Black toenails
Black toenails – worn like a badge of honour among runners – are the result of bruising and blood blisters under the nail. These are normally caused by your toes repeatedly hitting the front of your shoe because the shoe is too tight or has an insufficient toe box, or because the end of the toes are rubbing against a sock seam, or because the toenails are simply too long. Running downhill, which causes the feet to ‘jam’ into the toe box, can also be a contributing factor.

If a black toenail just looks ugly and doesn’t hurt, leave it alone. It will either grow out or, more likely, fall off. If, however, there is a soreness and pressure behind the nail, then you may need to have the blood blister drained by a podiatrist or doctor. Some runners use foam toe protectors (rather like a soft thimble that goes over the toe) to protect from bruising but the most important thing is to address the fit of your shoes. And if you do end up nail-less just before sandal season, you can get a nail salon to apply an acrylic false nail while your real one grows back!

Sweat rash
A sweat rash under your arms, under or between the breasts or in the groin area is an unpleasant – but surprisingly common – running affliction. Minimise the risk by always showering immediately after running, not wearing fresh kit and by using petroleum jelly to prevent chafing. Tea tree oil is a natural anti-fungal agent and many shower, bath and body products contain it. If you do get a rash, treat it with an anti-fungal lotion or cream – preferably one combined with hydrocortisone to reduce redness and itching.