Series of Myths: Muscle Soreness - What's Fact, What's Fiction?

Muscle soreness seems to go hand in hand with exercise and physical activity. Most people expect to feel some sort of pain following a good workout session, and others avoid exercise altogether because of the soreness that will most likely ensue. However, few regular exercisers know what soreness really is, what it's caused by, and how to avoid it. Prepare to be enlightened.

The muscle soreness you feel following a workout is most likely what the scientific community has termed Delayed Onset Muscle Soreness (DOMS). You may have heard of this term. DOMS is experienced as pain and inflammation in the muscles, decreased range of motion, and decreased strength of the affected muscles. It can be felt within 8-12 hours following exercise and last 24-72 hours. In fact, complete recovery may sometimes take up to 3 weeks. DOMS is most closely associated with eccentric muscle contractions (the breaking or decelerating type of contraction--picture downhill running) or exercises that one is unaccustomed to. This type of muscle soreness is generally caused by a sequence of events beginning with damage to the muscle structure, accumulation of calcium, release of intracellular proteins, and inflammation that activates the pain receptors. There are plenty of complex chemical reactions that occur following exercise and subsequent tissue damage, and any of these reactions can have some effect on soreness.

A common myth associated with soreness is that lactic acid buildup is a cause. Muscle and blood lactate levels actually return to normal levels 30-60 minutes after exercise. (If light activity is performed, lactic acid is removed much quicker.) So if soreness is typically felt 8-12 hours following the workout, then lactic acid is not to blame. It's already gone. Furthermore, the biggest culprit of severe soreness is eccentric contractions such as those done by the muscles when running downhill. Studies have shown that running downhill produces less lactate than on flat ground. So if you're more sore after running downhill, but you formed less lactate, then lactic acid is not the cause.

Another common myth is that if you're not sore after a workout, then it's not working anymore. This is not true, because there are definite ways to reduce the occurence of DOMS. Performing a thorough warm-up prior to activity has been shown to significantly reduce soreness because it increases overall muscle function. Another way to reduce soreness is to gradually allow the muscles to adapt to the stress rather than jumping right into it. Finally, by performing more bouts of eccentric exercise the muscles will adapt to it and will be strong enough to handle the loads. For example, if you perform more bouts of downhill running your muscles will adapt and no longer respond with soreness.

However, we must address the fact that one of the causes of DOMS is unaccustomed exercise. It is well known that changing your routine often and adding variety is important for progressing and seeing continued benefits. So, these various changes may cause necessary soreness. But if you don't feel sore even though you are on a well-designed and periodized program, it may be that you are just easing into it well enough and warming-up sufficiently to prevent soreness. It doesn't mean it's not working.

Every body is different. Because soreness is a result of many variables, chemical and mechanical, it will be experienced so differently from person to person. Chronic soreness can be a predictor of overtraining, but most people should not judge the effectiveness of their training program by whether they are sore or not. Be sure to be following a program that progresses, uses many multi-joint exercises to challenge all the muscle groups of your body, and provides variety and interest. If you are doing this, soreness my occur, but now you will know why...