Experienced bicycle riders know that fatigue comes from how hard you press on the pedals, not how fast you turn them. Novice racers may try to ride with maximum force on the pedals, but they quickly exhaust themselves and often can't even finish the race. Cycling is a power sport. The number of times you spin your bicycle pedals in a minute is called your cadence, and your power is the product of the force that your feet apply to the pedals time your cadence. A study from Ithaca College in New York shows that a very high cadence does not help in shorter races (International Journal of Sports Medicine, Volume 26, 2006).

Competitive cyclists were asked to ride a 5-mile time trial at their usual fast cadence. For most racers, this is more than 90 rotations per minute. They then rode a second 5-mile time trial at a 10 percent lower cadence and a third trial with a 10 percent increase. The riders raced far faster at the 10 percent reduced cadence. A study from Toledo, Spain also shows that spinning the pedals too fast slows you down (Medicine and Science in Sports and Exercise, May 2006).

Most bicycle riders do best when they chose gears that allow them to pedal at a cadence of 80 to 90. You want to pedal as fast as you can with the greatest force you can maintain on your pedals, but if you spin too fast, your brain cannot coordinate your muscles so you lose efficiency. Try to choose a gear ratio that allows you to spin as fast as you can and still feel some pressure on your pedals. If you have to push on your pedals so hard that your body moves from side to side, you need to reduce the gear ratio and pedal faster. If you are spinning faster than 100 times a minute, you are probably losing coordination. Bicycle computers that show your cadence are available in bike shops and online bicycle catalogs. When you are going out on a long ride, try to keep a comfortable fast cadence. However, if you are going to sprint or race for less than 30 minutes, you will ride faster by putting more pressure than usual on you pedals, which will slow your cadence by about 10 percent. You can also use this technique to pick up the pace when you want to catch up with another rider.

Gabe Mirkin, M.D.

Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in Sports Medicine and three other specialties.

Dr. Mirkin's daily features on fitness have been heard on CBS Radio News stations since the 1970's. He has written 16 books including The Sportsmedicine Book, the best-selling book on the subject that has been translated into many languages. His latest book is The Healthy Heart Miracle, published by HarperCollins.

Dr. Mirkin is a graduate of Harvard University and Baylor University College of Medicine. A Boston native, Dr. Mirkin did his residency at the Massachusetts General Hospital. He has served as a Teaching Fellow at Johns Hopkins Medical School, Assistant Professor at the University of Maryland, and Associate Clinical Professor in Pediatrics at the Georgetown University School of Medicine. He has run more than forty marathons and is now a serious tandem bicycle rider with his wife, nutritionist Diana Mirkin.