Gabe Mirkin, M.D.
The only advantage to exercising while carrying weights
is that you can get more exercise while moving slowly. To
strengthen your heart, you have to exercise vigorously enough to
increase your heart rate at least 20 beats a minute above resting.
How fast your heart beats depends on how much blood it has to
pump to your body. When you run and carry hand weights, your
heart has to pump blood to your exercising leg muscles and also
has to do extra work to pump blood to your arm muscles. That
means that you can achieve the same heart rate when you run
more slowly.
Competitive runners should never carry hand weights.
How fast you run in races depends on how fast you run in
practice. Carrying hand weights slows you down, so you become
a slower runner. Carrying weights also interferes with the natural
motion of your arms while running. On the other hand, carrying
weights can help to protect people who develop frequent running
injuries. Carrying hand weights slows them down, so less force is
directed at their leg muscles while they run. Hand weights will not
do much to increase your arm strength; to become stronger, you
must lift progressively heavier weights.
June 15, 2006