Wearing ankle weights will not help you to run faster or longer, or jump higher. Training is specific. To run faster in competition, you have to run fast in practice. Ankle weights slow you down because they interfere with your coordination and make you work much harder to raise your knees. To train your muscles so you will be able to run longer, you have to run faster or for a longer time. The heavy weights will tire you earlier so you will not be able to run as fast or as far.
Using ankle weights won’t help you to jump higher, either. To jump higher, you have to strengthen your leg muscles in the same way that you would use them to jump. When you wear ankle weights, you strengthen your leg muscles for lifting weights off the ground with your feet. When you jump, you raise your body off the ground. To help you to jump higher, you have to raise your body up against resistance. You do this by doing leg presses or squats with heavy weights on your shoulders.
Ankle weights can also increase your chances of being injured. Since they force you to lift a much heavier weight when you raise your knees, they strengthen the quadriceps muscles in the front of your upper leg without strengthening the hamstrings in the back equally. This can make your quad muscle proportionately so much stronger than your hamstrings that you are prone to injury. The same principles apply to carrying weights when you walk or run, or wearing weighted belts or other devices. Strength training should be done using weights with proper form in specific exercises, and should be kept separate from your aerobic activities.
Dear Dr. Mirkin: I’m always tired after I exercise. Would potassium supplements help me?
Tiredness and cramps in athletes can have many causes, but lack of potassium in their diets is not one of them. Many years ago, Dave Costill of Ball State University tried to create potassium deficiency in runners. He couldn’t do it because potassium is found in all foods except refined sugar, and his athletes would not stay on a diet that consisted only of hard candy.
The kidneys and sweat glands conserve potassium so well that you don’t lose much. If an athlete develops potassium deficiency, it’s caused by drugs, such as diuretics or corticosteroids, or by diarrhea or repeated vomiting. Some people try to control their weight by making themselves vomit after eating. This is called bulimia, and the person almost always denies vomiting. Their physicians can prove that they are vomiting by ordering blood and urine tests. If blood levels of potassium are low and urine levels are high, vomiting is the likely cause. Bulimia is a life-threatening practice, a message that needs more attention in the media.
Dear Dr. Mirkin: Can eye exercises improve my vision enough that I will be able to get rid of my glasses?
Eye exercises do not correct vision in people who are near-sighted or far-sighted, despite the advertising claims we hear every day. In 1891, a New York physician named William Horatio Bates developed a series of eye exercises to cure near- sightedness. He believed that the lens never changes shape and that most eye defects are caused by stress, which tightens eye muscles. He claimed that his exercises could cure near- sightedness, far-sightedness, cataracts, and glaucoma. He advised patients to cover their eyes with the palms of their hands, to look at different objects continually instead of staring at one thing, and to read under difficult conditions such as in dim light. He also recommended staring directly at the sun, which is terrible advice because it can damage your eyes.
Now we know that most vision problems are caused by the improper bending of light rays by the lens of the eye. The lens normally changes shape to bend light at an angle that will strike the retina and bring objects into focus. Once the lens loses its ability to change shape, you become near- or far-sighted. In near-sightedness, light rays that enter the eye fall short of the retina, causing the patient to see nearby objects only. In far- sightedness, the opposite happens. Light rays go beyond the retina, putting far objects in focus. Eye exercises are useless for near-sightedness, far-sightedness, glaucoma or cataracts. They may help people with weak eye muscles that cause eye coordination or focus problems, double vision, or even crossed, turned or lazy eyes. Before you spend money on programs that claim exercises will improve your vision, get a diagnosis from a qualified optometrist or ophthalmologist to see if you have any of these conditions.
Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., and his wife, nutritionist Diana Mirkin bring you news and tips for your healthful lifestyle. A practicing physician for 50 years more
The Good Food Book
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