Exercise

Running

How quickly will it make a difference? After two to three weeks if running three or more times a week.

How many calories does it burn? Around 612 per hour if you run six miles per hour (a 10-minute mile). You will burn more calories running off-road as your legs have to work harder on soft ground.

Will it keep me motivated? Treadmill running, hamster fashion, can be tedious: run outside, changing your route and terrain whenever you can. As you get fitter, challenge yourself more by entering fun runs.

Specific benefits: The basic running action strengthens the hamstring, quadriceps, iliopsoas muscles at the front of the hips, calf and the gluteus maximus muscles each time you take a stride forward. The pumping action of your arms will strengthen the upper body to some extent. And it's among the best forms of aerobic exercise.

Risk factors: Your feet absorb three to four times your body weight every time they strike the ground and a shock reverberates up through your legs and into your spine. Good shoes help to cushion the blow and reduce the risk of injury to the knees and other joints.

http://www.guardian.co.uk/lifeandstyle/2007/mar/06/healthandwellbeing.health