Why do my muscles ache when I’m ill?

Wondering why your muscles ache when you're coming down with something, and whether it's okay to train like this? Nick Beer has this advice

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When we become ill, our body produces white blood cells and antibodies to fight the cold or flu-like symptoms. This process requires a large amount of energy that can leave the body feeling tired.


A common symptom is aching joints and muscles. Body aches can vary in intensity and frequency. They may feel like sharp, intermittent pains or a dull persistent ache. This is partly due to our immune system having to work incredibly hard to fight off the virus that has penetrated the body. Our white blood cells are typically used to repair the muscle fibres and joints and to keep them healthy. However, when we’re ill, they’re diverted to fight the infection. Our muscles quickly lose their strength and become more fatigued. This results in them becoming sore, weak and exhausted, so it’s very important to take sufficient rest to restore our energy and regain strength.

Training while your body is fighting an infection can be detrimental to your health and overall performance. Trying to sustain a training routine will only add more stress and increase the demands on an already maxed-out immune system. Focus on keeping hydrated, eating healthily and being patient, and you’ll be back to full training in no time.


Nick Beer is a sports injury rehab specialist and development coach. Nick now specialises in strength and conditioning work

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