Document Type : Research Paper I Open Access I Released under (CC BY-NC) license


1 Professor, University of Guilan

2 Nutritionist PhD


Aim: The purpose of this study was to investigate the effects of aerobic exercise on leptin and testosterone in obese boys’ serum at different pubertal stages.
Method: The cross-sectional study had a pre-test- post-test design. The subjects included 36 obese boys aged 12 to 17 years, who according to the Tanner index, were in the stage of puberty of TS2 to TS5. The subjects were divided in to two groups, TS2, 3 (n=19, age: 13.4±0.94 years, Weight: 76.61±16.7 kg, BMI: 29.41±5.22 kg/m2) and TS4, 5 (n=17, age: 14.9±1.48 years, Weight: 93.57±16.48 kg, BMI: 30.92±3.88 kg/m2), each divided into aerobic exercise and control groups. After anthropometric measurements, fasting serum’s leptin and testosterone levels were measured. The aerobic exercise group completed 12 weeks of running, three times a week 30 minutes on average with an intensity of 60 to 85 percent of maximum heart rate. A pedometer was used to measure the level of physical activity and N4 software was used for measurement of energy intake. The statistical t-test, one-way and two-way ANOVA was used to analyze the data.
Results: Lean body mass increased and body fat percent decreased significantly in aerobic exercise group at both stages of puberty (P≤0.05). In aerobic exercise group decrease in BMI and body fat, was only significant in TS4, 5 (P≤0.05). serum leptin levels decreased at different stages of puberty and was at only significant in aerobic exercise group (P≤0.05); but its changes in aerobic exercise and control groups at each stage of puberty wasn’t significant. Analysis of variance showed that puberty affects leptin changes (P≤0.05) but there was no significant difference between the effect of aerobic exercise on leptin decrease and changes in testosterone  in both groups (TS4, 5 and TS2, 3 )
Conclusion: The results indicated that aerobic exercise in obese adolescent boys can lead to favorable changes in body composition, along with decreased serum’s leptin.  However, part of these changes result from the normal maturation process that can lead to different responses to aerobic training, though due to the low number of subjects showing it about serum’s leptin, was not possible.