As obesity continues to maintain a stranglehold on the teenage population, experts search for solutions to the potentially fatal disease. When it comes to exercise, a combination of cardiovascular and strength training is best, according to researchers from São Paulo.
Their study, published in the International Journal of Sports Medicine (2014; 35, 164–71), included 72 obese adolescents (50 girls and 22 boys) aged 15–19. Subjects participated for 6 months in one of three interventions: leisure-time physical activity, cardiovascular training, or cardiovascular plus strength training. The cardiovascular-only group completed three 60-minute treadmill-based running sessions per week under professional supervision. The combination group also met three times per week. Half of each session was spent running on a treadmill. The second half consisted of the following strength exercises: bench press, leg press, sit-up, lat pull-down, hamstring curl, low back, military press, calf raise, arm curl and triceps push-down. The order of the modalities alternated: One session began with the cardiovascular workout, the next started with resistance training, and so on.
“The first 2 weeks of the resistance training had as [their] main purpose the learning of the movements (3 sets of 15–20RM for each exercise),” the authors explained. “Training loads were successively adjusted, with volume and intensity being inversely modified and the number of repetitions being decreased to between 6 and 20 repetitions for 3 sets. The rest interval between series and exercises were: 15–20RM = 45 s; 10–12RM = 1 min and 6–8RM = 1.5 min. The training loads were adjusted in each training session and evaluated according to the increase in participants’ strength. Thus, the training was conducted with maximal repetitions (RM).”
Those in the leisure-time physical activity group also met three times per week, engaging by turn in recreational team sports, gymnastics and walking.
All participants maintained a specific calorie intake recommended by the researchers.
By study completion, the cardiovascular-only group had lost an average of nearly 13 pounds; fat mass had decreased by less than 1%. The combination exercise group lost an average of more than 18.5 pounds and reduced fat mass by nearly 9%. Leptin scores improved in both groups. The leisure-time physical activity group’s data remained mostly unchanged.
“In conclusion, aerobic plus resistance training, as part of an interdisciplinary therapy, is effective in improving body composition, including a decrease in body fat and increase in lean body mass, and leptin concentration in obese adolescents,” the author said. “However, despite the same improvement in lean body mass not being observed with aerobic training, this group was also able to reduce the leptin concentration after 6 months of intervention.”