Abstract
Background: The Heart rate variability (HRV) as a measurement of autonomic function assumes great clinical importance. Children are vulnerable during the adolescence since in this period dietary and lifestyle patterns are initiated that have implications for coronary heart disease (CHD) and other morbidity risk in later adult life.

Aims & Objective: This study was devised to correlate HRV with WHR in male and female adolescent school children.

Materials and Methods: 195 school children of both sexes (boys 93 and girls 102) in the adolescent age participated in this study. Their WHR was measured and HRV was recorded during rest, immediately before exercise, 5 minutes and 30 minutes after exercise with deep breathing. On the basis of waist-hip ratio, these students were divided into lesser group, those having WHR less than the average of the respective groups and more group of those having WHR more than the average.

Results: The result showed that the HRV of girls were more than boys but it was lesser than boys immediately after exercise. In girls with lesser WHR recorded much less than others.

Conclusion: During adolescent age, girls have better parasympathetic control and comparatively during adolescent period, the lean people have better sympathetic activity. This findings is in oppose to adulthood autonomic control where male have better parasympathetic activity and in obese people sympathetic activity is more. The reason for paradoxical autonomic control in adolescent age lies in the onset of secretion of sex hormones during the adolescent period.

Key words: Adolescent, Heart Rate Variability , Waist-Hip-Ratio, sympathetic system, parasympathetic system.