Researches in the last decade have shown that heart rate in recovery period after exercise test is highly associated with mortality after cardiac events so that the amount of rest and exercise heart rate can indicate the severity of the risk of diabetes. But what is the connection between resting heart rate and activity in diabetics, athletes and healthy people has been neglected, so the aim of this study was to compare the resting heart rate and activity in three groups of athletes, diabetics and non-athletes. Dysfunction of the autonomic nervous system, especially the heart is that this disorder has a poor prognosis and is associated with increased risk of sudden death. For this purpose, 120 subjects were selected and resting heart rate and activity during and after exercise test were compared. All statistical analysis was performed using statistical software SPSS version 16 and charts were drawn using EXCEL, 2010 edition. Statistical significant level was considered less than α ≤ 0/5.Results of the research showed that in exercise test people with diabetes reach their maximum heart rate sooner and resting heart rate is also higher than the other two groups. This shows the positive effect of physical activity on vagal tone and heart rate autonomic nervous system of heart rate.