If you're impatient to see some improvement in your fitness level, try making a significant change in your workouts. Switching from your usual activity to another can work different muscles -- and therefore give you different results. Example: If your cardio workouts have been on machines (e.g., treadmill, stationery bike), you might shift to tennis or basketball.

But be careful: Significant change does not mean taking on more than your body can handle. Your goal is to make a distinct change in the TYPE of exercise, not the intensity.

By making a change that is sensible and safe, you could start seeing results in as little as two weeks.