P20 Once A Day (£18.45 for 200ml from chemistdirect.co.uk). If you have fair skin or a family history of melanoma, consider sun protective clothing and avoid midday runs. You should also have a coffee before you go, advise dermatologists from
and maintain a reasonable pace, you still only have about 2,000 calories worth of glycogen stored in your muscles – enough to get most runners to about mile 18 or 20," he says. "As glycogen reserves are used up and fatty acid metabolism increases, your heart
