Safety / Injuries

Treadmill Running vs Outdoor Running: Find Your Ideal Run

ISSA, International Sports Sciences Association, Certified Personal Trainer, ISSAonline, Treadmill Running vs Outdoor Running: Find Your Ideal Run

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Some people dread running on the treadmill. Others find it hard to drag themselves outside for a run. Both outdoor running and treadmill running are effective forms of exercise—and both have their own unique benefits. 

So, which one is optimal for your clients?

We’ll explore the benefits of treadmill running and outdoor running so you can decide for yourself which one is ideal for your running clients. 

Benefits of Outdoor Running

Being outside in nature is healthy, regardless of whether or not you’re exercising. Pair that with extra endorphins from a workout and your clients might just find that outdoor running is their preference. Here are a few of our favorite benefits of outdoor running:

1. The View

If you’ve spent any time on a treadmill, you know it can be a challenge to workout while staring at the same wall, clock, or tv. It’s demotivating for many people. 

One of the many pros of outdoor running is the changing scenery. Stretches of the beach, forest trails, varying neighborhoods, skyscrapers, or patches of open fields can make it feel like time is passing faster—a common desire for individuals during their workout. The visual stimulation is one of the reasons many people prefer outdoor running over the treadmill.

2. It’s FREE

Other than some good running shoes and appropriate attire, you don’t need to have anything to run outside. There are certainly many gadgets that can make a run interesting (headphones/media player, heart rate monitor, etc.), but those things aren’t required to get outside and run!

Treadmills, on the other hand, typically require monetary investment. Whether your clients own their treadmill or pay a monthly fee for access to their local gym equipment, there’s a payment involved. 

3. Race Day Simulation

Outdoor running is ideal for road race prep. Navigating potholes, turning right and left, uphill and downhill (incline and decline), and managing wind and weather are all intricate components of a race that your clients can only get from an outdoor run.

The only wind resistance your clients will get on their treadmill run is the light breeze from the treadmill’s built-in fan. And, although a treadmill can simulate uphill running, it doesn’t prepare your clients for downhill running or turns. 

4. Vitamin D

Vitamin D is an important micronutrient for the human body. Clients can get Vitamin D from food consumption (flesh of fatty fish, egg yolks, cheese, and some fortified foods), and supplementation, but the body also produces Vitamin D when exposed to sunlight. Research suggests being outside for as little as 30 minutes, twice a week, without sunscreen may be enough sun exposure for sufficient Vitamin D. So, even short outdoor runs on a sunny day can be valuable.

Clients may believe using a treadmill next to a window will provide a similar effect. However, the UVB radiation that penetrates the skin and converts to Vitamin D3 doesn’t penetrate glass (1).

Benefits of Treadmill Running

Some clients would much rather hop on the treadmill for their run! There are several benefits to using a treadmill instead of running outdoors! The following list includes a few of our favorites: 

1. Perfect “Weather”

Your clients can use a treadmill with six feet of snow on the ground, an outdoor temperature of 100+ degrees, and during a pitch-black night or heavy rainstorm! No excuses to miss a workout!

Outside running is still possible in these types of conditions, but they typically have to be carefully navigated with the right attire, hydration, and safety methods. 

2. Controlled Running Speed

Unless your clients have a fancy gadget that calculates their pace or they’ve carefully measured their running route, it can be difficult to determine their exact pace during an outdoor run. On the other hand, the pace on a treadmill can be easily controlled. 

Check out this ISSA blog post for more on how to improve speed and endurance.

3. Safety

Treadmill running is a great way to get in a workout while minimizing certain safety risks. This doesn’t mean your client can’t get hurt on a treadmill—a missed step, an untied shoelace, or a loss of balance could be incredibly dangerous for a client. But, trail or road running has the potential for many more hazards that could cause injury to your client!

A late-night workout, unknown surroundings, and intense weather are non-issues running indoors on the treadmill. Plus, there aren’t any passing bikers, drivers not paying attention, or debris to watch for. 

4. Slightly Easier

The treadmill belt assists runners a bit, making the workout a little easier. However, research suggests if your client is running between 6.5-11 mph, a 1% treadmill incline closely mimics an outdoor run (in terms of energetic cost) (2). 

So, if you choose not to adjust the incline on the treadmill, clients may get a little bit of boost from the equipment. 

5. Workout with Friends of All Fitness Levels

Does your client have a buddy that helps them stick to their exercise goals, but their fitness levels are different? Whether your client is faster or slower than their friend, they can walk, run, or sprint side by side regardless of their skill level. It’s much harder to do this outdoors unless they find a runner willing or able to run the same pace as them. 

So, which one is better… the treadmill or outdoor running? 

As with many exercise options, it depends. It’s important to take into consideration your clients’ safety, goals, and training needs. But ultimately, personal preference is the best way to determine the ideal running experience for each person. Activity in any form is better than the alternative…inactivity. So, when clients find a style they can stick to, in alignment with their goals, and is enjoyable, it’s the ideal route for them.

Plus, it’s not uncommon for runners to use both outdoor running and treadmill running depending on weather, location, availability, mood, etc. 

Looking for additional ways to help your clients improve their run? Become an ISSA Corrective Exercise Specialist and increase performance by uncovering potential injuries and limitations from improper movement patterns, poor posture, and limited range of motion. Plus, you can learn from the comfort of your home!



  1. National Institutes of Health. “Vitamin D Fact Sheet for Health Professionals.” Ods.Od.Nih.Gov. 2020.
  2. Jones AM, Doust JH. “A 1% treadmill grade most accurately reflects the energetic cost of outdoor running.” J Sports Sci. 1996 Aug;14(4):321-7.

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