighurs, 2% of LA-Kirghizs, 4% of MA-Kazakhs and 1% of HA-Kirghizs; stage 2 hypertension was detected in 2% of LA-Uighurs and none of the remaining groups; no subject had stage 3 hypertension (The Joint National Committee on Prevention. Detection, Evaluation and Treatment of High Blood Pressure 1997). Blood cholesterol (CH) and triglycerides (TG) did not differ between groups (p = ns, ANOVA). The relationships between systolic (SBP) or diastolic (DBP) blood pressure and age, Wt, BMI, 4SF, WHR, TSR, CH and TG were independent from altitude (p = ns, ANCOVA). In the pooled sample (n = 374), age explained 1 and 3% of SBP (p < 0.05) and DBP (p < 0.005) variance respectively, Wt was the best predictor of SBP and DBP explaining 11 and 10% of their variance respectively (p < 0.0001) and CH explained 5% of DBP variance (p < 0.0001). In conclusion, hypertension is more frequent in LA- than MA- and HA-subjects from Central Asia. However, anthropometric characteristics and blood lipids do similarly contribute to explain blood pressure in these subjects.     

Relationships between anthropometry,cardiorespiratory fitness indices and physical activity levels in different age and sex groups in rural Senegal (West Africa)

Background: A high level of activity is commonplace in traditional subsistence societies. Physiological characteristics of individuals, including body composition and physical fitness, could be limiting factors when performing daily tasks.

Objectives: The study investigated the relationships between cardiorespiratory fitness, nutritional status and physical activity patterns, so as to test the hypothesis that these relationships are less straightforward in children than in adults.

Study design: Four different groups of individuals from rural Senegal were investigated: 99 10–13-year-old children of both sexes (11.1?±?1.5 years old) from two settings in Senegal (Lambaye and Podor), 43 adolescent girls (15.5?±?0.5 years), and 30 adult women (17–40 years).

Methods: Subjects undertook a step test, and anthropometric measurements were collected. Continuous heart rate (HR) monitoring was performed for 8–12?h. The flex-HR method was used to estimate levels of activity (per?cent of time spent under or over the flex-HR).

Results: Ten to 13-year-old children and adolescent girls presented slight degrees of malnutrition. Adult women were apparently not nutritionally deprived. Differences in cardiorespiratory fitness were found among 10–13-year-old children, while adult women performed better than adolescent girls. Children from Lambaye had a higher level of activity than children from Podor. Similarly, adult women were more active than adolescent girls. No relationships were found between cardiorespiratory or anthropometric measurements and per?cent of time spent above the flex-HR (>flex-HR) in 10–13-year-old children. In contrast, in adult women and adolescent girls, body composition and cardiorespiratory indices were significant predictors of activity levels.

Conclusion: Our data support the hypothesis that activity levels are less dependent upon physiological characteristics in children than in adults in traditional subsistence societies.     

Relationships between anthropometry, cardiorespiratory fitness indices and physical activity levels in different age and sex groups in rural Senegal (West Africa)

BACKGROUND: A high level of activity is commonplace in traditional subsistence societies. Physiological characteristics of individuals, including body composition and physical fitness, could be limiting factors when performing daily tasks. OBJECTIVES: The study investigated the relationships between cardiorespiratory fitness, nutritional status and physical activity patterns, so as to test the hypothesis that these relationships are less straightforward in children than in adults. STUDY DESIGN: Four different groups of individuals from rural Senegal were investigated: 99 10-13-year-old children of both sexes (11.1 +/- 1.5 years old) from two settings in Senegal (Lambaye and Podor), 43 adolescent girls (15.5 +/- 0.5 years), and 30 adult women (17-40 years). METHODS: Subjects undertook a step test, and anthropometric measurements were collected. Continuous heart rate (HR) monitoring was performed for 8-12 h. The flex-HR method was used to estimate levels of activity (per cent of time spent under or over the flex-HR). RESULTS: Ten to 13-year-old children and adolescent girls presented slight degrees of malnutrition. Adult women were apparently not nutritionally deprived. Differences in cardiorespiratory fitness were found among 10-13-year-old children, while adult women performed better than adolescent girls. Children from Lambaye had a higher level of activity than children from Podor. Similarly, adult women were more active than adolescent girls. No relationships were found between cardiorespiratory or anthropometric measurements and per cent of time spent above the flex-HR (> flex-HR) in 10-13-year-old children. In contrast, in adult women and adolescent girls, body composition and cardiorespiratory indices were significant predictors of activity levels. CONCLUSION: Our data support the hypothesis that activity levels are less dependent upon physiological characteristics in children than in adults in traditional subsistence societies.     

Activity pattern,smoking habits,and somatometric variables of the Czechoslovakian population

Summary A total of 3762 subjects of both sexes, natives of Czechoslovakia, ranging in age from 12–55 years, were examined. Both anamnestic data and selected anthropometric variables were evaluated. The proportion of non-smokers for adult males was 47–56%, and for adult females was 54–74% of the population. The proportion of subjects not engaged in any type of physical activity decreases in boys between 12 and 18 years from 28 to 16%, in girls between 12 and 15 years from 25 to 22%; from then on the trend reverses and the percentage rises up to 42% in men and 65% in women. The number of subjects participating in competitive sporting activity reaches its peak at 18 years, when 46% of boys and 43% of girls compete, but than decreases quickly. 12 year old girls are taller and heavier than boys but at 15 years the relationship is reversed. The LBM at the age of 12 is equal in boys and girls, but from then till 18 years the increase is larger in boys. The LBM weight in adults remains steady, women attaining 77% of the value found in men. The skinfold increases with age similarly in both sexes, except for an interval between 12 and 18 years, when girls show a steeper increase. Adult women attain 121–160% of the values characteristic for men. The grip strength of the right hand equals about 50 kp in adult men and 30 kp in adult women. Within the age range followed, it remains unaffected by age.More than 50 specialists assisted in gathering the pertinent data     

Growth and motor performance of black and white children 6–10 years of age: A multivariate analysis

The relationships between anthropometry and physical performance were considered in 439 Black and 386 White children, 6 through 10 years of age. Anthropometric dimensions included weight, statute, sitting height, six skeletal breadths, three limb circumferences, and three skinfolds. Performance variables included four static strength and three motor tasks. Principal components analysis was used to reduce the anthropometric dimensions to four components for each age group (sexes combined) within race. Only two components had eigenvalues greater than 1 in all age and both racial groups. The first two components accounted for 81 to 87% of the variance in anthropometry in Black children and for 79 to 85% of the variance in White children. Path coefficients from sex directly to performance and the products of path coefficients from sex to the first or second principal component to performance were computed for each strength and motor task in each age and race group. With few exceptions, path coefficients from sex directly to performance were negative and suggested an effecct of sex on performance which is independent of anthropometric characteristics.