Many athletes use treadmills for the majority of their running. I want to give those who are new to treadmill running, and those use the treadmill for workouts 5 plus days/week, some words of caution. First of all, it takes many hours of treadmill running to develop a smooth gait. This is why running research done on treadmills is normally closely scrutinized. Your first 50 to 100 hours of treadmill running can be biomechanically erratic. This is not true for normal ground running where the biomechanics are more predictable (but harder to video while doing research). As you run on a treadmill, each step passes through the "double float phase". That means both feet are off the ground. As you land one foot on the moving treadmill surface, the treadmill belt is either moving at your same speed, faster than you, or slower than you. It is the later two circumstances that can cause problems. If the belt is moving slower than you, the belt will try to decelerate your speed (put the brakes on), and your leg will feel the impact shock. If the belt is moving faster than you, the belt will try to accelerate your speed (move you along), and the foot and leg will be torqued or twisted as it is pulled abnormally on the belt. This is normally with an increase in foot and ankle over pronation. Even experienced treadmill users have this problem due to the daily variation of how tired their muscles are.
I know as I age, I am more unsteady on the treadmill, partly because I have my ipod going or straining to watch the TV monitor in front of me and I am too tall, and partly because I am getting older. I use the treadmill only sporatically on vacations, during the rainy season, or while I wait for my basketball game to begin. I, and all the erratic treadmill users like myself, need to be very careful to stay focused. The treadmill is inherently unstable, and when you add instability from another source or two, trouble is brewing.
Many feel the treadmill is a problem since it affects an athlete's natural stride. I can image that tall runners have more of a problem with this. The Golden Rule of Foot: Try to find your normal stride on a treadmill. If not, abandon it as a form of exercise.
So what are my recommendations:
- If you can run outside also, use the treadmill only 50% of your running (try to run outside every other workout if possible). Most runners modify this with treadmill during the work week, and outside on the weekends (days off).
- If you have any pain during or after running, try to analyze if it is worse running treadmill or outside. If obvious, try to emphasize the least painful environment.
- Understand that treadmill running can affect your biomechanics and you must stay focused on form, smoothness, and the onset of pain. The pain may more be related to the treadmill than the running itself.
- If you have any symptoms from running on the treadmill, even if minor, make sure that you keep the level at 0. Any elevation can increase the stress on many structures, including the achilles tendon.
- If you have no problems running on the treadmill, and have been doing it for years, still consider cross training by doing some running outside (slightly better impact for bone development).
- When you are tired, after a long day or a late night before, treadmill running will definitely produce the most biomechanical problems for you. Consider cross training with the ellyptical or stationary bike.