Treadmill vs. Running Outside

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Treadmills give us the perfect indoor environment to take our cardio to the max. There’s a reason that they’ve been the fan favorite cardio machine for decades, and it comes down to control.

It’s a controlled environment where you can measure calories, distance, and success with relative reliability. If you have fitness goals, you can plan them out day by day on a treadmill.

But hold on: we’re forgetting something. Isn’t running outside the same thing, or in some cases even better?

It depends on a lot of factors, so first, let’s go through the pros and cons of using a treadmill, and running outside before we dip down into a deep comparison.


Benefits of Running on Treadmill

These beautiful machines spin a tread beneath our feet as fast as we want them to, and we’re off to the races.

Treadmills have plenty of benefits, but there’s a few aspects of them that aren’t so great (that most of us never think of). Let’s talk about what makes them tick, and what you need to look out for.


  • Unaffected by Weather: Is the electricity on? Then you’re good to go! You don’t have to worry about how hot it is, whether it’s raining or not, or worry about seasonal changes.
  • Easier on Your Joints: Treadmills will absorb shock and not send it through your feet and legs (mostly). Stabilizers on treadmills are really useful and powerful, but they won’t absorb all of it. Especially on inclines.
  • Extremely Measurable Results: You can use meters to track how fast you lose calories. While this can be done by running outside and you can use an Apple Watch to measure results, you can control the conditions and ensure continuous results on a treadmill.


  • No Downhill Runs: Running downhill engages your muscles differently than running uphill. Even if you have an amazing treadmill with a serious incline to it, you can’t run downhill. Those treadmills just don’t exist, so you can miss out on this level of diversity in your running routine.
  • Easy to Lose Interest: Let’s face it: it’s much more exciting to run outside, pick a new path, or see how the world is changing around you. Even if you do take the same path every single day, it’s more exciting than running on a spinning tread.

Running Outside

Benefits of running outside

Running outside is almost always better than running indoors, but it depends on variables that you can otherwise account for on a treadmill. Running outside isn’t a controlled environment, so the outcome isn’t always what you’d expect.

There’s also some health concerns we need to get into, so buckle up and let’s take a look at what running outside does for you, and what it does against you.


  • Excellent Muscle Engagement: If you’re not engaging your muscles, you aren’t growing them. Muscle growth and the “Afterburn Effect” are crucial for resistance training, and running outside often provides more resistance than running inside on a treadmill.
  • Burns More Calories: While you can control and measure your treadmill environment, running outside engages more of your body so you end up burning more calories through dynamic movements and motion. Simply put, you can lose weight faster if you run outside, but as for maintaining your weight once you’re at your goal, either method is fine.
  • Cheap to Get Started: You just need some shoes and inexpensive workout clothing. Treadmills are hundreds (or thousands if you want a good one).


  • Joint Damage: You accrue far more joint damage by running outside than you do inside. Treadmills are made with stabilizers to help absorb shock, but the hard earth isn’t going to be so kind to your joints.
  • Weather Dictates Your Run (and Safety): If it’s pouring cats and dogs, you can’t (safely) go on a run. Even if you do, you can easily feel how dangerous the slick ground is, and you won’t be able to hit your maximum potential. Treadmills are dictated by your electric bill, not the weather.
  • Risk of Skin Cancer: High UV days are only becoming more common as time goes on. You’re exposing yourself to major levels of UV (depending on what area you live in) and increasing your risk of skin cancer. A risk you don’t have to face indoors on a treadmill.



Now that we know the pros and cons of both, it’s time to put them against each other and see who comes out on top.

We have five main categories to explore that should cover 90% of all the details you need to know about which running method is best for you.

Calories Burned

Running outside wins here, but not for lack of effort by the treadmill. Even if you put the treadmill on high and you’re running like a beast, the tread is still moving.

The ground below you is moving, and taking away some of the muscle engagement that you get by propelling yourself forward. It’s just not quite the same.

You will burn more calories by running outside because of variables such as incline, terrain, and of course the fact that you’re moving yourself completely unassisted by a machine.


HIIT workout on treadmill

This one is interesting. Running outside is actually terrible for HIIT even though most people wouldn’t assume that.

The very nature of HIIT is to be in a controlled, steady, and stable environment. You have to measure intervals and take breaks. You can’t just decide to stop running when the clock hits two minutes if you’re in the middle of a busy intersection, or there’s nowhere to rest.

With HIIT, you have to control every aspect of the exercise. HIIT is usually done in air conditioned or at least temperature controlled environments, helping you regulate body temperature and not go overboard.

Treadmills can still give you great intensity, and when you have to stop, you can just turn it off and take your one minute bit of rest without worrying about the variables of being outside. Plus, no sun exposure while you’re just standing still. It’s a win-win.


Outdoor cardio exercise

Running outside technically wins this category, but it depends. You can still get amazing intensity while being on a treadmill indoors, but that doesn’t equate to the same amount of cardio effort.

Cardio is about getting your heart rate going more than anything else. Running outside means you might have traffic lights to wait for, cars to keep an eye on, and the entire environment is more distracting.

It depends on where you live, of course, but it’s going to greatly dictate which method of cardiovascular exercise is better for you.

If you can handle the incline and live in a hilly area without much traffic, you should run outside instead of using a treadmill. Running outside comes with more benefits and you can still get to the same BPM as you will on a treadmill in controlled circumstances.

Impact Level

Without a doubt, running outside has more impact. You’re running on rugged terrain, and while that has benefits for muscle growth and joint stability, it also comes with high impact.

That impact can go straight onto your shins and joints, causing tearing or other problems. Running on a treadmill still has impact, but newer models tend to have a shock system that sits just beneath the tread.

This helps to remove some of the blunt force that you would normally feel reverberate through your feet and legs when your feet smash down on the tread. Stabilizers help, but they won’t remove all of the impacts.

Still, the tread tends to be more forgiving than the asphalt and concrete outside. Outdoor terrain isn’t going to absorb shock; it all goes straight to you with every step you take.

Weight Control

Calories burnt on treadmill

Weight control is different from weight loss in many ways. We burn calories to lose weight, but we maintain a mixture of cardiovascular exercise and strength training exercise (resistance) to maintain our weight and control it from going up.

It’s true that most of your weight will happen in the kitchen, but what you do outside of it matters. In this regard, running outside is technically better because it engages your muscles and provides more resistance than a treadmill does, but that doesn’t mean it’s going to give any mercy to your joints.

In the long run, you need a mix of resistance training and cardio, and focusing on the higher impact method on a consistent basis can lead to long-term damage.

Find Your Perfect Cardio Routine

It depends on what you want to do, what the outdoor conditions are where you live, and if your joints are up to the task.

At the end of the day, running on a treadmill gets boring a lot faster than running outside does, but it’s measurable. It’s reliable.

You may be skipping the fresh air and sunlight, but the way that many states in the US have been reporting UV levels, it may be for the best to stay inside for your exercise.

Weigh the options and what you want, and how much your joints can currently tolerate, then make your decision. Either way, you’re actively working on your cardio health, and that’s what matters.