Severely overweight adolescents aged between 14 and 18 who want to lose weight and have enough will power to get up and exercise are best off combining strength training and cardio workouts. Canadian researchers at the University of Calgary believe that the combination leads to more fat loss than either strength training or cardio training alone.
In the Canadian study, which was recently published on the prestigious JAMA website, the researchers got fat teenagers to train four times a week for 22 weeks. They also put the adolescents on a diet that provided them with 250 kcal fewer than they burned.
In total the researchers used 304 subjects, making it a large study. This is probably one of the reasons that the researchers were able to publish their findings in JAMA.
The researchers divided their subjects into four groups. One, the control group, ate less but did no exercise. Another group did strength training, yet another did cardio, and the fourth group did both kinds of training. All active groups also ate a reduced-calorie diet.
The combination group lost most fat: 1.7 kg. The cardio and strength training groups lost only 1.2 and 1.3 kg fat respectively. The subjects in the control group actually put on weight during the experiment.
The active group members’ fat loss was mainly in the waist region, as the figure above shows.
“Aerobic training, resistance training, and their combination decreased percentage body fat in obese adolescents”, the Canadians conclude. “Combined aerobic and resistance exercise training tended to be superior to aerobic training alone in decreasing percentage body fat, waist circumference, and BMI.”
“Adolescents who want to maximize the effect of exercise on these variables should ideally perform both aerobic and resistance exercise, but significant benefit can be achieved through either type of exercise alone.”
Hmm… Those adolescents are going to have to be pretty motivated. The Canadians’ results are pretty pathetic: almost six months of exercising daily and only 2 kg fat loss to show for it? These teens must have trained like wimps and not taken the diet seriously at all.
Effects of Aerobic Training, Resistance Training, or Both on Percentage Body Fat and Cardiometabolic Risk Markers in Obese Adolescents: The Healthy Eating Aerobic and Resistance Training in Youth Randomized Clinical Trial.
Little evidence exists on which exercise modality is optimal for obese adolescents.
To determine the effects of aerobic training, resistance training, and combined training on percentage body fat in overweight and obese adolescents.
Design, Setting, and Participants:
Randomized, parallel-group clinical trial at community-based exercise facilities in Ottawa (Ontario) and Gatineau (Quebec), Canada, among previously inactive postpubertal adolescents aged 14 to 18 years (Tanner stage IV or V) with body mass index at or above the 95th percentile for age and sex or at or above the 85th percentile plus an additional diabetes mellitus or cardiovascular risk factor.
After a 4-week run-in period, 304 participants were randomized to the following 4 groups for 22 weeks: aerobic training (n?=?75), resistance training (n?=?78), combined aerobic and resistance training (n?=?75), or nonexercising control (n?=?76). All participants received dietary counseling, with a daily energy deficit of 250 kcal.
Main Outcomes and Measures:
The primary outcome was percentage body fat measured by magnetic resonance imaging at baseline and 6 months. We hypothesized that aerobic training and resistance training would each yield greater decreases than the control and that combined training would cause greater decreases than aerobic or resistance training alone.
Decreases in percentage body fat were -0.3 (95% CI, -0.9 to 0.3) in the control group, -1.1 (95% CI, -1.7 to -0.5) in the aerobic training group (P?=?.06 vs controls), and -1.6 (95% CI, -2.2 to -1.0) in the resistance training group (P?=?.002 vs controls). The -1.4 (95% CI, -2.0 to -0.8) decrease in the combined training group did not differ significantly from that in the aerobic or resistance training group. Waist circumference changes were -0.2 (95% CI, -1.7 to 1.2) cm in the control group, -3.0 (95% CI, -4.4 to -1.6) cm in the aerobic group (P?=?.006 vs controls), -2.2 (95% CI -3.7 to -0.8) cm in the resistance training group (P?=?.048 vs controls), and -4.1 (95% CI, -5.5 to -2.7) cm in the combined training group. In per-protocol analyses (?70% adherence), the combined training group had greater changes in percentage body fat (-2.4, 95% CI, -3.2 to -1.6) vs the aerobic group (-1.2; 95% CI, -2.0 to -0.5; P?=?.04 vs the combined group) but not the resistance group (-1.6; 95% CI, -2.5 to -0.8).
Conclusions and Relevance:
Aerobic, resistance, and combined training reduced total body fat and waist circumference in obese adolescents. In more adherent participants, combined training may cause greater decreases than aerobic or resistance training alone.
clinicaltrials.gov Identifier: NCT00195858.
[PubMed – as supplied by publisher]