This study examined the effect of aerobic training on leg strength, power, and muscle mass in previously sedentary, healthy older men (70–80 yr). Training consisted of 30–45 min of cycle ergometry at 50–70% maximal oxygen consumption (VO2max), 3 times weekly for 16 wk, then 4 wk detraining, or assignment to a nontraining control group (n = 12 both groups). Training increased leg strength, leg power, upper leg muscle mass, and VO2max above pretraining values (21%, 12%, 4%, and 15%, respectively; p < .05). However, all gains were lost after detraining, except for some gain in VO2max. This suggests that cycle ergometry is sufficient stimulus to improve neuromuscular function in older men, but gains are quickly lost with detraining. For the older population cycle ergometry provides the means to not only increase aerobic fitness but also increase leg strength and power and upper leg muscle mass. However, during periods of inactivity neuromuscular gains are quickly lost.
Dale I. Lovell, Ross Cuneo and Greg C. Gass
Chiaki Tanaka, Yuki Hikihara, Kazunori Ohkawara and Shigeho Tanaka
This study examined the potential relationship between participation in physical activity (PA) assessed by triaxial accelerometry and physical fitness testing, including health-related and skill-related parameters of fitness, in 136 Japanese preschoolers (65 girls and 71 boys, 5.5 ± 0.6 years). In partial correlation analyses, grip strength and 20m shuttle run test were positively correlated with time spent in physical activity ratio (PAR) ≥ 4. Better scores on standing long jump distance and jump over and crawl under tests were associated with lower sedentary time and greater moderate-to-vigorous PA time and PAR ≥ 4 time, and increased physical activity level. Moreover, 25m run speed was positively correlated with time spent in PAR ≥ 4 and locomotive activity. These findings suggest that development of both health-related (muscle strength and aerobic fitness) and skill-related fitness (power, agility and speed) may make engagement in PA easier for preschool children, although further research on the cause-effect relationship is needed.
Lennart Raudsepp and Toivo Jürimäe
The purpose of this study was to examine the relationships between physical activity and physical fitness and adiposity in a sample of 77 girls, aged 10–11 years. Physical activity was assessed by 7-day physical activity recall by which children reported how much time they spent on low and moderate-to-vigorous physical activities. Physical fitness was measured by EUROFIT test battery. Adiposity was estimated by sum of five skinfolds. The main finding of the study was that moderate-to-vigorous physical activity and adiposity were significant predictors (with 16–34% accounted variance) of physical fitness tests where the body mass affects performance. Indicators of physical activity and adiposity were not significantly related with fitness items requiring muscular strength, balance, flexibility, and speed of limb movement. Furthermore, moderate-to-vigorous physical activity and aerobic fitness predicted 22% of variance in adiposity in girls.
Kenneth H. Pitetti and Bo Fernhall
The purpose of this study was to evaluate the relationship between aerobic capacity (VO2peak) and leg strength of male (n = 17) and female (n = 12) youths (age = 14.2 ± 2.1 years) with mild to moderate mental retardation. Aerobic capacity was determined by a treadmill test (GXT) and isokinetic knee flexion and extension strength (peak torque, peak force, average force) was determined by isokinetic dynamometry. Results indicate that significant positive relationships (p < .05) exist between VO2peak (ml · min−1 · kg−1) and isokinetic leg strength expressed relative to body weight. The results indicate that leg strength is a contributor to aerobic fitness in youths with mental retardation. Additionally, when considering the low levels of both strength and VO2peak, leg strength may be a limiting factor of VO2peak in these youths, or the relationship may be explained by the concept of metabolic nonspecialization.
Gregory J. Welk, Jodee A. Schaben and Mack Shelley
Homeschooling is increasingly popular, but little is known about how homeschooling affects physical activity patterns or fitness levels. This study compares patterns of physical fitness, physical activity, and psychosocial correlates of physical activity in homeschooled youth and youth attending public school. Fitness levels were obtained using the PACER aerobic fitness test, physical activity levels were assessed with 3 days of accelerometry, and psychosocial correlates were assessed with the Children’s Physical Activity Correlates scale. There were no significant main effects for fitness comparisons, but significant age and gender interactions indicate that variability exists within these samples for fitness. No school type effects were evident for the physical activity measures or the psychosocial correlate measures, but trends in the data suggest the possibility of age-related interactions for the psychosocial measures. Additional research on possible differences between homeschooled youth and youth attending public school is needed to better understand these trends.
Roy J. Shephard and François Trudeau
It is now well-established that well-designed programs can induce short-term gains in aerobic fitness, muscular strength, and physical performance, although during the primary school years, gains may be somewhat less than in adults. Long-term effects have as yet had little investigation. Most studies have looked simply at the tracking of activity patterns and associated lifestyle variables, usually from mid or late adolescence into early adult life. Although statistically significant, such tracking has been relatively weak. Further, in the absence of an experimental intervention, such studies provide little information on the long-term health value of physical education. The potential for obtaining definitive information is suggested by a long-term (20+ year) follow-up of participants in the Trois Rivières study. This program was well-perceived by participants, and the data obtained on adults suggest it may have had some favorable long-term impact on activity patterns, physiological parameters, and smoking behavior.
Akira Matsuzaka, Yuko Takahashi, Masayuki Yamazoe, Naomi Kumakura, Akiko Ikeda, Boguslaw Wilk and Oded Bar-Or
The purpose of this study was to examine the validity of a 20-m shuttle-run test as an aerobic fitness test for Japanese children, adolescents, and young adults. Participants were 62 boys and 70 girls aged 8–17 years and 56 men and 99 women aged 18–23 years. Stepwise regression analysis was used to elucidate the relationship between shuttle-run performance, age, gender, and anthropometric parameters (as independent variables) and peak oxygen uptake (VO2peak), determined directly on a treadmill, as a dependent variable. We observed high multiple correlations for adults (R 2 = .88) and for children and adolescents (R 2 = .80). Therefore, it is suggested that our multiple regression equations are more appropriate for predicting VO2peak in Japanese children, adolescents, and adults.
Kathleen F. Janz, Jeffrey D. Dawson and Larry T. Mahoney
To evaluate the effect of changes in aerobic fitness and physical activity on changes in lipoproteins, we measured body composition, peak V̇O2, vigorous and sedentary activity, maturation, and lipoproteins in 125 children (mean baseline age, 10.5 years) for 5 years. Change in variables was analyzed using the slopes of the regression line obtained by plotting the data for each child. No predictor variables were significant for girls. In boys, predictors of favorable changes in lipoproteins included decreases in fatness, increases in fitness, early maturation, and increases in fat-free body mass (FFM). Multivariable analysis, adjusted for baseline age, indicated that change in FFM explained 21% of the variability in change in LDL-C. Results suggest that during puberty, changes in activity and fitness do not predict changes in lipoproteins.
James N. Roemmich and John P. Frappier
This study compared successful (n=19) and less successful (n=19) varsity wrestlers matched for age, weight, height, and wrestling experience on physiological variables important for wrestling success using field tests available to a high school wrestling coach. Significant (P<0.05) differences in favor of the successful wrestlers were found for mean left and right grip strength, flexibility of the low back and hamstrings, completed sit-ups, pull-ups, and push-ups. Successful wrestlers also covered a greater distance during a 12min run test and had significantly greater relative anaerobic power (Margaria step test). The groups did not differ significantly in the sum-of-six skinfolds. In conclusion, successful wrestlers had significantly more muscular strength, muscular endurance, flexibility of the low back and hamstrings, aerobic fitness, and relative anaerobic power than less successful wrestlers. It is suggested less successful wrestlers engage in regular training sessions that include stretching, cardiovascular, and strength/power components.
Magnus Dencker, Bianca Hermansen, Anna Bugge, Karsten Froberg and Lars B. Andersen
This study investigated the predictors of aerobic fitness (VO2PEAK) in young children on a population-base. Participants were 436 children (229 boys and 207 girls) aged 6.7 ± 0.4 yrs. VO2PEAK was measured during a maximal treadmill exercise test. Physical activity was assessed by accelerometers. Total body fat and total fat free mass were estimated from skinfold measurements. Regression analyses indicated that significant predictors for VO2PEAK per kilogram body mass were total body fat, maximal heart rate, sex, and age. Physical activity explained an additional 4–7%. Further analyses showed the main contributing factors for absolute values of VO2PEAK were fat free mass, maximal heart rate, sex, and age. Physical activity explained an additional 3–6%.