Q: My muscles were very sore and stiff for several days after lifting weights. How can I prevent this and how can it be treated?

A: Muscles are actually damaged as a result of exercise that produces soreness. It used to be thought that the soreness was caused by a by-product of metabolism called lactic acid. Some years ago, researchers in exercise physiology found that instead of lactic acid being the culprit, it was actual structural damage occurring in the contractile protein of muscle cells and the connective tissue surrounding the cells.

The damage is fairly substantial in extreme levels of exertion such as running marathons. The time to repair the damage may take a good month or so in such cases. The damage occurring from a single session of moderate weight training would be rather small in comparison, though soreness may be considerable. The soreness typically lasts about 2 to 4 days, but, once the tissues are repaired, they are strengthened structurally making them less susceptible to future injury. If you delay your next lifting session until the soreness is gone, you raise the injury threshold of the muscle used.

The best means of preventing and minimizing soreness is to progress slowly into activity, particularly if it is exercise you are unaccustomed to. For example, if beginning a running program, start with short periods every other day and jog at a fairly slow pace. For a month before jogging, train and strengthen the foot, ankle, and calf muscles. These precautions reduce the damage each day, and the day off in between provides time for the small amount of damage to be repaired and the tissues toughened. If you perform a weight training exercise you have never done before, do only one set with a very moderate weight and emphasize sound technique. Most of us occasionally experience soreness when we go out and rake leaves for several hours, shovel snow, jump rope, or do any unaccustomed exercise. This happens even to very fit people. Only if you rake leaves or shovel snow at least once a week will the muscles used in performing those activities be tough enough to withstand the physical demand.

When introducing people to weight training I always have them start with a single set for the first two sessions and only then are they encouraged to progress to two sets. The soreness produced seems quite small using this technique.

To treat the symptoms, light exercise reduces the soreness while you exercise, but the symptoms quickly return shortly after. Studies show that over the counter anti inflammatory medications such as ibuprofen help relieve the soreness and promote a faster return to exercise. However, use of them beyond a several days may retard the repair of injured tissue, so limit their use.

In summary, start easy, progress slowly, and treat new forms of exercise with respect.