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Caffeine Helps in Sprints and Endurance Events

It has been established for more than 50 years that caffeine helps you exercise longer in events that require endurance. Recently researchers at Christ Church University in Canterbury, UK, showed that caffeine also helps you in much shorter events. Trained cyclists raced one kilometer (0.6 mile) on three times, in random order, after taking 5 mg of caffeine, taking a placebo, or taking nothing. Their speed, mean power and peak power were more than three percent higher after taking caffeine (Journal of Sports Sciences, November 2006).

Most athletes know that caffeine improves their performance. A recent study from Griffith University in Queensland, Australia shows that 90 percent of triathletes used a caffeinated substance immediately prior to or throughout a competition (International Journal of Sport Nutrition and Exercise Metabolism, October 2006). They used cola drinks (78 percent), caffeinated gels (42 percent), coffee (37 percent), energy drinks (13 percent), and caffeine tablets (9 percent).

Caffeine increases endurance by preserving muscle sugar, causing your muscles to burn far more fat. When your muscles run out of their stored sugar (glycogen), they hurt and are difficult to coordinate. Caffeine causes your body to produce more adrenalin that moves fat from your fat stores into your bloodstream and causes your muscles to burn more of these fats. Caffeine also helps you move faster in shorter races because adrenalin makes you more alert and more aggressive.


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Dear Dr. Mirkin: How can I avoid nerve damage from my bicycle seat?

Several recent papers have shown that bicycle riders can suffer nerve damage that causes impo*tence in men and decreased pelvic sensation in both men and women. A paper from Dartmouth College shows that a rider's position on the bike may be more important than the type of seat he or she chooses (British Journal of Urology International, January 2007). Nerve damage comes from pressure on the internal pudendal nerves that travel from the sitz bones (ischial tuberosities) forward toward the center of the pelvic bones. Anything that presses on this nerve can cause permanent damage. The nose of a bicycle seat is positioned between the legs and can press on the nerve. Bending forward lowers the internal pudendal nerve on the seat to compress it between the pelvic bones and the seat. Changing to a more upright position relieves the pressure.

Dr. Steven Schrader, at the National Institute for Occupational Safety, notes that bicycle seats can cause impo*tence by blocking blood flow to the pe*nis, as well as causing nerve damage. He emphasizes that the nose of the seat is the major culprit and recommends noseless seats. However, bicycle racers and many recreational riders will not use them because they move their legs against the seat's nose to help control the bike. Seats that have holes in the middle do little to prevent compression.

Since pressing on a nerve hurts, you can usually tell when you are causing nerve damage. According to this new study, the best way to avoid nerve damage is to change positions immediately when you feel any discomfort.


Dear Dr. Mirkin: Will my muscles get stronger if I eat before a hard workout?

A study from the University of Birmingham in England shows that eating protein plus carbohydrate before and after vigorous exercise helps athletes grow larger and stronger muscles (American Journal of Physiology-Endocrinology and Metabolism, January 2007).

Many other studies have shown that eating protein and carbohydrate helps muscles recover faster. Protein is broken down by your body into its building blocks called amino acids that are then used to heal your muscles. Taking carbohydrates causes blood insulin levels to rise and insulin drives these amino acids into muscles. This study shows that it does not matter when you take in the amino acids and carbohydrates. You can eat them before, during or after exercise. All you have to do is supply the amino acids and insulin, and your muscles will do the rest.


Recipe of the Week

Salade Nicoise

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June 26th, 2013
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About the Author: Gabe Mirkin, MD

Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., brings you news and tips for your healthful lifestyle. A practicing physician for more than 50 years and a radio talk show host for 25 years, Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. He is board-certified in four specialties: Sports Medicine, Allergy and Immunology, Pediatrics and Pediatric Immunology. The Dr. Mirkin Show, his call-in show on fitness and health, was syndicated in more than 120 cities. Read More
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