Side Plank – The Forgotten Plank Exercise

By Rick Morris

The plank exercise is one the most effective and widely used core strength exercises for distance runners. The plank does an excellent job of strengthening your abdominal muscles as well as muscles in your upper legs, hip, and back. The standard plank workout,  in which your straight body is in a prone position with support provided by your elbows and toes, is a very common one that is performed on tracks and in gyms worldwide. But there is a forgotten cousin of the standard plank that is a very beneficial plank exercise for distance runners – the side plank.

The Side Plank

The side plank is performed in similar fashion as the standard plank, except you are on your side. You begin this plank workout by lying on your left side with your weight supported on your left forearm and the side of your left foot. Your right leg and foot should be stacked on top of your left. Your body should be completely straight and supported off the ground. Only your left forearm and the left side of your foot should be touching the ground.

Always keep your core abdominal muscles activated to stabilize your body.

For the next step you raise your right leg laterally away from your body and hold that position for 20 to 30 seconds. Relax and repeat on the same side for your desired number of repetitions. Now switch sides and repeat.

Muscles Worked

All plank exercises work multiple muscles in your body. That is one of the reasons they are so effective. The primary muscles of concern to distance runners,  strengthened by the side plank are:

  • External oblique abdominal muscles – lateral lumbar flexion and rotation
  • Internal oblique abdominal muscles – lateral lumbar flexion and rotation
  • Erector spinae muscles – lateral spinal flexion
  • Quadratus lumborum muscle – lateral hip flexion and hip stabilization
  • Tensor fasciae latae muscle – abduction of the hip
  • Gluteus medius muscle – abduction of the hip
  • Gluteus maximus muscle – abduction of the hip

Functional Movements Strengthened

It’s all good to be aware of the muscles you are working, but even more important is to know what functional movements you are strengthening and how it helps you as a runner.

The most important distance running movement the side plank improves is your hip abduction strength. You abduct your hip when you move it laterally away from your body. That motion may not seem important to a distance runner. After all, you rarely run from side to side. But hip abduction comes strongly into play in a very important phase of your running mechanics – your hip stabilization. The primary role of hip abductor muscles are to move your leg laterally at the hip, but that same muscle action also prevents your opposite hip from collapsing when your leg and foot are anchored during foot strike. For example, when your weight is supported by your left leg and foot, the hip abductor muscles acting your left hip, prevent the right side of your hip from collapsing downward.  If your hip collapses or becomes unstable your entire running stride will collapse with it. The side plank works those hip abductor muscles strongly in stabilizing your hip and you reap the benefits with superior running economy, endurance and power.

While hip abduction is the most important benefit of the side plank to a distance runner, the side plank also builds strength in your lateral abdominal muscles and the muscles that stabilize your spine, all of which contribute to superior running economy, injury resistance and endurance. All of those muscles combined will improve your running economy and endurance.