Rope jumping is a vigorous and demanding exercise. You can run, walk or pedal as slowly as you want, but when you jump rope, you have to spin the rope at least 80 times a minute to keep it taut and untangled. Jumping 80 times a minute is like running a mile in 7 minutes and 20 seconds. Most people can't exercise that intensely.
If you're in good shape, you can jump rope in your home without expensive equipment. To fit the rope to your body, place one rope handle under one armpit. Stand on the rope and pull it tight. The other handle should just reach your other armpit.
When you jump rope, you hit the ground with significant force. To protect yourself from an injury, you have to learn how to use your knees as a spring to absorb the shock. Push off from your toes and land on the balls of your feet with your knees bent, bending your knees further on impact to absorb the shock.
Do not jump more than an inch off the ground. The rope will return to the ground in less than three-quarters of a second. If you jump too high, you'll be hanging in the air when the rope returns to the ground. Since your knees are bent, your upper body has to lean slightly forward to balance your center of gravity. If you can get the rhythm jump for several minutes, you can get a very intense workout.
Q: I'm trying to lose weight and am exercising faithfully. Will drinking a lot of water help me? -- D.P., Abilene, Texas
A: You should drink enough water to keep from getting dehydrated while you work out, but water won't cause you to eat less food. Drinking a lot of water with your meals fills up your stomach, but only for a minute or two. As soon as the water leaves your stomach, you will feel hungry again. You stop eating when the calories from the food that you eat signal your brain that you have had enough. Water contains no calories, so drinking water will not help you toeat less food throughout the day.
Your body takes water from the food that you eat. You don't have to force yourself to take in extra water. Another bit of misinformation is that you shouldn't drink water with your meals because the water dilutes the enzymes in your intestines so they can't break down food. The enzymes in your stomach and intestines are so powerful that no amount of water will dilute their effect.
Q: Are there any medications that will hasten the healing of a pulled hamstring muscle? -- T.O., Pittsburgh
A: Muscle pulls are a hazard of exercising. The only drugs that have been shown to help heal muscles are anabolic steroids and clenbutarol.
Anabolic steroids are illegal and have dangerous side effects. Clenbutarol appears to be safe in the low doses that are required to hasten muscle healing, but it has not been approved for use in the United States. It's OK to take pain medicines such as ibuprofen, but they do not speed healing. You may make matters worse if you mask the pain that warns you not to use the injured muscle.
Cortisone-type injections block pain and reduce swelling, but they may actually delay healing.
The immediate treatment for any pulled muscle is RICE: Rest, Ice, Compression and Elevation. Stop exercising immediately; apply an ice bag wrapped in a towel to the injured muscle; wrap a bandage loosely over the ice bag; and raise the injured part above the heart. Remove the ice after 15 minutes and reapply it once an hour for the first few hours after the injury occurs.
In the long term, the only effective treatment is rest. You should not exercise that muscle until you can do so without feeling pain. When you return to exercising, start out at reduced intensity and duration, working back up gradually to your normal workout. Stop immediately if you feel pain.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.