Light weights on your arms or legs can boost your exercise benefit.
Some people carry light (one- or two-pound) hand-held weights when they walk or run. Others strap velcro-fastened weights around their ankles. Dont bother, says exercise physiologist Ben Hurley of the University of Maryland.
It slows you down, so you get less benefit from aerobic exercise, and it doesnt add enough weight to give you the benefits of strength-training, he explains.
To build muscle, you have to use weights that you can lift no more than eight to 12 times in a row. If you can go beyond the twelfth repetition, the resistance is too light to stress the muscle, says Hurley. As your muscles get stronger, you need to add more weight or other resistance so you can still do only eight to 12 repetitions.
Illustrations: Loel Barr