As a certified running coach, one of the most common questions I get is: “Is it better to run on the treadmill or outside?”
When it comes to running on the treadmill vs outside, the truth is—there’s no one-size-fits-all answer. Both offer unique benefits and drawbacks, and the right choice depends on your goals, the weather, your training phase, and even your personal preferences.
For the record, any type of running—indoors or outdoors—improves cardiovascular health and fitness, increases daily calorie burn, strengthens muscles, increases bone density, and improves physical and mental well-being.
In this guide, I’ll break down the pros and cons of both treadmill and outdoor running, explain how they affect your body and mind differently, and help you decide which option best supports your training—whether you’re prepping for race day or just trying to stay consistent.
What Are the Benefits of Running On A Treadmill?
#1: Stay Consistent with a Controlled Environment
Treadmills offer a controlled environment with little to no wind resistance, temperature fluctuations, or uneven footing.
This makes running on the treadmill safer and more comfortable in inclement weather, such as when it is freezing cold or snowing, windy and rainy, or hot and humid outside.
The climate-controlled environment also allows you to stick with your running workouts and hit your target paces and heart rate zones without having bad weather conditions impact your performance.
Treadmill runners don’t have to worry about safety if they run alone or in the dark.
The best treadmills have excellent cushioning, which can decrease the risk of injury relative to road running on concrete or hard asphalt.
#2: Prioritize Convenience Without Sacrificing Workouts
Running on the treadmill can be a lifesaver when life gets busy. If you have a home treadmill and need to squeeze in runs while juggling childcare or a packed schedule, it’s an easy, accessible option that removes the barrier of getting out the door.
#3: Train With Specificity
A quality treadmill allows for targeted training through features like incline and decline. You can simulate hill workouts, control your pace for interval sessions, or build climbing strength for trail and ultramarathon prep.
#4: Built-In Entertainment and Motivation
One of the big perks of treadmill running is distraction. Watching your favorite show, listening to a podcast, or using interactive apps like iFit or Peloton can boost motivation and help the miles fly by. For some runners, that’s the difference between skipping a workout and getting it done.
#5: Social Running at Your Own Pace
If you are running on the treadmill at the gym with a running buddy, you can each be doing treadmill running side by side and talking yet have very different running paces or treadmill workout scheduled, which can’t happen with outdoor running workouts.
This is a great option for partners of different fitness levels or following different training plans.
What Are the Cons of Treadmill Running?
#1: Repetitive and Sometimes Just Plain Boring
Let’s be honest: treadmill running can feel monotonous, especially for long workouts. Even with your favorite playlist or podcast, the lack of changing scenery can make time drag.
Many runners find it harder to stay mentally engaged on the treadmill compared to the natural stimulation of running outdoors.
#2: Can’t Replicate Running Outdoors
The treadmill belt is a moving belt, so the muscle activation is somewhat different and may not adequately replicate the biomechanics of outdoor running.
Because the motor pulls you along it is important to set the treadmill incline to 1%1Jones, A. M., & Doust, J. H. (1996). A 1% treadmill grade most accurately reflects the energetic cost of outdoor running. Journal of Sports Sciences, 14(4), 321–327. https://doi.org/10.1080/02640419608727717 to replicate the metabolic and muscular requirements for road running outdoors.
Training exclusively on the treadmill instead of running outside may not prepare you for race day due to the terrain on the roads, the different muscle activation from having to self-propel as you run, and the challenges of wind resistance running outdoors.
Unless you are running on one of the best home or commercial treadmills, you likely won’t be able to simulate declines or downhill running which is key for some races.
#3: Potential for Overuse Injuries
The repetitive nature of the smooth surface of the treadmill belt can increase the risk of injury from overuse unless you vary the speed and grade of the treadmill.
#4: Your Shoes Might Wear Out Faster
The constant friction and heat from the treadmill belt can break down your running shoes more quickly than road or trail running. If you’re logging lots of indoor miles, keep a closer eye on your shoes’ wear and tear and rotate pairs regularly.
#5: It Can Get Pricey
Treadmill access isn’t free. If you don’t own one, you’ll need a gym membership—and if you do plan to invest in one, a good treadmill comes with a steep price tag.
What Are the Benefits of Outdoor Running?
#1: Allows You To Prepare Better For Race Day
Running outdoors helps you train in the same conditions you’ll race in—whether that means road, trail, wind, or hills. It prepares your body and mind for the real-world variables that a treadmill can’t replicate.
#2: Engages More Muscle Groups
Varied terrain, elevation changes, and the need to self-propel work a wider range of muscles and tendons. This not only strengthens stabilizers but can also reduce the risk of overuse injuries common with repetitive treadmill workouts.
#3: Mental and Physical Health Boosts
Fresh air, sunlight, and natural scenery can elevate mood, reduce stress, and contribute to overall well-being.
In fact, research shows that exercising in outdoor environments can have greater benefits for mental health than indoor workouts.2, T. C., K, B., K, S., R, W., J, B., & Mh, D. (2011, March 1). Does Participating in Physical Activity in Outdoor Natural Environments Have a Greater Effect on Physical and Mental Wellbeing Than Physical Activity Indoors? A Systematic Review. Environmental Science & Technology. https://pubmed.ncbi.nlm.nih.gov/21291246/
4. It’s Free
Running outside requires no membership, subscription, or expensive equipment. Lace up your shoes and head out the door—saving money while still getting a high-quality workout.
What Are the Cons of Running Outdoors?
#1: Unpredictable Weather Conditions
Outdoor runs expose you to the elements. Rain, snow, heat, wind, and icy paths can make training uncomfortable or even unsafe, especially during long runs or speed workouts.
You may have to adjust training due to less-than-ideal conditions.
#2: Increased Risk of Missteps
Uneven pavement, trails, or poorly lit areas increase the risk of tripping, rolling an ankle, or falling—especially when you’re tired or running on unfamiliar routes.
#3: Sloped Roads Can Lead to Imbalances
Cambered roads or sidewalks with a tilt can cause uneven loading on your legs, which may lead to hip, knee, or ankle discomfort over time.
#4: More Impact on Your Joints
Hard surfaces like concrete and asphalt provide less shock absorption than a treadmill deck, which can increase stress on your knees, ankles, and hips—especially during high-mileage weeks.3NILSSON, J., & THORSTENSSON, A. (1989). Ground reaction forces at different speeds of human walking and running. Acta Physiologica Scandinavica, 136(2), 217–227. https://doi.org/10.1111/j.1748-1716.1989.tb08655.x
#5: Limited Access to Hills
If you live in a flat area, it can be tough to get in meaningful hill work. Treadmills often allow for more controlled elevation training with consistent incline options.
#6: Less Flexibility for Multitasking
Unlike treadmill runs at home or in the gym, it’s harder to watch a show, monitor kids, or chat with a buddy going a different pace when you’re out on the road or trail.
Both treadmill running and outdoor running come with their own set of benefits and drawbacks. The treadmill offers a controlled environment, convenience, and precise workout execution—while outdoor running provides real-world terrain, mental stimulation, and race-specific preparation.
Yes, the treadmill may earn its nickname “the dreadmill” for a reason—but that doesn’t mean it doesn’t have a place in your training. Whether you’re escaping bad weather, squeezing in a late-night run, or doing targeted hill repeats, the treadmill can be a powerful tool when used intentionally.
Ultimately, the best option depends on your goals, preferences, and circumstances. Now that you know the pros and cons of each, you can make an informed decision that supports your running—and keeps you moving forward, wherever you choose to run.
For some treadmill workouts to get you started, check out this next guide:
My biggest problem with treadmills is pacing.
When I go out on the road (on my own) I always end up going out too fast and burning up quicker than I ought to, whereas on a treadmill you set the pace and it keep at that pace) – It is something I’m going to have to master as there are very few runners where I am and find it really difficult to find a running partner as I think this would really help?
Paul,
What about running with a GPS watch so you can track your pace?
Thanks,
Thomas