"An incline significantly increases the amount of effort your body must make in a workout. This means more calories burned and saying bye to fat," said Chadwell. It's about creating a bit of resistance — you use the gradient increase to force your body to work harder, burn more calories, and slim your belly.
It also helps to mimic outdoor workout conditions. According to one study, a one percent treadmill grade most accurately reflects the energy spent when running outdoors.
Most treadmills will increase in half increments, so you could walk or run at a 0.5, 1, or 1.5 percent grade, all the way up to 12 percent or more depending on what equipment your gym has and your level of expertise.
Image Source: POPSUGAR Photography