Vahid Saleh - Ph.D Student of Sport Physiology, Department of Physical Education and Sport Sciences, Faculty of Education and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran.
Roghayyeh Afroundeh - Assistant professor of Physical Education and Sport Sciences, Faculty of Education and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran.
Marefat Siahkouhian - Professor of Physical Education and Sport Sciences, Faculty of Education and Psychology, University of Mohaghegh Ardabili, Ardabil, Iran.
Asadollah Asadi - Associate Professor of Biology, Faculty of Science, University of Mohaghegh Ardabili, Ardabil, Iran.

Background: Inconsistent results have been reported about the relationship between low RMR and obesity. The purpose of this study was to investigate the relationship between resting metabolic rate and body composition factors in obese and normal weight gymnastics children. Materials and Methods: ۲۰ obese and ۲۱ normal-weight boys, aged ۸-۱۲ years, participated in this study. In the first session, data regarding the participants’ anthropometrical (weight, height, waist to hip ratio (WHR)) and body composition (body fat percentage (BF%), body fat weight (BFW), and lean body weight (LBW)) measurements were recorded. In the next session, at first, subjects rested for ۱۵ min and then performed a modified Bulk exhausting test. The subjects were connected to the mouthpiece of gas analyzer throughout the rest and exhausting test and VO۲max, RER, and RMR were conducted in both groups. Results: Significant difference was observed for a mean of VO۲max, weight, BF%, BFW, LBW, and WHR between the two groups (P=۰/۰۰۱). The mean of RMR per kg body weight was significantly lower in the obese group than in the normal-weight group (P<۰/۰۵). There was no significant difference in the RER variable between the two groups (P>۰.۰۵). There was a significant linear relationship between RMR with weight, WHR, BFW, LBW, and VO۲max in the obese group (P≤۰/۰۵). Conclusion: Based on the results of the present study it can be concluded that the difference between the weight of obese and normal-weight beginner gymnast children is partly due to low RMR; and the lower RMR in obese children might be due to their low cardiorespiratory fitness.

Body composition, Maximal Oxygen Consumption, Obese children, Resting Metabolic Rate