Exercise

Weights

How quickly will it make a difference? After the first session, your muscles will feel more toned, but noticeable changes will take three to four weeks.

How many calories does it burn? 136-340 per hour depending on weight lifted and the recovery time between repetitions and sets.

Will it keep me motivated? If improved body tone is your solitary goal, then yes. But otherwise it can become tedious.

Specific benefits Great for improving muscle tone and bone density. Combined with aerobic exercise, resistance and weight training has been shown to speed up the rate at which calories are burned, thereby resulting in quicker weight loss.

Risk factors Lift too heavy weights too often and you can get bulky. Injuries are high in the weight room, but mostly linked to weights being dropped and poor technique.

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