The best exercise programs for weight loss aren’t made of long, excruciating hours sweating through a tortuous workout session. One thing I am a witness to: short, intense, sessions get much more done.

Don’t do a bike or a treadmill at an easy pace for 35 minutes. Do it hard for 20 minutes.

Don’t go to the gym and take two hours to get your workout done, because you wait to get just the one machine you want, or stand gossiping with friends in between sets. Go quickly from set-to-set and finish it in under an hour.

Intensity can be a big ally in your weight loss program.

The reason comes from what happens to your body. You get on a treadmill and start going. 30 minutes later you finish. The display says you worked off 210 calories.

But science tells us it doesn’t stop there.

When you exercise, the activity elevates your entire metabolism. The more intensely you exercise, the more it elevates your metabolism and for a longer time.

So if you go out and take a slow walk, it will help, but the effect on your metabolism is small and only a little longer than your actual walk.

But go harder, walk faster, run, sprint, do stairs or whatever, and the exercise elevates your heart rate more, increases you metabolism MUCH more. The effect can last, in the case of aerobics, for more than an hour if it is intense enough. That is time your body is burning many more calories even while showering, changing clothes and eating breakfast.

In the case of intense weight training, the effect can last up to 18 hours. You use more calories sitting, walking, talking, eating and even sleeping. Suffer from a slow metabolism? Take part in 20 to 40 minutes of short, intense exercise and watch our metabolism take off.

That is one of the things that I’m happy I’m now able to do. When I started, my weight (over 300 pounds) and problems with recent injuries to my elbow and knee kept me from doing anything really intense. My only option was to do less intense workouts over a longer time period. But now that my weight is down to more manageable levels it is safe for me to take part in shorter, more intense workouts and get much better results.

Of course, be sane when working out. If you are new to healthy exercise, make sure you work with a professional trainer, or at least someone who is experienced working with people losing weight. And don’t forget to keep your doctor in the loop.