Intensity Propensity: The Importance of High Intensity Exercise

High intensity exercise burns just as many calories (in less amount of time) – but many more in EPOC (excess post-exercise oxygen consumption); therefore, intense exercise is the way to go for fat loss and health.

The theory rests on these points:

1. The most important factor for weight loss is total caloric expenditure.

2. Intensity has a greater influence than duration on caloric expenditure.

3. The initial high intensity exercise will rapidly deplete glycogen stores which will increase the amount fat oxidation during the second half of the exercise – the 15-30min portion of moderate intensity. (I am implying an exercise period consisting of 15-30 minutes of intense exercise followed by 15-30 minutes of light.

It is well known that at intensity levels less than 65% (approx) the percentage of fat oxidation is greater than that at intensities above 65%. However, notice it is the percentage that is greater, this does not necessarily translate to greater fat loss after months and months of exercising. For example if I burn 500 calories in one exercise bout and 400 calories came from fat, then %80 percent of my energy expenditure came from fat. If I burn 800 calories by upping the intensity and still only burn 400 calories from fat, then only %50 of my caloric expenditure came from fat- but I burnt a lot more calories.

Extreme example of faulty low intensity exercise -> Fat, most likely, contributes the most toward your total energy expenditure during sleep; however, you are hardly burning any calories and sleeping is not an effective way to lose fat.

Also, higher intensity can lead to more hormone release, which in turn can lead to more muscle gains (or muscles loss - more on this later)

Above all, be safe. Don't jump into high intensity workouts - ease into them by slowly increasing the difficulty of your exercise. If in doubt find a well qualified trainer/friend who can teach you good body mechanics so you don't hurt yourself.

Whens the last time you worked out?

-Will