The answer comes from two sources. For our walking calorie calculators, I use the MET measurements conducted by Barbara A. Ainsworth. They measured the actual calories expended by people walking uphill at a brisk 3.5 miles per hour with those walking on flat, firm ground at the same speed. The difference was an increase of calories burned by 60% or by an additional 48 calories per mile for a 150 pound person. On the flats, that person would burn 80 calories per mile.
But unless you are on a treadmill, what goes up must come down. Do you lose all of that extra calorie burn because you were going downhill for part of your walk?
No, when going downhill you only burn 6.6% fewer calories per mile than walking on the flats. That means burning 5 fewer calories per mile for our 150 pound person. Overall, by adding a one mile uphill followed by a one mile downhill, that person burned 43 more calories than they would have walking a flat two miles.
But incline also makes a big difference. Not all hills are alike, they have different inclines (percentage grades). On a treadmill, you can accurately set your incline by 1%, 2%, etc. When walking outdoors, you need to use a tool such as MapMyWalk.com to map out your walks and see what the incline really is.
I can tell you from experience, that a 5% incline is a real huffer-puffer.
Using the equations from the American College Of Sports Medicine's Resource Manual for Guidelines for Exercise Testing and Prescription (courtesy of Wold Fitness Notebook) I find that:
- for every 1% of grade, you increase your calories burned by about 12% or about 10 more calories per mile for a 150 pound person.
- By the time you are at 10% grade, you are burning over twice as many calories per mile.
This is why hiking is often listed in calorie calculators as burning many more calories per mile than walking.
Go ahead, add some hills to your walking workout!
- How to Walk Uphill
- How to Walk Downhill
- Treadmill Hill Workouts
- Calorie Calculator by Distance
- Can You Really Trust the Calories Your Treadmill Displays?
Source: AINSWORTH BE, Haskell WL, Whitt MC, Irwin ML, Swartz AM, Strath SJ, O'Brien WL, Bassett DR Jr, Schmitz KH, Emplaincourt PO, Jacobs DR Jr, Leon AS. "Compendium of Physical Activities: An update of activity codes and MET intensities." Med Sci Sports Exerc 2000;32 (Suppl):S498-S516.
Photo © Wendy Bumgardner