Welcome to NoLimitsTiming - The best resource for running information on the web.

5 Real Reasons (With Solutions) You Run Slower on A Treadmill

Hello! Welcome to our site! As an Amazon affiliate, I may earn commission from some of the links on my site. This is at no cost to you - you pay the same price. Read more on our disclosures page.

why do i run slower on a treadmill graphic

Sometimes, when running on a treadmill, time can slow down. That last 5 minutes seems to take an eternity and the workout is seemingly endless. The perception can be that the run is slower or is taking longer than it should. It’s common to ask yourself, “Why do I run slower on a treadmill?”

Many people run slower on a treadmill because they are bored, they don’t do as well with a constant pace, they are hotter and more uncomfortable indoors, the treadmill doesn’t fit their gate and they have less room to move around. This can give you the perception you are running slower.

Running on a treadmill can be deceiving. While it may seem like you’re running at the same speed, you’re going slower because the belt is moving you. You may also actually be running the same speed and it just seems like you’re going slower. Honestly, it’s hard to tell sometimes.

This means that if you’re looking to improve your speed or endurance, it’s best to run outdoors where you’re fighting against gravity. Treadmills are great, and have many benefits, but there are also a handful of disadvantages to running on a treadmill. We’ll talk about some related to speed below.

Is It Normal to Run Slower on A Treadmill?

It is normal to be a bit slower on a treadmill. At least, to feel a bit slower on a treadmill. A lot of anecdotal evidence is that while a person can run an 8:30 mile outside, they struggle to hit a 9:00 mile on a treadmill. Even treadmill running speeds for beginners can be slower than road speeds. It affects everyone.

Many people claim they run slower on a treadmill for a few reasons.

  • They are bored
  • The set pace slows them down
  • The lack of airflow causes people to sweat more
  • The treadmill doesn’t fit their gait
  • Less freedom to move

1/ You Are Bored

There is a large mental aspect to running.

You hear this over and over again. Many runners say that running is 90% mental and 10% physical. If you are bored on a run, it will be harder to push through and maintain a good pace.

“Running is 90 percent mental and 10 percent physical.”

Everyone. Literally, everyone.

While cliche, it isn’t untrue. If you’re bored you won’t perform at anything. Find a way to spice it up. You might find that you need to change up your scenery when running on a treadmill.

This can be as simple as watching television or turning on some music. Some people even recommend reading while running on a treadmill.

Solution: The key is to find something that will take your mind off the fact that you are running on a treadmill.

2/ The Set Pace Slows You Down

Many people run based on feel. They go out for a run and start at a comfortable pace. They then gradually increase their speed as they warm up and settle into the run.

On a treadmill, you are confined to a set pace. This can make it difficult to find a rhythm and slow you down. Many runners naturally speed up at times and slow down at times. Even though the difference is slight, over time it can add up to be significant with an overall average that is faster than their steady state. Tempo runs, for example, can be annoying on a treadmill at times.

If you are used to running outdoors, it is important to keep this in mind when starting on a treadmill. Do not try to match your outdoor pace right away. Start slow and gradually increase your speed as you get used to the treadmill.

Solution: Set your pace slightly higher than you may want to start out and try to hang in there. Outdoors, you can “make up ground” if you have extra energy. On the treadmill, it’s more difficult.

3/ You Get Hotter and Sweat More

While this may not be true for everyone, this can be annoying and is a reason for some to slow their pace on treadmills.

At the very least, the lack of airflow can cause people to heat up and sweat more than they would if they were running outside. If you are someone who runs hot, this can be a difficult adjustment.

You might find that you need to lower the intensity of your run or take more breaks when running on a treadmill. Again, it is important to listen to your body and do what feels comfortable for you.

Solution: Buy a big fan or other option to keep yourself cool. If possible, crank the AC or spray yourself with some water. Take off clothes. Whatever it takes.

4/ The Treadmill Doesn’t Fit Your Gait

Treadmill exercise

This is particularly true for larger individuals. Runners with a long stride may struggle to stay within the confines of the treadmill. Nobody wants to fall off the back, right? But, staying too far forward may inhibit a runner from getting a fully developed stride. Running on a treadmill works a lot of muscles at the same time and any change in gait can lead to muscle imbalances over time as well.

This will result in shorter steps and, ultimately, a slower pace. If your gait is affected in a way that causes you to lean backwards and extend your leg, it could have a negative impact on your knees as well.

Solution: Try to focus on staying in the middle and using a full stride if possible.

5/ Less Freedom to Move

This is another issue for those with a long stride or those that don’t run perfectly straight. On a treadmill, you are confined laterally as much as longitudinally. This can make it difficult to get into a groove and find your rhythm if you tend to swing side-to-side when running.

On the other hand, outdoors you have the freedom to move around as much as you want. You can adjust your stride and find a pace that feels comfortable for you.

Solution: Optimal running form isn’t synonymous with swaying from side to side anyway. Fix it. The straighter you run, the less distance you run. Use this as an opportunity to straighten out your runs outdoors and inside.

Are Treadmill Speeds Accurate?

Today’s treadmills are packed with some pretty impressive technology. They can track your mileage, heart rate, and even elevation.

But, are they accurate?

Generally speaking, yes.

Treadmills track speed by understanding how many revolutions of the belt happen in a given period. Since the belt is a known length, they can understand how fast the belt is moving. We then transfer that speed to the runner and assume the runner is moving that speed as well.

Treadmills tend to overestimate your speed, and therefore, your mileage. This is because the belt is moving and you are not covering as much ground as the treadmill says you are.

Similarly, this study found that treadmills both overestimate and underestimate speed and distance based on a runner’s biomechanics. Go figure.

Luckily, there is a simple way to check your speed if you think it may be off. Simply take a piece of tape and tape it to the belt. Run the treadmill at a certain speed, say 6mph, and time it for a minute to see how many revolutions the belt did.

Measure the belt. Now, you can use math to validate (or disprove!) your treadmills speed output.

Is It Harder to Run Fast on A Treadmill?

Close up of treadmill control panel

Surprisingly, no. It’s easier. Now, when I talk about running faster, I mean in an all-out sprint situation. For longer distances, like mile times and 5-mile runs, your pace is going to be slower on a treadmill for the aforementioned reasons.

There are a few reasons it’s easier to run fast on a treadmill in the short-term.

Wind Resistance

Wind. Generally, unless you’re using a high-powered fan to get rid of the overheating issue above, there is little to no wind in your gym, basement, or wherever else you have your treadmill.

Wind blowing in your face will slow you down and tire you out faster, therefore making it difficult to keep a steady pace like you can on a treadmill.


Another factor you deal with outside and not on a treadmill is an incline. Uphill running is tough. It takes more energy and effort to run at the same pace on an incline as it does on a flat surface.

On a treadmill, you can adjust the incline to make it more difficult, but you don’t have to deal with any unexpected hills. You can also change the incline throughout your run if you want to mix things up.

But, for pure speed, you’re completely flat and that helps.

Pace Changes

Lastly, the ability to make split-second changes in pace is more difficult outside. If you want to speed up or slow down, it takes more time and effort to do so when you are running outdoors.

You may not think this would be a big deal, but being able to make small adjustments in pace can help overall speed assuming other factors are accounted for.

Treadmills Can Still Be Beneficial

Even though there are some drawbacks to running on a treadmill, they can still be beneficial. If you live in an area with inclement weather, a treadmill can be a great way to get your miles in without having to brave the elements.

When asking yourself, “Why do I run slower on a treadmill?” – understand that it’s a different game than running outside.

This is why most people use treadmills as a training tool to help them prepare for outdoor races. Understanding that a treadmill is simply a tool, and as such needs to be calibrated, helps.

Share this post

About the author

Jasper loves to write about fitness, running, and anything else that gets him moving outdoors. He's an avid hiker, backpacker, and climber who loves to stay fit so he can make sure he's healthy enough to enjoy his favorite hobbies. He also spends time writing about his true passions in life.