Do Something Special This Week
As humans, we tend to relish in our scheduled lives. This structure is often required to optimize our time throughout the day as well as ensuring we accomplish all that we wish to in a timely fashion. This can also be detrimental, at least to a workout program. Without variety, a workout program will become less effective as the body adjusts to the repetitive stress placed upon it. With that in mind, why not mix up your exercise program this week.
If you are a runner, try biking one or two days this week. You will still receive the cardiovascular benefits in addition to using your legs in a manner that they are not accustomed to, which will ideally lead to a gain in muscle tone and endurance. Many athletes use this technique, it is called "cross training", and it can be highly effective.
Perhaps you are a weight lifter and have been doing the same exercises for several weeks. Why not try something that you normally don't do? If you do flat bench press every week, try replacing it one day with a series of push-ups. You might be surprised how difficult push-ups can be to perform when you do not execute them regularly. The body adapts far too well if one is executing the same exercises week after week. Throwing a curve-ball at it will give the body something new to handle.
Regardless of what you do for your workouts, do something out of the ordinary this week. Just make sure you read up thoroughly on the exercise or activity as to avoid injury as well as to receive the maximum benefit with trying something new.