Whiles it is true that using the treadmill incline feature can be a great way to boost your treadmill workouts; it can also be a dangerous tool especially when not used correctly. If used too often or incorrectly it can hamper your workout and fitness goals.
The average treadmill will have an incline level range of between 0-15 percent. In general most beginners should begin at level 0-1* Zero being flat and 1% being the next level up, as a beginner there is no need to go above a 5% level incline. A beginner will get a better workout by running at a faster pace at a low incline level than at a slower pace at a higher incline level
Running on an incline is the theoretical equivalent of running up a hill but it is not the same, the outdoors offers the elements and uneven ground which makes it a much tougher exercise routine. One should not equate running on the treadmill with an incline as equivalent to running outside up and down hills. The incline on the treadmill also has one fall back and that is, it can not give you the experience of running down a hill, which by itself is a very tough weight loss exercise.
Always be cautious when running on the incline on the treadmill, be sure to keep your form right and never over do it! The best way to ensure safety is to run at an incline of 0% for 2 minutes followed by a 3 minute run of an incline at 5%, you keep alternating between the two and you will be super sit and injury free in no time. If you do intend to use the treadmill to lose weight, be sure to run outside when you can. For the days you can not run outside, you may use the treadmill to complete your fitness program.
In summary it is always best to run outdoors in a hilly area and if you can not run outdoors you can use the incline on the treadmill to mimic running up hills.