Muscle soreness after exercise: why DOMS happens and what helps

What happens in the muscle

DOMS is a mild form of muscle injury. The 2018 review by Hotfiel and colleagues describes ultrastructural damage to muscle cells after unfamiliar or eccentric exercise, followed by protein breakdown and a local inflammatory response. Symptoms include tenderness, stiffness, reduced force, painful restriction of movement and sometimes swelling.

The review by Cheung, Hume and Maxwell, published in 2003, listed six theories proposed over the years: lactic acid, muscle spasm, connective tissue damage, muscle damage, inflammation and enzyme efflux. Their conclusion was that a combination of two or more is the likely explanation. Lactic acid alone cannot account for pain that peaks one to three days after it has cleared.

The same review notes that DOMS is most common when people return to training after a break, or try a new type of activity. Intensity and duration matter, and eccentric actions cause damage more often and more severely than other muscle actions.

Why the second time hurts less

A single session of eccentric exercise protects the muscle against damage from the next similar session. McHugh's 2003 review calls this the repeated bout effect and describes neural, mechanical and cellular adaptations, including the addition of sarcomeres along the muscle fibre and a changed inflammatory response. The exact mechanism remains unsettled, but the practical lesson is clear.

Introduce new exercises gradually. Cheung and colleagues recommend bringing in eccentric or novel activities progressively over one or two weeks to limit the disruption. In practice, the first session of a new programme should feel easier than you think it should: one or two sets fewer, a lighter load. If you are going back to training after months off, our guide to recovery after training explains how to read your body's signals over the following days.

What relieves soreness, and what does not

The evidence varies by method.

• Stretching: the Cochrane review by Herbert, de Noronha and Kamper pooled 12 studies. Stretching before, after, or both reduced soreness by about one point on a 100-point scale the next day, and by four points in the largest trial. The authors concluded it produces no clinically important reduction. Stretch for flexibility if you like, not for DOMS; our mobility exercises guide covers that goal.
• Massage: the 2018 meta-analysis by Dupuy and colleagues, covering 99 studies, found that massage was the most effective technique for reducing DOMS and perceived fatigue.
• Other methods: in the same analysis, active recovery, compression garments, water immersion, contrast baths and cryotherapy produced small to large reductions in soreness. Cheung's earlier review had found no effect for several of these, which shows how uncertain the field remains.
• Light exercise: Cheung and colleagues describe exercise as the most effective way to relieve pain during DOMS, but the effect is temporary.
• Anti-inflammatory drugs: the same review reports dose-dependent effects. Ask a pharmacist or doctor before using them for exercise soreness.

Should you train when you are sore

Usually yes, with adjustments. Cheung and colleagues suggest reducing the intensity and duration of training for one or two days after a hard session that caused DOMS, or working the less affected body parts while the sore muscles recover. Soreness reduces range of motion and peak force, and the resulting changes in movement can place unusual stress on other tissues, which is a reason not to attempt a maximal effort on very sore muscles.

A practical rule: if the soreness fades after a few minutes of warm-up, a moderate session is fine. If it gets worse as you move, train another area or go for a walk. The calculator below gives a quick morning check across sleep, soreness, mood, pulse and motivation.

Soreness is also not a measure of progress. Muscle can grow without much of it, and a familiar programme that leaves you only mildly stiff is still working, as long as the sets are hard. Our article on how to build muscle with bodyweight explains the effort that matters.

When it is not ordinary soreness

Seek medical advice promptly if, after exercise, your urine turns dark, red or cola-coloured, you pass much less urine, or the muscles are extremely painful, swollen or weak. MedlinePlus lists these among the symptoms of rhabdomyolysis, a breakdown of muscle tissue that severe exertion can cause. Sharp pain during a movement, pain in a joint rather than a muscle, or soreness that does not improve after a week also need to be checked.

Keep training, at the right pace

The best defence against heavy DOMS is regular training: the repeated bout effect works for those who keep coming back. Never Skip Club helps with that. Build a guided session in about a minute, at the Easy level on the days after a hard one, choosing the body area that is not sore, for 20, 30 or 45 minutes. Join a crew of three to seven friends with a weekly target: the ranking rewards regularity, so a lighter session still counts if it lasts 30 minutes. Create your free account or sign in. And if you want an expert to plan your return after a break, book a coach from our network. For loads and progressions, see our dumbbell workout at home.