Wednesday, April 13, 2011

Metabolic circuits and the science of calorie burning.

The latest installment in the ‘Ask the Physical Therapist’ from PT Dan – Losing weight is not enough.  We want to be lean and mean.  An alternate title to the following article could be “The mirror doesn’t lie.”

It was not long after Jim Fixx wrote The Complete Book of Running that jogging became a popular activity geared at improving health and losing weight. Hundreds of studies since that time have proven the many health benefits of aerobic activity to include controlling heart-disease, minimizing the affects of mental stress, and of course losing weight. But if shedding the pounds is what you’re after, modern science will point you in a different direction.

Any type of exercise will burn calories. If you run, you will lose weight, assuming you are eating a healthy calorie-reduced diet. But put those same people on a calorie-reduced diet and further modify their activity and the results can be astounding. In a controlled study done at the University of Connecticut, Dr Jim Volek, placed test subjects into 3 groups: Group one was placed on a calorie-reduced diet only, but did not exercise. Group 2 was placed on the diet and performed aerobic exercise 3 times per week. Group 3 was placed on the diet and performed a combination of aerobic and anaerobic exercises 3 times per week. Now you already know the results, but do you know why?

The results at 12 weeks revealed that all 3 groups lost nearly the same amount of weight; about 21 pounds per subject. But those who lifted weights shed 5 more pounds of fat than the other 2 groups. The weight that the lifters lost was almost pure fat. The weight loss of the other 2 groups was the result of a 15 pound loss of fat AND a 5 pound loss in muscle. Dr Volek summarizes, “for the same amount of exercise time, with the diets being equal, the participants who lifted lost almost 40% more fat.”

This research has been duplicated many times. Low-calorie dieters who don’t incorporate lifting weights will lose weight revealed as 75% fat loss and 25% muscle loss. The number on the scale will reflect the loss, but how do you look in the mirror? I have my patients use a scale only as a back up, and recommend that they base progress on how their clothes are fitting or how they look in their own reflection. There is fat loss and then there is leanness a measure of muscle density.

Science now reveals that weight training can burn more calories than originally thought-up to 71% more. Based on these findings performing one circuit of 8 exercises in 8 minutes at high intensity can expend 159-231 calories. That’s about the same amount of calories as running at a 6 minute pace for the same time duration!

Enter metabolic circuits; fast-paced, high intensity routines designed to alternate between upper and lower extremity exercises. This might be compared to bouts of sprinting, but while a sprint cannot be maintained for longer durations, by alternating muscles groups between upper and lower extremities you can sustain this level of activity for greater duration and while requiring only minimal rest. The result is resistance training while maintaining steady-state aerobic exercise. Best bang for the buck.

By incorporating 35-45 minute metabolic circuits three times a week, you can maximize weight loss and increase your dense muscle mass. You will be more efficient at burning fat, stronger in the sprints, and look better in the mirror-REWARD, REWARD, REWARD!

In Good Health-

Dan Lent-Koop, MPT, CHT


Dan Lent-Koop, MPT, CHT

Do you have PT questions for Dan?  Send them to: .


Katie said...

Great information :) This is why I like to incorporate Bodyrock workouts into my schedule, want to keep all my baby muscles!!

it's all about pace said...

Can you point me to a definition of this: "35-45 minute metabolic circuits"?

it's all about pace said...

PS - Good info thanks for sharing

runnergirl training said...

Excellent post! Keep up the good info sharing! :)

Anonymous said...

I love these articles! It's so great to have this info out there. I love finding news ways/reasons to torture my clients! They will say to me, have you been researching again ;) ?