Effects of exercise intensity on cardiovascular fitness, total body composition, and visceral adiposity of obese adolescents

• Published in: The American journal of clinical nutrition 2002-05, Vol.75 (5), p.818-826
• Main Authors: Gutin, Bernard, Barbeau, Paule, Owens, Scott, Lemmon, Christian R, Bauman, Mara, Allison, Jerry, Kang, Hyun-Sik, Litaker, Mark S
• Format: Article
• Language: English
• Subjects: adipose tissue; Adipose Tissue - pathology; adiposity; Adolescent; adolescents; Biological and medical sciences; Body Composition; Body fat; Cardiovascular Physiological Phenomena; Diet; dual-energy X-ray absorptiometry; energy expenditure; Exercise; Exercise - physiology; exercise test; Humans; image analysis; magnetic resonance imaging; Medical sciences; Metabolic diseases; Obesity; Obesity - pathology; Obesity - physiopathology; Physical Endurance - physiology; Physical Fitness; Teenagers; Viscera
• ISSN: 0002-9165; 1938-3207
• DOI: 10.1093/ajcn/75.5.818

Background: Little is known about how the intensity of exercise influences cardiovascular fitness and body composition, especially in obese adolescents. Objective: Our goal was to determine the effects of physical training intensity on the cardiovascular fitness, percentage of body fat (%BF), and visceral adipose tissue (VAT) of obese adolescents. Design: Obese 13-16-y-olds (n = 80) were assigned to 1) biweekly lifestyle education (LSE), 2) LSE + moderate-intensity physical training, or 3) LSE + high-intensity physical training. The intervention lasted 8 mo. Physical training was offered 5 d/wk, and the target energy expenditure for all subjects in physical training groups was 1047 kJ (250 kcal)/session. Cardiovascular fitness was measured with a multistage treadmill test, %BF with dual-energy X-ray absorptiometry, and VAT with magnetic resonance imaging. Results: The increase in cardiovascular fitness in the high-intensity physical training group, but not in the moderate-intensity group, was significantly greater than that in the LSE alone group (P = 0.009); no other comparisons of the 3 groups were significant. Compared with the LSE alone group, a group composed of subjects in both physical training groups combined who attended training sessions ≥2 d/wk showed favorable changes in cardiovascular fitness (P < 0.001), %BF (P = 0.001), and VAT (P = 0.029). We found no evidence that the high-intensity physical training was more effective than the moderate-intensity physical training in enhancing body composition. Conclusions: The cardiovascular fitness of obese adolescents was significantly improved by physical training, especially high-intensity physical training. The physical training also reduced both visceral and total-body adiposity, but there was no clear effect of the intensity of physical training.