Forget the vanity associated with your abs. The muscles with the most upside for runners are your hip muscles, according to new research out of Canada.

After reviewing over 20 years worth of previously published studies, the scientists concluded that weakness in a runner's hip muscles significantly increase their risk of chronic knee pain, shin splints, Achilles tendonitis and pain in the sole of the foot.

"The hip muscles are responsible for stabilizing the leg during running," explained lead researcher Dr. Reed Ferber, M.D., of the University of Calgary. "If these muscles are weak or become fatigued easily, there is less control of the leg and the risk of injury increases."

If your hip abductors (on the outside of your hip) are weak, your knees will then roll too far inward with each running stride, increasing the risk for patellofemoral pain syndrome, which causes pain under and around the kneecap. Or, iliotibial band syndrome, where pain arises in the outside of the knee. Of the 70 percent of runners who suffer an overuse injury each year, about half of those injuries occur in the knee.

The good news: Ferber found that just six weeks of hip-muscle training can alleviate pain from various running injuries in most patients, while building up protection from future injuries.

© Core Performance

Abbott Nutrition strongly recommends that you consult with your physician before beginning any exercise program and perform exercises under the supervision of a certified fitness trainer or conditioning coach. The effect of any specific exercise on a medical condition should be determined by your health care professional. The suggestions here are in no way intended to substitute for medical advice.