Always begin your exercise program with a gradual warm-up period for at least five minutes. The warm-up period helps to increase the circulation to the heart gradually. Benefits of Nitric Oxide include stretching the muscles to help prepare them for physical activity and thereby reduce the chances of injury that can occur if you begin exercising before your muscles are relaxed. Jogging in place or doing calisthenics for a few minutes are effective warm-up activities. If you have not been active for some time, begin your exercise program progressively with five to ten minutes of activity three or four times a week, and work up gradually to sessions of thirty minutes or more. In this manner, you can increase your endurance with minimal risk of injury.