For me, I split time running outdoors and running on the treadmill. I have had many ask me if there is a difference, so I thought I would put together an article on both my experiences and the research out there.
I typically use the treadmill on either rainy, cold, or hot days. The only other times I will move a run indoors to the treadmill is when I did not get my outdoors run in early in the day, and it is too dark or unsafe to run outdoors. However, when it is Spring in the South like it is now, all I want to do in run outdoors! Spring is time to get out from the Winter covers and move the running back outdoors! The treadmill will help you maintain cardio during the winter, but outdoors is where you polish off that running form!
If all you can do is treadmill work, it is better than nothing, and will help or get you conditioned for running. If you are just starting out running, get on that treadmill. The treadmill will help your modify and control your effort, and it is also convenient. Although the treadmill is an effective way to get in your runs, it is important to know it is different than running outdoors. When you’re on the treadmill, you are keeping up with the tread and not propelling yourself forward. This is not a bad thing, it’s just different than outdoors. You you try and make sure at least one of your runs is outside every 1-2 weeks of training. This will allow for adaptations in your form.
The treadmill will give you both calorie burning and fitness benefits similar to outdoors running. However, there are differences. Lack of wind resistance, the flat surface of the treadmill, and stride vary greatly between the two. Running on a treadmill will seem easier, because you have the belt pulling you along, and there is no wind resistance to push through. The best way to simulate outdoors on a treadmill would be to set your incline at 1% for a little resistance. The slight incline will make your treadmill workout more equal to running outside on level ground. “When running on the treadmill you are running in place. You are not moving through the air. When you run outside the air creates resistance. Studies have estimated that outside air resistance creates an increase in your workload of between 2% and 10%, depending upon your running speed. The faster you run, the more of an effect the air resistance has on you.”
When running outdoors, the ground below you is ever changing. You might move from concrete to gravel or grass to asphalt. The smooth and even surface of the treadmill cannot be made rough and uneven.
“Proprioception is an important skill when running on the treadmill. Proprioception is basically intuitively feeling and knowing the position and motion of your body, feet, legs, arms, etc. at all times. It is being aware of all of the different actions of your running stride. This is something that, to a limited extent, you do naturally. But to maximize your level of awareness, practice consciously being aware of your position on the belt, the amount of forward lean, the position of your hips, the angle of your feet and all stages of your running stride.” When running outside, you encounter all types of uneven and unstable running surfaces. A changing surface will force your neuromuscular system to become more proprioceptive because it must make split second adjustments in order to keep your body stable and moving in the right direction. The flat and even surface of the treadmill removes this valuable training opportunity. So, if you do most or all of your workouts on the treadmill, you should practice proprioception at all times.” http://www.runningplanet.com/training/treadmill-versus-outside-running.html
Your running form should not change when you are training on the treadmill. Unfortunately, the moving belt of the treadmill can create havoc with your running mechanics. The moving belt can cause some runners to lean too far forward at the waist in an attempt to “keep up” with the belt. All runners should concentrate on proper form when they run, whether they train on a treadmill or the road. This is especially important for new treadmill users. It is much better to perfect your form right away, rather than acquire bad running form habits that may be hard to break. Good running form is the same no matter where you train.
The most common form problem associated with treadmill running is the tendency of the moving belt to “grab” your feet and pull them back under your body. This can result in a stumbling, shuffling stride that places excessive stress on your knees, hips and back. To avoid this, concentrate on quickly lifting your feet off the belt. You should have a quick, compact running stride, which is also the best outside running stride. Count the number of strides you are taking in 1 minute. If you are running correctly you should be taking approximately 85 – 95 full strides per minute. If you are taking less than that you are spending too much time on your feet.
Mentally, you may have a tougher time dealing with the monotony of the treadmill. It’s easier to distract yourself when running outside.
The bottom line: If you’re training for a specific outdoor race, try to train outside as much as possible to get prepared for race conditions.