Every time you take a step, you put three to seven times the weight of your
body on your joints. Take that same step in water, and the natural buoyancy of
H2O gently lifts the pressure off your joints, while still allowing
you to work your muscles.
In every issue of WebMD the Magazine, we ask experts to answer readers' questions about a wide range of topics, including some of the oldest -- and most cherished -- medical myths out there. For our October 2011 issue, we asked Dimitrios Pappas, MD, assistant professor of medicine at Columbia University's College of Physicians and Surgeons, about the long-term effects of one popular childhood activity: knuckle cracking.
Q: My 10-year-old son cracks his knuckles. Is it true that it causes arthritis?
Stand in water that's about waist high or a little deeper -- just
as long as you're able to plant your feet on the bottom -- and hold your arms
out to your sides for balance. Put your left foot in front of your right. Raise
and bend your left knee. Then hop forward, pushing off with your right foot,
landing on the left foot. Do it again, keeping the heel of the right foot up,
pushing off with the toes and ball of the foot. Do this several
If you were to do this on dry land, the impact of landing would jar your
joints, making you wince and holler, notes Bernard Rubin, chief of rheumatology
at the University of Texas Health Sciences Center. In the water, however, the
landing is soft because the water slows you down and buoys you up.
Nevertheless, you're giving your leg muscles a good workout and you're
increasing your heart rate.
During exercise, you should raise your heart rate to 50-75% of your maximum
heart rate. Your maximum heart rate is your age subtracted from the number 220.
So, if you're 60, your maximum heart rate is 160 beats per minute. If you
haven't worked out in a long time, stay around 50% of your maximum while
exercising: That's 80 beats per minute. After you've been exercising regularly
for a while, try getting it up to 120 beats per minute, which is 75% of the
If possible, exercise in warm water, which will help ease pain in your
joints and relax your muscles. Some people may want to do exercises while
sitting in a hot tub or spa. If you don't want to buy one, you can join a
health club that has one. Be sure to talk with your doctor before exercising in
a hot tub. Warm water can cause problems for people with other medical
problems, including high blood pressure.
To begin water exercises, contact The Arthritis Foundation or your local
recreation center for a program near you. Many local YMCA, YWCA, or community
centers offer pool exercise classes designed especially for people with
arthritis. If you have a pool at home, you can buy tapes and books that teach
you various water workout programs to do on your own. The Arthritis Foundation
will send you a free booklet on water exercise, which you can order from their
Web site (www.arthritis.org).