Search Results

The purpose of this meta-analysis of randomized trials was to determine the effectiveness of aerobic plus resistance exercise interventions on body composition related to variables in overweight and obese youth. A computerized search was made of 7 databases. The analysis was restricted to randomized controlled trials that examined the effect of aerobic and resistance exercise on body composition (body weight, body mass index, fat mass, fat-free mass, and waist circumference) in obese youth. Two independent reviewers screened studies and extracted data. Weighted mean differences (WMD) and 95% confidence intervals were calculated. Nine studies were selected for meta-analysis as they fulfilled the inclusion criteria (n = 365). Aerobic plus resistance exercise interventions (8–24 weeks duration) produced a decrease in body weight (WMD=-3.31 kg), body mass index (WMD=-1.05 kg/m²), and fat mass (WMD=-1.93% and 5.05 kg), but changes in fatfree mass and waist circumference were not observed. These changes were accentuated through programs of at least 60 min of exercise per session, generating greater reductions in body weight (WMD=-4.11 kg), fat mass (WMD=-4.07%), and increase in fat-free mass (WMD = 2.45 kg). This meta-analysis provides insight into the effectiveness of short-term aerobic plus resistance exercise interventions for decreasing body weight, body mass index, and fat mass in pediatric obesity.

The aim of this study was to examine the energy expenditure (EE) measured using indirect calorimetry (IC) during playground games and to assess the validity of heart rate (HR) and accelerometry counts as indirect indicators of EE in children´s physical activity games. 32 primary school children (9.9 ± 0.6 years old, 19.8 ± 4.9 kg · m^-2 BMI and 37.6 ± 7.2 ml · kg^-1 · min^-1 VO_2max). Indirect calorimetry (IC), accelerometry and HR data were simultaneously collected for each child during a 90 min session of 30 playground games. Thirty-eight sessions were recorded in 32 different children. Each game was recorded at least in three occasions in other three children. The intersubject coefficient of variation within a game was 27% for IC, 37% for accelerometry and 13% for HR. The overall mean EE in the games was 4.2 ± 1.4 kcals · min^-1 per game, totaling to 375 ± 122 kcals/per 90 min/session. The correlation coefficient between indirect calorimetry and accelerometer counts was 0.48 (p = .026) for endurance games and 0.21 (p = .574) for strength games. The correlation coefficient between indirect calorimetry and HR was 0.71 (p = .032) for endurance games and 0.48 (p = .026) for strength games. Our data indicate that both accelerometer and HR monitors are useful devices for estimating EE during endurance games, but only HR monitors estimates are accurate for endurance games.

Purpose: The present study aims to investigate the association between dual-energy X-ray absorptiometry (DXA) and quantitative ultrasound (QUS) parameters and the intermethods agreement in active males. Methods: In this cross-sectional study, bone health (by DXA and calcaneal QUS), physical activity (by accelerometers), and anthropometrics measurements were assessed in 117 active adolescents (12–14 y old). Bivariate correlation coefficients were calculated to assess the relationships between DXA standard regions of interest and QUS parameters. Intraclass correlation coefficients and Bland–Altman plots were used to assess the level of agreement between bone mineral content regions derived from DXA and stiffness index. The measurements were z score transformed for comparison. Results: Most QUS parameters were positive and significantly correlated with DXA outcomes (stiffness index: r = .43–.52; broadband ultrasound attenuation: r = .50–.58; speed of sound: r = .25–.27) with the hip showing the highest correlations. Moreover, the present study found fair to good intraclass correlation coefficients of agreement (.60–.68) between DXA and QUS to assess bone health. The Bland–Altman analysis showed a limited percentage of outliers (3.2%–8.6%). Conclusion: QUS device could represent an acceptable alternative method to assess bone health in active adolescent males.

This study determined the relationship between self-reported and objective measurements of physical activity with adiposity markers in a random sample of community-dwelling older adults. The sample included 439 individuals over 65 years (age 71.1 ± 7.8; 54.2% women). Regular physical activity information was collected using self-reported (questionnaire, 7-day-PAR) and objective measurements (accelerometer ActiGraph GT3X) over 7 days. Anthropometric parameters included body mass index, body fat percentage, and waist circumference. The number of patients considered active was 28% according to the results of 7-day PAR, and 69% according to objective measures of accelerometry. With every daily increase of 10 min of sedentary activity, the BMI, body fat percentage, and waist circumference values increased by 0.04 units, 0.14%, and 0.14 cm, respectively. According to the accelerometry data, being active was a protective factor for presenting obesity criteria (OR = 0.34, CI 95% 0.19–0.59). Objective but non self-reported physical activity was associated with adiposity markers in older adults.

Purpose: To examine the intermethods agreement of dual-energy X-ray absorptiometry (DXA) and foot-to-foot bioelectrical impedance analysis (BIA) to assess the percentage of body fat (%BF) in young male athletes using air-displacement plethysmography (ADP) as the reference method. Methods: Standard measurement protocols were carried out in 104 athletes (40 swimmers, 37 footballers, and 27 cyclists, aged 12–14 y). Results: Age-adjusted %BF ADP and %BF BIA were significantly higher in swimmers than footballers. ADP correlates better with DXA than with BIA (r = .84 vs r = .60, P < .001). %BF was lower when measured by DXA and BIA than ADP (P < .001), and the bias was higher when comparing ADP versus BIA than ADP versus DXA. The intraclass correlation coefficients between DXA and ADP showed a good to excellent agreement (r = .67–.79), though it was poor when BIA was compared with ADP (r = .26–.49). The ranges of agreement were wider when comparing BIA with ADP than DXA with ADP. Conclusion: DXA and BIA seem to underestimate %BF in young male athletes compared with ADP. Furthermore, the bias significantly increases with %BF in the BIA measurements. At the individual level, BIA and DXA do not seem to predict %BF precisely compared with ADP in young athletic populations.