Getting on a bike exercises the heart and lungs more than walking and avoids the impact of running. Although cycling on busy roads means you will be breathing in pollution. For best results, cycle for a 20-30 minutes, three or more times a week in fresh air. Helps maintain and build bone mass in the lower body but upper body will need weights work. Cycling burns 400 calories an hour on the flat and more on hills. It also tightens bottom, thighs and calves. There’s a risk of bulking up muscle (particularly the calves), so it may not be the best choice for a leaner, sleeker look. Upper body gets only a minimal workout. It does shorten the muscles so should be combined with Pilates or yoga. In research, adults who improved their fitness by 15 per cent through cycling also raised their scores in a memory test because cycling improves blood flow to the brain.