What causes chafing, and why do I get it when cycling and swimming?

Suffer with chafing? Here is some treatment and prevention advice from physiotherapist Phil Burt

what is chafing and how to treat it

Chafing is an issue of friction. It occurs frequently in areas of the body where the skin has to deal with large amplitudes of frequent movement, and is common in triathletes and cyclists due to the repetitive nature of pedalling, which causes friction at the interface of the saddle and groin/top of thigh/undercarriage. The forces from the cycling short or tri-suit moving across the skin under tension from the saddle cause the skin to become irritated. In triathletes the same issue can occur at the armpit while swimming. The cause is nearly always a combination of position, equipment, fit and skin vulnerability. 

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For armpit chafing, the solutions are relatively straightforward. Make sure your skinsuit, tri-suit or wetsuit is allowing free movement without feeling too tight, which increases the frictional load. You can also manage the skin/suit interface by applying a lubricant. Use a product that has a good emollient quality. This is its slippiness and reduces the frictional load across the skin.

Saddle chafing is somewhat more multifactorial. Again, correctly fitting kit is important –shorts that aren’t too tight or loose so the material rucks up in the groin. However, the position, width and shape of the saddle is also key. Often, too wide a saddle will lead to chafing, but if a saddle is set too far forward this can force you to sit in the wrong place and mimic a width issue. A classic mistake is to use a spilt-nose TT saddle on a road bike where the front is too wide to allow a free road pedalling action.

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Again, using a good emollient or chamois cream is useful in cycling to reduce the friction between the skin and other surfaces. Some people are more vulnerable to chafing due to the type or nature of their skin health and may find they have to use creams more than other triathletes. Heat and sweat complicate things further, so what we grandly call ‘environmental management’ can help. One simple example is to use a fan when training indoors.