We all know running puts us at high risk for injury, but researchers are finding out there's a lot more behind running-related injuries than impact forces.
Specifically, it's the combination of impact and joint instability that puts running on par with tackle football when it comes to numbers of injuries.
Here's why: When your foot makes contact with the ground, your muscles and connective tissues must work together to resist the potential joint-destabilizing effect of impact.
Most runners, particularly those who do not cross-train, are weak in key stabilizing muscles. As a result, the body is forced to absorb impact in a way it's not built to handle.
"The biggest thing I see is that runners have very weak core musculature, and because of this they can't control their posture while they're running," says Michael Fredericson, M.D., a running injury expert at Stanford University.
"Their pelvis goes into a forward tilt and they get an arch in their low back." This, Fredericson, says, results in extra stress on both the hamstrings and knees.
The hips are also problematic in many runners.
"The hip abductors and external rotators of the hip tend to be weak, or they're just not firing appropriately -- they're not becoming active when they should," says Bryan Heiderscheit, P.T., Ph.D., who directs an injury clinic for runners at Des Moines University in Iowa.
"You'll end up assuming an internally rotated position at the knee and at the hip." This can cause injuries ranging from knee pain to tendonitis in the hips and groin.
Other muscles that tend to be dangerously weak in runners are those of the lower back and the front of the lower leg.
Luckily, strengthening these running stabilizers doesn't need to take a lot of extra time. Simply add another 15 minutes to your running routine twice a week (if you're really pressed for time, steal it from the time you already run -- you'll thank yourself later) and mix in the following strength exercises.
(For photo illustrations of these exercises and a lot more information about strength training for runners, see my book, Runner's World Guide to Cross-Training.)
Lower abdominal squeeze
Lay face up with your arms relaxed at your sides and your legs extended straight toward the ceiling with your heels together. Then contract the muscles of your lower abdomen and, by doing so, try to lift your heels ever so slightly toward the ceiling. (This is a very small movement).
Hold the contraction for one second, then relax for one second. Repeat the exercise until you feel a nice burning sensation in the targeted muscles.
Benefit: Strengths lower abdominals and prevents forward tilt of pelvis during running.
Stand with your side next to a 12- to 18-inch platform (such as a weight bench or tall aerobics step). Place your right food on the platform keep your left foot on the floor (your right knee is bent and your left leg is straight).
Shift your weight onto your right leg stand on that leg, lifting your entire body 12 to 18 inches.
Pause briefly with your left foot unsupported in the air next to your right foot, then bend your knee again and slowly lower your left foot back down to the floor.
Benefit: Strengthens the thighs, hips, and glutes, improving knee and hip stability.
Place a pillow on the floor and balance on it with one shoeless foot for 30 seconds, and then balance on the other foot, and repeat. At first it will be difficult to last 30 seconds, but you'll quickly improve. Keep it challenging by using a bigger or softer pillow, by stacking pillows, and/or by balancing longer.
Benefit: Strengthens the muscles that oppose the calf muscles, improving ankle stability.
Lie face up with your arms resting at your sides and your palms flat on the floor. Extend your legs directly toward the ceiling, keeping your feet together, and point your toes.
Keeping your big toes side-by-side, tip your legs 12 to 18 inches to the right by twisting at the hip, so that your left buttock comes off the floor. Fight the pull of gravity by maintaining stability with your abs and obliques.
Pause for a moment, then return slowly to the start position, again using your core muscles to control the movement. Repeat on the left side. Do 8-12 repetitions on each side.
Benefit: Strengthens the abdominal muscles, including the obliques, improving pelvic stability.
Single arm dumbbell clean and press
Assume a wide athletic stance with a single dumbbell placed on the floor between your feet. Begin with your left arm fully extended and bend forward from the hips and grasp the dumbbell with your left hand.
With a single, fluid, powerful movement, pull the dumbbell off the floor, stand fully upright, and continue raising your left arm until it is extended straight overhead.
Pause briefly and then reverse the movement, allowing the dumbbell to come to rest again on the floor briefly before initiating the next lift. Complete 10-12 repetitions and then switch to the right arm.
Benefit: Strengthens the thighs, hips, glutes, lower and upper back, chest, and shoulders, improving knee and hip stability and running posture.Part 1: Intro to cross-training Part 3: Stretching Part 4: Non-impact cardio training Part 5: Form training Part 6: Shoe and foot science
Matt Fitzgerald coaches runners and triathletes and is the author of "Triathlete Magazine's Complete Triathlon Book" and "Runner's World Guide to Cross-Training."