Now that spring is here (if you live in Maine, pretend all that snow has melted) who doesn’t want to be outside? I’ve noticed lots of people out running lately. But even when the weather is perfect for it, running outside is not always an option for some people. So … does it really matter if you run (or walk) outside or inside on a treadmill?

Dr. Christopher Scott, exercise expert

Source: University of Southern Maine

I put the question to an exercise expert — Dr. Christopher Scott, who directs the Human Performance Laboratory at the University of Southern Maine.

His answer:

“Clearly running surfaces can effect the outcome. Surfaces like sand can greatly increase overall costs. My impression is that when surfaces are considered equivalent there is not much difference between running on a treadmill or running outside. Obviously wind resistance can affect energy cost outcomes too, but I recall reading once that you can keep air resistance relatively equivalent by raising the treadmill grade 1-2%.”

In other words, if you’re outside surface is similar to your treadmill, you’re probably getting a similar workout.

By the way, “cost or energy cost” is the number of kilocalories or kcals you burn per minute running at a given speed or doing any kind of activity. For instance, if you run in sand, you’ll burn more (increase cost) than if you run on a paved surface or a treadmill.

I like to walk. I use the treadmill in bad weather or during winter, but much prefer being outside in warmer weather. What about you?
Trail at sunset

The view from one of my favorite walking trails