Treadmill vs. Outside Running

The debate over whether running outside or on treadmills is "better" is not a new one. Some people will tell you that running outdoors improve stability by forcing you to navigate ever-changing terrain. Others will insist that a treadmill forces you to sustain speed and performance levels that might other lag outdoors.

Ultimately, there is no right or wrong answer to the debate. Both methodologies have their pros and cons based on your individual training needs and goals.

Treadmills are one of the most popular pieces of cardiovascular equipment both at home and in gyms. According to the U.S. Consumer Product Safety Commission (CPSC), over 50 million Americans use a treadmill each year, an increase of no less than 40 percent from 2000.

Among the advantages of treadmill running:

• There are no weather and temperature constraints.
• You can stop anytime you want.
• The smooth, cushioned surface is easier on the joints.
• You can have easier access to restrooms when needed.
• You can do it alone and at any hour.

While treadmills are considered the safer option by most users, the CPSC reports that there are over 24,000 treadmill-related injuries in the U.S. each year. These include sprains, falls, head injuries, and cardiovascular events in people who either ran too fast or pushed too hard.

While elite athletes will use a treadmill as part of their training routine, they will do the majority of their running outdoors on tracks, trails, or pavement. The advantages of outside running are simple:

• You don't need a gym membership.
• You can continue training even when travelling.
• It provides sport-specific training for road races.
• It allows you to enjoy nature and breathe fresh air.
• It can be motivating as it requires you to complete a distance goal rather than just stepping off a machine.

According to research from the University of Applied Sciences in the Netherlands, anywhere from 7.2 percent to 50 percent of runners will experience some sort of injury. Knee injuries are by far the most common, followed by lower leg, foot, and ankle injuries, respectively.

Athletes can get the same workout whether running on a treadmill or outside as long as they maintain the same effort level. But "effort," in and of itself, is a highly variable measure.

Clinically speaking, effort is based not only on your heart rate but a phenomenon known as perceived exertion. Perceived exertion refers specifically to how "hard" you consider an activity to be, irrespective of how your body responds to that activity.

For example, the perceived exertion of running indoors will generally be less than running outdoors on a rainy day even if you burn more calories or have a faster heart rate. Even on a sunny day, the very act of running up a hill may be perceived to be "harder" than running at the same incline and distance on a treadmill.

Perceived exertion matters because we tend to give up sooner if something is perceived to be difficult. This psychological component can influence how much we get out of one exercise compared to the next.

However, if assessing the real, rather than perceived, benefits of running, outdoor running will usually come out on top. Even if you run at the same pace on a treadmill, you will generally expend more energy running outdoors. This is not only due to variations in terrain, weather, and wind conditions; the treadmill ultimately does a lot of the work for you by propelling you forward.

To compensate for the difference, race runners will often increase the incline of the treadmill by anywhere from one to five percent during training.

Still, it doesn't mean that a treadmill will even come close to providing you the skills needed to effectively run a race.

If your sole intention is to meet and maintain your cardiovascular fitness goals, a treadmill may be all that you really need. By pairing the exercise with an accurate pulse monitor, you can push yourself appropriately while keeping well within your maximum heart rate (MHR).

On the other hand, if training for a race event, you will clearly benefit more from running outside. While you can incorporate treadmill running to improve your cardio health, limit it to no more than 40 percent of your overall training.

By running outdoors, your muscles and joints will be more conditioned to the varied terrain you'll encounter in a race. You'll be better able to adapt to changes in weather and know when to exert extra effort when faced with elevations or known obstacles.

Another important point: most treadmills do not have a downward incline feature which you need to strengthen the anterior tibialis muscles at the front of your legs. Similarly, there are no turns on a treadmill machine, limiting your ability to improve your lateral agility.