If your workout routine involves a treadmill, consider this: is your routine a bit stale? Are you finding that what once was a challenging workout is now a bit, well, easy? That'll happen as you adjust to your new fitness level. There's only one solution: Make it harder.

When you're working out on the treadmill, there are a number of ways to make it more difficult. You can up your speed, work out for longer periods of time or add some ankle weights. But one of the most effective ways to amp up your workout is to increase the incline. Start small; add just one level of incline, and keep it at that level until you find it easy, then increase again by one level.

Remember: A workout that's easy to do probably isn't doing too much to improve your fitness or your body.