Treadmill or Outside Walking - Which is Better?

Family Walking Through Flowers in Idaho
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Is it better to walk indoors on the treadmill or outside on a track, sidewalk, or path? The workouts are similar but have some basic differences.

Calories on the Treadmill vs. Outside Walking

Using a motorized treadmill with no incline, you may burn fewer calories per mile than you do outdoors. The moving tread does some of the work for you, and you have no wind resistance. According to research, you can overcome these by adding a slight incline, as little as 1%.

Holding onto the handrails will reduce calories burned further, and wreck your walking posture. It is best to train yourself to walk a speed you can sustain without holding onto the handrails.

Work More Muscles Walking Outside

Walking outside has its biggest advantage in challenging your balance and stability with all of the small obstacles, dodges, starts and stops. This will give you an advantage for distance walking as well as overall health as we age -- maintaining our stabilizing muscles. Here is what you face walking outside vs. on a treadmill:

  • Up and down curbs, steps, short stairways, and stepping over small obstacles. A little workout for your climbing muscles.
  • Sloped sidewalks and roadsides. A challenge to your balance muscles.
  • Dodging people, puddles, and poodles. A challenge to move side-to-side as well as forward.
  • Stops and starts at street crossings. A challenge to the muscles to come to a halt and to start from zero.
  • Treadmills only go uphill or level, only very rare models have downhill incline. Going downhill challenges muscles in a completely different way.
  • On the treadmill, the tread is moving and you may not be giving yourself a good push off with your back foot. Concentrate on doing this correctly on the treadmill.

    Distance Training Outdoors vs. Treadmill

    I recommend doing outside long distance mileage when training for a 10K, half marathon or marathon, rather than doing it all on the treadmill. Go ahead and use the treadmill for your within-week workouts of 30-60 minutes and to work on your walking posture and form. But for your long, slow distance mileage, do it outdoors.

    On a longer distance event, your muscles will begin to tire and you will need to remind yourself often of good walking form. You end up with aches in odd places as you "recruit" different muscles when your usual walking muscles tire. Outdoors training is more likely to be using those muscles for balance, stability, ups and downs than the smooth ride of the treadmill. You will end up with fewer aches after your long distance events if you have been doing your long slow distance training outdoors.

    Incline on the Treadmill -- All Uphill, No Downhill

    Treadmills can be useful for adding incline if you are in an area without hills, but I'll bet you can work some stairs into your workout if you look for them to help build the uphill and downhill muscles.

    This is the big problem with treadmills -- there is no downhill! You use different muscles to go downhill, and I never see a loop walking course where you only go uphill. You need to train those downhill muscles as well.

    Increased Mood and Mental Health Benefits of Outdoor Exercise

    A review of studies, published in February 2011, found increased benefits for mood and mental wellbeing. "Compared with exercising indoors, exercising in natural environments was associated with greater feelings of revitalization and positive engagement, decreases in tension, confusion, anger, and depression, and increased energy," according to the study abstract.

    Further studies showed walking in a park or natural setting decreased rumination and improved memory while walking in an urban setting did not. Studies in Japan found stress-relief benefits for walking in a forested area. You may want to add a park or green space to your daily walk.

    Advantages of Treadmill vs. Outside Walking

    Using a treadmill for your regular workouts is a great way to burn calories and give basic training to your walking muscles and practice your walking form.

    • Workout Programs: You may enjoy the pre-programmed workouts the treadmill offers to give you a controlled workout challenge. The treadmill may also have readouts for heart rate, calories burned, etc. which give you data feedback.
    • More Speed = More Calories Burned. Most people set their treadmill workout for time rather than for distance, and can often go faster on a treadmill due to lack of obstacles. More speed = more distance for the same amount of time = more calories burned than if they walked outside for set distance rather than for time.
    • Safety: If you don't have access to a safe walking route, a treadmill is a good substitute.
    • Weather: You can usually control the indoors weather, but never the outdoors weather.
    • Easy access to restrooms, water, and changing your gear.
    • Entertainment: Some of us are bored with treadmill walking, while others prefer watching TV or listening to their music indoors to walking outdoors.
    • Fewer excuses: If your treadmill is always available, you can't use excuses such as the weather, darkness, etc.

    Walking Indoors But Not on a Treadmill

    Other options for indoors walking include mall walking, indoors tracks, walking the halls and stairs, and marching in place.


    Jones, AM, JH Doust. "A 1% treadmill grade most accurately reflects the energetic cost of outdoor running." Journal of Sports Science 14(4)(1996): 321-7.

    J. Thompson Coon, K. Boddy, K. Stein, R. Whear, J. Barton, M. H. Depledge. "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, 2011; : 110203115102046.

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