It used to be that incline on a treadmill was a bonus feature. However today, most motorized treadmills come with an elevation option. The difference seems to be in the amount of elevation available.

If you're looking for an economy treadmill (under $1000) you'll probably find most treadmills only come with a 10-12% incline (however that can be enough for most people - especially for those new to treadmill exercise).

When you get into the mid-priced treadmills ($1500+) you'll start to see elevations of 12-15%. And in most premium treadmills you'll find elevations of 15%.

If you're in top shape and really want a challenge, then you'll probably want a 15% incline. However if you just want a treadmill for gentle walking, 10% might suit you perfectly.

Of course, the mother of machines is the incline trainer. This is a treadmill that also gives you much more elevation than normal treadmills - up to 30%.

You've probably heard about the Bowflex Treadclimber. The Bowflex Treadclimber is a hybrid stair climber and treadmill. TreadClimbers have two separate, smaller treadmill belts (one for each foot) that you walk on. These individual belts also move up and down, meeting every step you take.

Nordic Track also has an incline trainer available - called the Nordic Track X5. This machine has only one treadbelt (like a treadmill) and offers inclines of up to 30%.

An incline trainer is way more than most people need. But if you want to burn as much as 500 calories in 20 minutes, you can do it with an incline trainer.

While incline trainers are excellent for burning calories, the downside is you're going to pay for them. Prices start at around $1600 for basic models. Because of this, these machines are used mostly in commercial settings like gyms or office fitness facilities.

So why the big deal about treadmill inclines?

Walking on an elevation can help super-blast your calorie burn. You can burn up to twice or even 3 times the calories by walking on an incline vs. walking on a level surface.

Plus if you're looking to build intervals into your workout, walking on an elevation for 30 seconds to 2 minutes can be a great way to interval train and boost your post workout calorie burn.

So in general an incline on a treadmill is a great tool to have. It can help you get in shape and burn calories much faster than simply walking on a level surface.

Regardless of which elevation percentage you choose, just remember to wear high quality running shoes and enjoy your workout!