By Adam Hodges
Core strength is a term frequently bandied about, often conjuring up images of sit-ups and crunches in pursuit of an aesthetically desirable “six-pack.” Yet core strength for runners has little to do with the aesthetic goals of body builders and everything to do with running economy and injury prevention. This article explains what a strong core means for runners, shows you how to test for one element of a weak core, and illustrates an exercise to overcome that weakness.
Running is a sagittal plane activity, meaning you move forward and backward through space. Flexors and extensors (such as the well-known hamstrings and quadriceps) act as primary movers to propel you forward toward the finish line. Yet running also requires recruitment of muscles that operate in the frontal plane—namely, the hip abductors (gluteus medius, gluteus minimus) and the hip external rotators—which act to maintain core postural control so you can move forward effectively and efficiently.
Runners with weak hips are easy to spot from behind as you’ll notice an inability to maintain level hips throughout the running stride. During foot plant, instead of the right and left hips remaining level, one of the hips drops. The dropped hip will be on the opposite side of the body of the planted foot. So during a right foot plant, the left hip drops—and vice versa.
This is because when the right foot is planted on the ground with the left foot raised off the ground, the left side of the body is cantilevered over to that side. Like a deck of a house cantilevered out over a river without any structural support directly beneath it (think Frank Lloyd Wright’s “Fallingwater”), support to hold up that deck (or that side of your body) must come from the non-cantilevered side. In the case of your body in motion, when your right foot is planted the stabilizing muscles in your right hip (gluteus medius and gluteus minimus) do the work of holding up the left side of your body.
Here’s a simple test to check the strength of your hip abductors. Find a full length mirror. Stand on your right leg. Lift your left leg off the ground. What happens to your left hip? Does the left hip drop? Do you lean your upper body to the right side to compensate (which can raise your left hip in the process)? Does your right knee dive inward? If you experience any of these results, this is a sign that your right hip abductors are weak or not properly firing.
Here’s a basic exercise you can do to address that weakness:
Lying Hip Abductions
Also commonly referred to as “Jane Fondas” or side leg raises, you can quickly and easily perform this exercise at home in a few minutes.
Lie on your right side. Stack the left foot on top of the right foot. Dorsiflex and slightly pigeon toe the left foot (this is the position to keep your foot in for the leg raises).
Now squeeze the left hip muscle (gluteus medius) to raise the left leg as high as you can. Lower the leg back down in a controlled manner. Repeat.
Perform 1-3 sets of 8-12 reps per leg. Or, perform 1-3 sets of 20-40 second intervals (doing as many reps as possible during those intervals).
Remember to perform the raises in a controlled manner, taking the leg through your full range of motion.
Working a few minutes of functional strength work, including this exercise, into your pre- or post-run routine can go a long way toward keeping you running injury free. Evidence suggests that many common running injuries, such as iliotibial (IT) band or knee problems, can be overcome by addressing a key weakness that numerous runners exhibit: weak hips. Why?
Consider this. As you run, you are effectively alternating between single leg stances—left leg, right leg, left leg, right leg—mile after mile, day after day, week after week, year after year. Without strong hip abductors, the hip on your non-planted side of the body drops and increases the forces on the IT band and knee of the stance leg. If you put in enough miles while running like this, overuse injuries will eventually result. This is why core strength for runners has little to do with “six-pack” abs and everything to do with strong hips.
Adam Hodges, PhD, is a USA Triathlon and USA Cycling certified coach, as well as an American College of Sports Medicine certified personal trainer. For a complete library of functional strength videos for runners and multisport athletes, visit his website at www.alpfitness.com.