Purpose

During moderate-to-high intensity exercise, your body undergoes a number of changes, including increased heart and respiration rates, heavier sweating and increased blood flow. The purpose of cool down exercises is to help your body ease back into its pre-exercise state with minimal stress. Your breathing slows, pulse will return to normal and your core temperature will drop. Cooling down may also begin the repair process for achy and tired muscles, allowing the lactic acid that has built up in your body during activity to gradually dissipate without causing discomfort. Some athletes notice a reduction in post-exercise soreness after a cooldown. However, as shown in studies published in "The Journal of Strength and Conditioning Research," cooling down does not affect recovery in everyone.

Strategy

The first step of a cool down exercise session is to continue what you are doing - jogging, walking, or swimming, for example -- but at a reduced pace. For most casual, non-professional athletes a five to 10-minute cool down is sufficient to help your muscles and the rest of your body transition back to a resting state. Professional athletes who train at much higher intensities and for longer hours require a longer cool down period too. Twenty minutes to a half hour of cooling off activity may be needed.

Stretching

Cool down stretching after the main part of your workout contributes to flexibility and relaxation of the muscles. You can perform the same types of stretches that you use as a warm-up before exercising, such as range-of-motion exercises for your neck, shoulders, knees, ankles and wrists. Quadricep and calf stretches help your lower body relax. Extend your arms in front of you with clasped hands to stretch your shoulders and upper back, then clasp your hands together behind your back to stretch out your chest.

Breathing

Deep breathing can be an effective way to cool down and oxygenate your body. Breathing exercises can be performed while you stretch the rest of your body or as you sit quietly. Focus on each inhalation and exhalation and keeping your breathing even.