Effects of weight loss on fitness in obese children

The relationship between weight and fitness change was established in 113 obese preadolescents participating in a six-month behavioral weight control program. Results showed significant improvements for both weight and fitness. Program success was strongly related to changes in exercise heart rate. Children who were most successful in the program decreased their maximal and recovery heart rates by 10.1 and 17.8 beats per minute, children with medium success had decreases of 4.9 and 11.8 beats per minute, and least successful children had decreases of 3.9 and 6.4 beats per minute. Analyses revealed that the combination of effective weight loss and an initially moderate degree of overweight (40% to 50%) combined to produce the greatest fitness changes. Children who entered treatment more than moderately overweight achieved comparable fitness improvements only if their weight loss was dramatic.