February 18th, 2011
02:31 PM ET
Every weekday, a CNNHealth expert doctor answers a viewer question. On Friday, it's Dr. Melina Jampolis, a physician nutrition specialist.
Asked by John Simmet, St. Paul, Minnesota
I am male, 55, 6 feet 5, 300 pounds. I am in good health (other than weight), active in biking and weight training but am interested in jogging. Am I too large to train for a 10K? Would that be detrimental to my joints?
Hi, John. I'm so glad that you asked this important question. Jogging is a terrific, simple and low-cost way to lose weight as it burns significantly more calories (up to 65% more) than walking or biking, but many people who are overweight or obese probably avoid it due to fear of joint injury.
I consulted with orthopedic surgeon and sports medicine specialist Dr. A Shabi Khan, who explained that biomechanical studies have never proven that running, even marathon running, promotes cartilage damage in a normal knee.
What constitutes a normal knee? It means that you have had no significant knee injury in the past and that you have no evidence, whether by X-ray, MRI or physical examination, of arthritis or cartilage damage in the knee. So even if you are overweight or obese, if you have no existing knee damage, it's OK to try jogging.
If you have evidence of arthritis in the knee, persistent or recurrent knee pain, or history of a previous knee injury, this does not necessarily mean that you can't jog at all.
Depending on the severity of your arthritis or past injury, you could consider cross training in addition to jogging to get in shape for the 10K without putting too much strain on your knee.
This could include continuing the bike and using the elliptical machine or StairMaster. In addition, make sure to continue your strength training, and focus on strengthening your quadriceps (front of the thigh), which are important for runners. The two main exercises for quadriceps include leg extensions (usually done on an exercise machine) and squats.
If you have knee problems, I highly recommend seeing a physical therapist or orthopedic surgeon for evaluation before starting a vigorous jogging training program. And of course, make sure to get medical clearance from your doctor before stepping up (no pun intended) your cardiovascular exercise regimen.
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