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
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The most common cause of muscle cramps in exercisers is lack of salt, according to a report from the University of Oklahoma (Sports Medicine, April-May 2007). The authors cite studies of tennis and football players showing that crampers tend to be salty sweaters, and of triathletes who cramp losing more salt during a race than peers who did not cramp. They found that intravenous saline can reverse cramping, and that more salt in the diet or in sports drinks can help to prevent heat cramping.
Until now, the leading theory was that most cases of muscle cramps in competitive athletes are caused by an exaggerated “stretch reflex”. When you stretch a muscle, it pulls on its tendon. Stretch reflex nerves in that tendon send a message back to the spinal cord (not the brain), and then the “stretch reflex” in the spinal cord sends a message along nerves from the spine to cause the muscle to contract. During fatigue, the muscle retains its contraction to form a cramp. A study from South Africa showed that the most likely cause is muscle fatigue or tearing of the muscle itself. If this is true, muscle cramps during endurance events can be prevented by slowing down when you feel excessive soreness in one muscle group or straining in a muscle. Of course, competitive athletes will not do this, and they pay for it with muscle cramps.
For many years I have recommended eating salted peanuts or other salty foods during heavy exercise, but other doctors believe that extra salt will raise blood pressure. If this is a concern for you, get a wrist cuff monitor and check your blood pressure every day. You are likely to find that your blood pressure goes down, not up, with regular exercise even when you add salt.
Dear Dr. Mirkin: Do different finger lengths have any significance?
High levels of the male hormone, testosterone, cause the fourth finger of unborn children to grow more than the second. This explains why men usually have proportionately longer fourth fingers than women do. Scientists can use the length of the fourth finger to tell which women were exposed to higher levels of testosterone before they were born. Researchers at the University of Central Lancashire in Preston, England showed that women whose fourth finger is much longer than their second were faster cross country runners in races of one to four miles (American Journal of Human Biology, May- June 2007). The finger length was measured from the bottom crease where the finger joins the hand to the tip of the finger. Men are typically bigger and stronger than women, and have larger muscles and bones, because of their higher testosterone levels. Testosterone helps people to recover faster from hard workouts, so they can do more work and become better athletes. Women exposed to higher levels of testosterone in utero have higher ratios of their fourth to second fingers and often are better athletes.
Dear Dr. Mirkin: Can acne be treated by avoiding specific foods?
Most dermatologists tell their patients that diet has nothing to do with acne, but researchers at RMIT University in Melbourne, Australia presented a paper showing that an experimental low glycemic–load diet helps to improve acne (American Journal of Clinical Nutrition, July 2007). After 12 weeks, those on the special diet had lower acne lesion counts, lower body weight and lower blood levels of male hormones, compared to those who were not on the special diet.
Acne is a skin disease in which a person’s skin glands produce excessive amounts of oil that is converted from a colorless liquid to a more solid white sebum. Then the body causes an immune reaction that causes redness and swelling around the oil glands on the surface of the skin. High levels of male hormones increase oil secretion, while female hormones usually lower it. This study shows that foods that cause a high rise in blood sugar may increase male hormones, oil production and acne.