Dr. Wayne Phillips, Chief Science Officer of MuscleSound – Soreness happens not only to first time exercisers, but also can affect athletes and regular exercisers if they increase the intensity and/or duration of their workout significantly more than their normal routine. The muscle soreness we feel after exercise is a signal that we have exercised in a way our muscles aren’t used to.
Muscle soreness is a sign of microscopic damage and swelling that occurs in the sarcomere—the smallest contractile unit of a muscle. This damage is predominantly caused by what are called ‘eccentric’ muscle contractions, where the muscle is working as it lengthens. For example, running, and especially downhill running, is a major source of eccentric contractions since the leg muscles work very hard to slow and/or control the downward descent of the body. Heavy weight lifting can also produce high levels of eccentric contractions since after the bar is lifted it needs to be lowered under control with each repetition of a set. Since this kind of soreness typically does not peak until some time after the end of exercise, it is known as Delayed Onset Muscle Soreness or DOMS.
How long can people expect to be sore?
DOMS begins fairly soon after exercise and typically peaks between 24 and 72 hours. It has generally dissipated within 6 - 7 days depending on the mode, intensity and duration of exercise, as well as the fitness status of the performer. While the soreness is delayed and can range from mild to debilitating pain, DOMS also produces immediate weakness in the affected muscle that generally lasts a similar length of time to the soreness. DOMS can also produce swelling, tense muscles, reduced coordination and a limited range of range in of motion.
In general, time is the only dependable healer for DOMS. While few preventive strategies have so far been discovered, a number of approaches have been proposed to treat or minimize the effect of DOMS. These can be categorized as physiological, mechanical and nutritional:
As its name implies, an initial bout of eccentric exercise reduces the impact of DOMS in future bouts. So, for example, an initial session of downhill running would produce significant DOMS. However, a second, similar, downhill run would produce far less DOMS, and this adaptation would continue to reduce muscle soreness over several sessions. A similar affect occurs in weight training, as long as the initial lifts were at or close to maximum. Studies have shown that working at 50% of a maximal eccentric load did not provide protection against a subsequent maximal bout. The repeated bout effect is by far the most effective method of ‘preventing’ DOMS. Easy paced exercise such as walking, jogging or cycling is generally accepted as an effective method of reducing DOMS. However the reduction in discomfort is temporary and disappears soon after the exercise has ended.
Some research has suggested that post-exercise massage and/foam rolling soon after exercise can help reduce DOMS. The mechanisms of this are unclear, though it may be related to a physical ‘flushing out’ of the edema-related fluid in the muscle. Also, the benefit appears to be only related to soreness with no impact on DOMS-related muscle weakness. One potential obstacle to this approach is that on occasion DOMS-effected muscles can be tender to the touch and massage would be contra-indicated.
Compression garments are typically associated with medical and/or therapeutic treatments. More recently however, they have been studied for the relief of DOMS. Research has shown that wearing compression clothing, including both compression socks and compression tights, relieves the soreness and weakness associated with DOMS-producing exercise. A personal fitting is recommended if this approach is adopted, since the benefits of compression clothing are likely to vary with the particular garment, how well it fits and therefore the pressure that is provided. No research to date has investigated the effect on post exercise recovery of wearing compression clothing during DOMS-producing exercise.
Muscles begin to repair themselves after DOMS-related damage and an optimal nutritional approach will speed this process. Most research has shown that protein intake will reduce muscle weakness after DOMS-producing exercise. However, while carbohydrate alone has no effect on DOMS, a mixture of protein and carbohydrate in a ratio of approximately 1:3 has been shown to be far more effective than protein and carbohydrate taken separately. The timing of such mixtures is also important: they need to be taken not later than 2 hours after, and preferably immediately after, exercise for their greatest effect. Dietary intake prior to exercise has been shown to have no effect on DOMS.