Treadmills simulate running by using an electric motor to pull a moving belt across an immobile surface. This does not perfectly replicate running on level ground. In fact, running on a treadmill is easier than running outdoor for a variety of reasons.
As a result, the muscles involved in running receive less conditioning when performed on a treadmill. One reason for this is that the treadmill belt assists leg turnover, making it easier to run faster. So, most runners find that their pace on the treadmill doesn’t correlate to their road pace. The moving belt also reduces the workload on the buttock and hamstring muscles. As a result, these muscles get less conditioning in this exercise scenario than they would with outdoor running. Many serious runners also claim that much of the soft tissue conditioning or “hardening” that occurs with road running does not occur with treadmill running because the plate or base on the treadmill “gives” more than outdoor surfaces do upon foot strike.
And there is more to consider. The mechanics of treadmill running actually translate into running slightly downhill. As you may know, running downhill is harder on your knees and shins than running uphill.
So, for those that must rely on a treadmill for their running time/miles, try increasing the incline setting on your treadmill to just a 1 to 3% incline. Depending upon the treadmill manufacturer, this small increase will level out the surface below as you run, thus taking the strain off your knees and refocusing some of the workload to your buttock and hamstring muscles.
If your knees have been bothering you because of the treadmill, experiment with the 1 to 3% incline for a few days before you decide whether the changes are helping you or not. If your knees are still giving you trouble, it might be a good idea to take a break from the treadmill and hop on the elliptical trainer, which will give your knees a rest while allowing you to maintain your cardio routine. If that fails to help you, consider consulting a facility such as ours for an expert opinion and treatment of your condition.
When your knees start to feel better, hop back on the treadmill, but don’t forget to set your incline to 1 to 3%. Or better yet, do some outside running and enjoy some fresh air.