The age-old theory of staying in the gym for 45 minutes or more is being challenged, with a new theory that suggests you get in and out of the gym in 30 minutes or less. This is an interesting and effective way to approach your fitness goals - less time spent exercising, but with a higher intensity.

To get results from exercise, intensity and frequency are more important than duration. In fact, intensity and duration are inversly related. So keep it short and intense and see the results increase exponentially. If you are running short on time, like most individuals are, then exercise sessions of a shorter duration make sense.

Shorter, more intense sessions are fun and invigorating. A 20-30 minute strength training workout is a lot more convenient and energizing than trying to find 60-75 minutes on the treadmill. It is more fun, stimulating and energizing and results can be magnified with a workout buddy.

Scientific experiments have proved that this is an effective strategy for weight loss:

? More Minutes. Studies have shown that females who broke down their exercise sessions to 10 minutes, 3 times a day, 5 times a week lost more weight than women who exercised for 30 minutes at a time, 5 times a week. Ironically, breaking down the exercise frequency (training more than once a day, but for shorter periods) yields more results than if you were to do the exercise all at the same time. Short, intense sessions boost metabolic rate, which stays elevated longer as compared to low intensity, long duration sessions.

? More Miles. In a University of Nebraska-Kearney study, overweight walkers who did two 15-min bouts, 5x/wk, nearly doubled their weekly mileage compared with walkers who walked 30 min, 3x/wk.

? Less Dropout. Twice as many people stuck with more, short workouts as those who stuck with fewer long ones. Interesting, considering that the short workout group put in more days (5 vs. 3) and committed more time weekly to exercise (150 min. vs. 90 min).

? More Calorie Burn. Whether you do your workouts all in one shot or break them up, you burn about the same amount of calories. But what happens AFTER is a different story.The calories you burn after a workout may be slightly higher if you break up your workouts.

? Better Recovery. A long, tedious, 60-90 minute workout will burn you out physically and mentally fast. Concentrating your workouts into 30-35 minutes allows your muscles to recover between workouts, and to work your body more frequently.