I see people running with Lycra shorts under their normal shorts. Is that just a fashion thing, or is there some benefit to doing it?
Marcus Gardener, London

Matt Hart replies: In most cases it’s just a fashion thing. The argument supporting the use of Lycra shorts is that they keep the thigh and hamstring muscles warm, so they’re less likely to tear and get injured. If the weather is particularly cold or the running is intense it would be sensible to don the Lycra, but for indoor running on a treadmill or a summertime run in the park I can’t see any benefit. If you warm up progressively and regularly stretch your lower limbs you should be fine.