How does running on a treadmill compare to running outside? Is one easier than the other?

It’s a common question and despite conflicting opinions, scientific research has shown that running on the treadmill is roughly the same as running outside if you make a few simple adjustments.

 In fact, there are some types of workouts you can do better on a treadmill than you can outside. However, running on a treadmill does have its disadvantages, and for some runners, 1km on the “hamster wheel” can end up feeling like 10km outdoors.

So what’s the difference?

When running on a treadmill, the belt is moving under you and there is no wind resistance for your body to counter, so it should be easier to run. In fact, you could jump up and down on a treadmill and it would record that you’re running at whatever speed the belt is moving. On the other hand, outside running requires your legs having to propel your motion forward, while pushing through the resulting wind resistance (however minor it may be).


Luckily, scientific research has proven that setting the treadmill to a 1% gradient/incline accurately reflects the energy costs and simulates outdoor running. So, by setting the treadmill to a 1% incline, you can offset the lack of wind resistance and the belt moving under you to make treadmill running the same effort as running outdoors. Supporting research has shown that VO2 max is the same when running on a treadmill compared to outside, clearly demonstrating that running on a treadmill is as effective as running outside.


However, there are some differences to be mindful of:

As the treadmill belt is powered by a machine, the mechanics of your running stride differ when you run outside. When running on the treadmill, you use your quads to push off. But, unlike outdoor running, where you would typically rely on your hamstrings to finish the stride cycle and lift your leg behind you, the propulsion of the belt does much of that work for you. This means your hamstrings aren’t firing as much and don’t get worked running inside as they would outside. The extra effort demanded of your quads is also a factor to keep in mind.


The lack of terrain changes on the treadmill makes it really consistent and even, but outside things are constantly changing. Each change takes energy and thought. If you are mostly running indoors, your body will get used to a nearly even and constant stride. Should you decide to then run outside, your risk of an injury from even a minor misstep would be higher because the small muscles, tendons and ligaments of your ankle haven’t been forced to get used to a variety of landings. To safeguard your ankles, work on balance and mobility drills such as balancing on one leg on a Bosu ball or pillow.


When should you consider the treadmill rather than the fresh outdoors?

During bad weather and footing – although this is the most obvious benefit of treadmill running, it’s important to mention as the elements effect every runner differently. Getting in a good workout on the treadmill is better than suffering through a bad run or getting hurt, so don’t be afraid to hit the treadmill on the days you need to.


Safety – either when it is too dark out to safely navigate your route or when you don’t feel safe running your route alone (esp in the dark). When in doubt, rather take your training indoors than risk it outside.


Simulating race courses – one of the unique benefits of a treadmill is the ability to simulate your goal race course. Many of the more advanced treadmills allow you create your own unique course profile, which you can use to simulate the exact course you’re training for.

Just program the machine, or if you don’t have that option, manually adjust the incline levels based on the course map, and you can train on the course any day of the week.


Injury prevention – the belt of the treadmill is more forgiving than the hard pavement; running on a treadmill reduces impact and is easier on the body. This can be especially important for those coming back from an injury.


Fluid & Carbohydrate intake – it’s critical that you practice taking in fluids and carbs on your runs (esp if you are training for a marathon / half marathon), to teach yourself how to eat and drink without stopping. This can be a logistical nightmare if you don’t plan on carrying your water or gels with you. But, running a tempo run or long run on the treadmill will allow you to practice eating and drinking without slowing down. While the treadmill won’t make the actual act of eating or drinking any easier, it can make it logistically possible.


Family – leaving the kids unattended to go out for a run isn’t exactly a glowing parent strategy. So if you have a treadmill at home, great, then you won’t need to leave, if not, take the kiddies along to the gym, most have a section where the kiddos can play and have fun whilst you get your run on.


When does outdoor running trump the treadmill?

Pacing yourself – you don’t learn how to pace on a treadmill. On a treadmill, it’s easy to “set it and forget it” and just lock into a target pace. Unfortunately, this method doesn’t teach you how to properly find and maintain pace on your own. As a consequence, you stunt the development of your internal effort and pacing instincts, and you might find it difficult to get into a rhythm of your own next time you hit the road.


Boredom prevention – without scenery passing you by and something to take your mind off the blinking lights on the treadmill, it’s too easy to look at the clock every 30 seconds and get discouraged that more time hasn’t passed since your last glance. Likewise, when you’re running a tough workout outside, you can “feel” the finish line getting closer and you have a more natural sense of the distance remaining. On a treadmill, your mind can’t visualize the finish line, so it becomes harder to concentrate when the pace gets hard and you need to push yourself.


In our opinion, you should approach running on a treadmill like you should with everything in life – in moderation.


The bottom line:

The treadmill can be a great training tool and essential for those of us who live in harsh weather environments (both hot and cold) or don’t feel safe running outdoors. However, don’t neglect the specific skills you need to develop by running outside on occasion. If you’re doing much of your running indoors, make sure to supplement with extra hamstring-strengthening exercises, as well as ankle stability exercises.


For exercise prescription contact one of our qualified Biokineticists to assist you on 072 328 3663 /


Coach Jeff. Treadmill Vs Running Outside: Which is Best for Runners?. Runners Connect. Available online at Retrieved 03-03-2018.


Chock, C. Indoor vs Outdoor Running: 3 things to know about treadmill running. Available online at Retrieved 03-03-2018.

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