Running on an Incline vs. Flat

A flat treadmill helps you learn to go fast.
i Chris Clinton/Photodisc/Getty Images

If you plan your running route to avoid hills or never touch the incline button on the treadmill, you might want to rethink your workouts. While running on a flat surface burns calories and trains your heart, incline running also increases your muscle strength and power. Hills can help you build greater aerobic capacity and builds a more efficient stride. Because it puts great demands on your body, you shouldn’t run hills every workout. Take advantage on non-hill days of the benefits a flat road can provide.

Muscle Recruitment

Dr. Matthew Rhea, Director of Human Movement at A.T. Still University, performed research for Free Motion Fitness in 2008 that found exercising on inclines of more than 15 percent activated the leg muscles about three times as much as exercising on a flat road. An earlier study published in “Medicine and Science in Sports and Exercise” in June 2000 found that running sprints on a 30 percent incline enhanced the workload on muscles key to running significantly more than running on a 0 percent grade. This means you build greater muscle strength and power when running on an incline so that when you run on a flat road, you can go faster more efficiently.


Running on an incline can diminish injuries. Rhea’s research showed that walking at 3 mph on an incline of 12 percent yielded the same heart rate as running at 6 mph on a flat speed. If you cannot run due to injuries, high speed incline walking is a lower impact alternative for you. Flat road running can also aggravate shin splints or knee pain. Running on an incline reduces that stress.

Calorie Burning

Running up a five percent incline on a treadmill burns about 100 more calories than running on a flat road, says “Shape” magazine. The exact difference in how much you burn depends on your speed, body weight and running fitness levels. Rhea’s research found that going slower up an incline utilizes a greater amount of fat. Running fast on a flat road still burns calories, but more of them come from carbohydrates.

Running Efficiency

Your form going up an incline is not really different than running on a flat road, notes Rick Morris, author of “Treadmill Training for Runners.” Because long strides uphill can cause a braking effect, you need to stick to short, quick strides. A short, quick cadence also makes you efficient on a flat road. Flat road running does have value in helping you hone speed. You can get used to turning your legs over quicker so that when you face a flat race, you have the muscle memory.

One Percent

To run the equivalent of an outside flat road on a treadmill, set your incline at 1 percent. When you run on a treadmill, you don’t have wind resistance which has an energy cost of about 7 percent, says Greg McMillan, M.S. in a January/February 2009 issue of “Running Times.” When you run on a treadmill, the belt runs under you so you don’t have to push off in the same way you do when outside. A treadmill is also a smooth surface, so you don’t have to adjust for micro terrain changes outdoors that slow you down slightly.

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