Stretching is not a legitimate means of cooling down. It is only part of the process. After you have completed your workout, the best way to reduce muscle fatigue and soreness (caused by the production of lactic acid from your maximal or near-maximal muscle exertion) is to perform a light warm-down . This warm-down is similar to the second half of your warm-up (but in the reverse order).

Ideally, you should start your warm-down with about 10-20 minutes of sport-specific activity (perhaps only a little more intense than in your warm-up). In reality however, you may not always have 10-20 minutes to spare at the end of your workout. You should, however, attempt to perform at least 5 minutes of sport-specific activity in this case. The sport-specific activity should immediately be followed by stretching: First perform some light dynamic stretches until your heart rate slows down to its normal rate, then perform some static stretches (see page on stretching techniques). Sport-specific activity, followed by stretching, can reduce cramping, tightening, and soreness in fatigued muscles and will make you feel better. Light warm-down exercise immediately following maximal exertion is a better way of clearing lactic acid from the blood than complete rest. Furthermore, if you are still sore the next day, a light warm-up or warm-down is a good way to reduce lingering muscle tightness and soreness even when not performed immediately after a workout.

Many people are unaware of the beneficial role that massage can play in both strength training and flexibility training. Massaging a muscle, or group of muscles, immediately prior to or after performing stretching or strength exercises for those muscles, has many beneficial effects (see page on Sports Massage)

Ideally, a particular stretch should work only the muscles you are trying to stretch. Isolating the muscles worked by a given stretch means that you do not have to worry about having to overcome the resistance offered by more than one group of muscles. In general, the fewer muscles you try to stretch at once, the better. For example, you are better off trying to stretch one hamstring at a time than both hamstrings at once. By isolating the muscle you are stretching, you experience resistance from fewer muscle groups, which gives you greater control over the stretch and allows you to more easily change its intensity.

Having leverage during a stretch means having sufficient control over how intense the stretch becomes, and how fast. If you have good leverage, not only are you better able to achieve the desired intensity of the stretch, but also you do not need to apply as much force to your outstretched limb in order to effectively increase the intensity of the stretch. This gives you greater control.

Although a stretch may be very effective in terms of providing the athlete with ample leverage and isolation, the potential risk of injury from performing the stretch must be taken into consideration.

Even an exercise offering great leverage and isolation may be a candidate for the discard pile -- because many otherwise good stretches subject joints to potentially injurious stresses. Some of these exercises may involve rotations that can strain ligaments or tendons. Others put pressure on vertebral disks and can lead to lower back problems (like the classic backbend exercise). Still others call for twists or turns that can cause problems in areas unrelated to the stretch.

Duration, Counting, and Repetition

Some controversy surrounds how long a stretch should be held. Some researchers say 30-60 seconds; more recent research on the hamstrings indicates that 15 seconds may be sufficient. Whether the 15 seconds that may be sufficient for the hamstrings is also sufficient for other muscle groups is unclear.

A good common ground seems to be about 20 seconds. Children, and people whose bones are still growing, do not need to hold a passive stretch this long (and, in fact, some books strongly discourage it). Holding the stretch for about 7-10 seconds should be sufficient for this younger group of people.

A number of people like to count (either out loud or to themselves) while they stretch. While counting during a stretch is not, by itself, particularly important ... what is important is the setting of a definite goal for each stretching exercise performed. Counting during a stretch helps many people achieve this goal.