New findings suggest that it pays to alternate short bursts of high-intensity exercise with gentle recovery during workout regimens at least once a week.

Although this alternating technique, called interval training, has existed for decades, a new study has confirmed that it can dramatically improve cardiovascular fitness and the body's fat-burning capabilities.

Researchers asked eight college-age men and women to sprint for 30 seconds, and then either stop or pedal gently for four minutes. After only two weeks of this interval training, 75 percent of them doubled their endurance.

A control group, which did not do any interval training, showed no improvement in endurance. The marked improvement in the interval training group was even more startling because the volunteers were already fairly fit.

Another study also showed that interval training enhances the body's ability to burn fat. Eight women in their early 20s were told to cycle for 10 sets of four minutes of hard riding, followed by two minutes of rest. After two weeks, the amount of fat burned in an hour of continuous moderate cycling increased by 36 percent, and their cardiovascular fitness improved by 13 percent.

Dr. Mercola's Comment:

For most of my life I have focused on endurance aerobic training. When I was competing in college and for the next 15 years, I used to do interval training, but since I haven't competed for over 15 years, I stopped those workouts.

However, I have become ever more impressed with the convincing evidence of the usefulness of this technique. There is abundant new scientific evidence, like this study, that clearly demonstrates there are enormous benefits to interval-type training.

Personally, I now only run once a week and so do sprint training combined with pull-ups, dips, and singles tennis whenever I can find someone to play with. I just love tennis because it is, without question, the most fun I have when I exercise, and it gives a great opportunity to move in so many different directions.

This was motivated by Al Sears, MD who reawakened me to the value of interval training with his take on it which is called the P.A.C.E. program.

I also recently started Russian kettlebell training, which is also a very short high-intensity, interval-type activity. DragonDoor is the organization that introduced Russian kettlebells and is where you can find out more about them.

I now firmly believe that although endurance cardio training is important, it really needs to be part of a more comprehensive program that includes short bursts of activity at very high intensity that is individualized for your specific fitness level.

The new evidence suggests that this may actually provide MORE protection against heart attacks than long durational aerobic type exercises.

Another major benefit of this approach is that it radically decreases the amount of time you spend exercising, while giving you even more benefits.

It would be wise to have clearance by your physician if you are not in good shape before embarking on a program like this. However, you could start simply by walking and progress at your own pace.

But this is a technique that should help nearly anyone who uses it.

The take-home message?

Don't rely solely on cardio. You will need to incorporate interval-type training along with strength training to develop a far more rounded and comprehensive exercise program.

You will be very pleased with the results and perhaps even more pleased with the free time you have if you have been a slave to hour-long cardio workouts.

Related Articles:

How to Get Off Your Fat and Get the Fat Off!

Too Much Exercise is Just as Bad as Not Enough

Jane's Jungle Workout