ABSTRACT
BACKGROUND: The aim of our study was to evaluate the impact of the ActTeens Program on physical activity and health-related physical fitness among adolescents in Brazil. METHODS: The "ActTeens Program" was conducted using a cluster-randomized controlled trial during 24-week school term. The sample consisted of 317 adolescents (52.7% girls; 13.61 ± 0.70 years) from four secondary schools that were randomly assigned to intervention group (N = 169) or control group (N = 148). This school-based physical activity (PA) intervention involved two components: (i) structured physical activity sessions delivered within physical education (PE) and (ii) healthy lifestyle guidance (mHealth). The primary outcome was PA assessed using Physical Activity Questionnaire for Adolescents (PAQ-A); secondary outcomes included muscular (MF) and cardiorespiratory fitness (CRF) assessed using 90-push-up, handgrip dynamometer, standing long jump, and 20 m PACER shuttle run test. Assessments were conducted at baseline, 12- and 24-week. Intervention effects were assessed using linear mixed models (LMM). RESULTS: For the primary outcome (PA), no significant group-by-time effects were observed for physical education based-PA (0.3 score; 95%CI: -0.1; 0.6; and - 0.01 score; 95%CI: -0.03; 0.03, at 12-wk and 24-wk respectively) and total PA (-0.02 score; 95%CI: -0.2; 0.2; and - 0.01score; 95%CI: -0.2; 0.2, at 12 and 24 weeks respectively). After 24 weeks, we observed a significant group by time effects for lower body muscular fitness (12.9 cm; 95%CI, 3.2 to 22.2). CONCLUSION: The implementation of aerobic and muscle-strengthening exercises used in the ActTeens intervention did not lead to improvements in physical activity. The intervention resulted in improved lower body muscular fitness, however, we found no significant differences for upper body muscular and cardiorespiratory fitness.
Subject(s)
Exercise , Physical Education and Training , Physical Fitness , Humans , Female , Male , Adolescent , Exercise/physiology , Brazil , Physical Education and Training/methods , Cardiorespiratory Fitness/physiology , School Health Services , Health Promotion/methods , Program Evaluation , Healthy LifestyleABSTRACT
Background: /Objective: This study aimed to compare the effects of two combined training methods on health-related physical fitness components in adolescents. Methods: Seventy-six adolescents (16.1 ± 1.1 years, n = 44 female) were randomized into groups of moderate-intensity continuous training combined with resistance training (MICT + RT), high-intensity interval training combined with resistance training (HIIT + RT), or Control. The training sessions were performed twice weekly for 12 weeks. The health-related physical fitness components evaluated were: body composition, muscular and cardiorespiratory fitness. Results: The intervention groups had a significant reduction in body fat percentage and improvement in abdominal repetitions and VO2peak after 12 weeks of combined exercise program (p < 0.001). Intervention effects were found to significantly reduce body fat percentage for the MICT + RT and HIIT + RT groups compared to the control group (mean difference: -3.8; 95% CI: -6.2; -1 0.3; mean difference: -4.7; 95%CI: -7.1; -2.3, respectively). For muscle fitness, significant effects of the intervention were found in increasing the number of abdominal repetitions favoring the MICT + RT group compared to the control group (mean difference: 9.5; 95% CI: 4.4; 14.7) and HIIT + RT compared to the control group (mean difference: 14.1; 95% CI 9; 19.3). For cardiorespiratory fitness, significant effects of the intervention on improving VO2peak were found in the experimental groups (MICT + RT vs Control group: mean difference: 4.4; 95% CI: 2.2; 6.6; and HIIT + RT vs. Control group: mean difference: 5.5, 95% CI: 3.3; 7.7). Conclusion: The results suggest that 12 weeks of training using MCIT + RT or HIIT + RT showed a similar effect for health-related physical fitness components in adolescents.
ABSTRACT
BACKGROUND/OBJECTIVE: This study examined relationships between health-related physical fitness indicators and clustered cardiometabolic risk factors in adolescents between 2014 and 2017. METHODS: The sample consisted of 93 students (60% girls), with complete data sets in both 2014 and 2017. The physical fitness components evaluated were: flexibility (sit and reach), muscular fitness (curl-up and push-up), cardiorespiratory fitness (progressive aerobic cardiovascular endurance run), and body fat (BMI). The cardiometabolic risk factors were: waist circumference, blood pressure, high-density lipoprotein cholesterol (HDL-C), triglycerides and fasting blood glucose. Z-scores were calculated for each risk factor, with the sum of risk factor z-scores values used to represent clustered cardiometabolic risk. RESULTS: The results of cross-sectional analysis indicated that muscle fitness (curl-up: ß = -0.37, p < 0.001; push-up: ß = -0.38, p < 0.005) and cardiorespiratory fitness (ß = -0.56, p < 0.001) were inversely associated with clustered cardiometabolic risk, with BMI positively associated (ß = 0.58, p < 0.001). In the longitudinal analysis, cardiorespiratory fitness (ß = -0.33; p < 0.005) and body fat (ß = 0.46, p < 0.001) demonstrated a significant association with clustered cardiometabolic risk. However, no significant associations between the health-related physical fitness and clustered cardiometabolic risk were observed after adjustment for baseline values. CONCLUSION: Our cross-sectional findings highlight the importance of health-related physical fitness indicators to adolescents. In regarding the longitudinal analysis, further studies are needed in order to clarify the influence of physical fitness in the adolescence and cardiometabolic risk later in life.
