Why do I feel pain after exercise?

Have you ever felt sore after starting a new activity or pushing yourself harder than usual during a workout?

Muscle pain that shows up a day or two after exercising can affect anyone, regardless of your fitness level.

But don't be put off. This type of muscle stiffness or achiness is normal, doesn't last long, and is actually a sign of your improving fitness.

Dr Jonathan Folland, an expert in neuromuscular physiology from Loughborough University, explains how to avoid sore muscles after exercise.

Why do my muscles feel sore after exercising?

Sore muscles after physical activity, known as delayed onset muscle soreness (DOMS), can occur when you start a new exercise programme, change your exercise routine, or increase the duration or intensity of your regular workout.

When muscles are required to work harder than they're used to, or in a different way, it's believed to cause microscopic damage to the muscle fibres, resulting in muscle soreness or stiffness.

DOMS is often mistakenly believed to be caused by lactic acid build up, but lactic acid isn't involved in this process.

Who can DOMS affect?

Anyone can develop DOMS, even those who have been exercising for years, including elite athletes.

It can be alarming for people who are new to exercise, and it may dent their initial enthusiasm to get fit. The good news is that the pain will decrease as your muscles get used to the new physical demands being placed upon them.

The soreness is part of an adaptation process that leads to greater stamina and strength as the muscles recover and build. Unless you push yourself hard, you're unlikely to develop DOMS after your next exercise session.

What type of activities can cause DOMS?

Any movement you're not used to can cause DOMS – in particular, movements that cause the muscle to contract while it lengthens, called eccentric muscle contractions.

Examples of eccentric muscle contractions include going down stairs, jogging or running downhill, lowering weights (such as the lowering phase of a bicep curl), and the downward motion of squats and push-ups.

How long does DOMS last for?

DOMS typically lasts between three and five days. The pain, which can range from mild to severe, usually occurs one or two days after the exercise.

This sort of muscle pain shouldn't be confused with any kind of pain you might experience during exercise, such as the acute, sudden and sharp pain of an injury, such as muscle strains or sprains.

How can I treat DOMS?

There's no one simple way to treat DOMS. Nothing is proven to be 100% effective. Treatments such as ice packs, massage, tender-point acupressure, anti-inflammatory drugs (such as aspirin or ibuprofen), and rest may help ease some of the symptoms.

DOMS doesn't generally require medical intervention. However, seek medical advice if the pain becomes debilitating, you experience heavy swelling, or your urine becomes dark.

How can I prevent DOMS?

One of the best ways to prevent DOMS is to start any new activity programme gently and gradually. Allowing the muscle time to adapt to new movements should help minimise soreness.

There's little evidence that warming-up will be effective in preventing DOMS. But exercising with warmed-up muscles will reduce your chance of injury and improve your performance.

While stretching has many benefits, there's currently no evidence stretching before or after exercise helps reduce or prevent DOMS.

Can I continue exercising with DOMS?

You can exercise with DOMS, although it may feel uncomfortable, especially during the warm-up phase. You may find the pain goes away during the session, but returns after exercising once your muscles have cooled down.

If the pain makes it hard to exercise, it's advisable to refrain from the activity for a few days until the pain eases. Alternatively, you could focus on exercises targeting less affected muscles to allow the most affected muscle groups time to recover.

Will I keep getting DOMS?

DOMS is a type of muscle conditioning, which means your muscles are adapting to the new activity. The next time you perform the same activity, or exercise at the same intensity, there'll be less muscle tissue damage, less soreness, and a faster recovery.

Just one bout of DOMS actually develops a partially protective effect that reduces the chances of developing soreness in that same activity for the following weeks or months.