Running: Treadmill vs Outside

Well friends, we are back to Monday but this Monday feels a little different than most. I achieved a goal this weekend I set for myself at the beginning of the year…. I accomplished 12 miles on Saturday! They my best miles but I pushed myself and didn’t stop. I am planning on running a 16k in June so accomplishing 12 miles by March is a success! During this long 2 hour run, I started thinking about running outside vs running on a treadmill. For me, there is no way I would complete 12 miles on a treadmill. I find them boring and not real accurate compared to running outside. But, I prefer them over running in 20 degree weather!  So, I have put together some pros and cons for running on a treadmill compared to outdoor running:

The days are getting colder: shall we hit the treadmill or stick to running outdoors?

Pro: The difficulty level is the same

The question of difficulty level always arises when it comes to running indoors vs outside. People assume that running outside is harder than logging miles inside on a treadmill. However, research has proven that setting the treadmill to 1% incline accurately reflects the same energy costs of running outdoors. So, it’s just as effective as long as you add a little incline. For me, I like to see the hills ahead of me that I am about to conquer.

Pro: It’s easier on your joints

The smooth, cushioned belt is more forgiving than hard pavement or cement. Running on a treadmill can help reduce some of the impact on the joints and the body as a whole. This can be especially helpful when rehabbing or coming back from an injury. I have actually never actually faced an injury from running (yet), but I know you have to gracefully get back into it and be smart. If you are coming back from an injury, its always a good idea to alternate outdoor and indoor running to get the body back into motion.

Pro: You can simulate race environments

Many of the more advanced treadmills allow you to create your own unique course profile, which you can use to simulate the exact course you’re training for. Even if you’re not training for a race, you can switch up your workout by choosing a certain trail or terrain, depending on the options, to make you feel as though you’re half a world away. As far as weather, temperature, or terrain, the treadmill comes in handy which can mean everything if you live in a very cold or wet part of the country. If any of these do not bother you or you are a beast of an athlete, then outside running is better for training purposes. Since most races are set outside, training on the pavement is the best way to prepare for the race of your life.

Con: You could lose your agility

Speaking of the hills and terrain, although the treadmill might provide your joints with more cushion, you don’t get the added benefit of running on pavement. Even if the ground outside might feel flat to you, it never truly is. Therefore, your foot and leg muscles are constantly making small adjustments to adapt to the changing surfaces. These adjustments are great for coordination and balance. While treadmill running can help improve your overall fitness, it won’t mimic the real-life situations that are simulated through running outdoors.

Con: You don’t work as many muscles

Because there is a machine powering the belt, the muscle mechanics differ when you run on the treadmill. Outside, you typically rely on your hamstrings to finish the stride cycle and lift your legs behind you, almost kicking your butt. But on a treadmill, the propulsion of the belt does much of that work for you. You use your quads to push off, but your hamstrings aren’t firing as much as they would if you were running outdoors. If you’re only running on the treadmill, be sure that you’re also doing cross training to work the muscles on the back of your legs.

Con: It’s boring

There are no two ways about it: Running inside is boring. Even if you have the best playlist or you’re watching TV, it’s just too easy to look at that clock directly in front of you—and see that only 30 seconds have passed since the last time you checked it. (Tip: You can try covering the display with a towel to keep that clock out of sight). When running outside, the time naturally seems to move faster because you are literally covering more ground. Plus, you set a literal finish line for your run and see it getting closer and closer as you approach it. This provides you with a more natural sense of distance and will give you that extra push to finish strong when you feel like giving up.


  • I won’t run in the dark by myself so having the flexibility to run on a treadmill at any time is a bonus
  • my pace is faster when I run outside
  • I notice slight differences in my form when I run on the treadmill
  • I get bored on the treadmill even if I’m watching TV
  • I feel more “accomplished” after running outside
  • Outdoor running uses more muscle fibers and burns more calories for the same amount of work when compared to a treadmill.

Fortunately, I don’t have to choose one over the other. I will always prefer to run outside but having the option of a treadmill has it’s benefits and it’s better than not running at all. No matter what the weather forecast brings, I find running outside more refreshing and enjoyable compared to the treadmill.

Do you prefer running outside or running on the treadmill? What are some of your favorite training workouts or tips?

Brittany 🙂