Sunday, October 12, 2008

The Cardio Weight Loss Lie

Cardio works for fat loss...as long as it is high-intensity cardio. Check out this recent study...
Researchers at the University of Virginia assigned 27 obese women (average age 51 years) to one of three groups...

1) No exercise training/control

2) 5 days per week of Low-intensity exercise (LIE) - gotta love that acronym...truly represents the "slow cardio lie"

3) 3 days per week of high-intensity cardio exercise (HIC) plus 2 days per week of LIE

The high-intensity cardio was done above the Lactate Threshold.

Training at your Lactate Threshold is a painful experience, because that is the intensity level where lactic acid will start to accumulate in your blood. It means you are producing more lactate in your muscles than you can get rid of (it usually travels from your muscles to your liver or back into your muscles to be broken down even more).

Other exercise experts might use the phrase Anaerobic Threshold or Onset of Blood Lactate Accumulation to describe your lactic threshold.

An experienced exerciser can train at this level for about 30 minutes. But again, it is uncomfortable. Actually, that's not even the right word...it's downright brutal. This is often about 80% of your VO2max or even 85% if you are well trained.

In this weight loss study, the subjects didn't exercise for time, but instead they exercised in every session (both LIE and HIC) just long enough to burn 400 calories...so no group burned more calories than the other over the entire program. It's just that the HIC did so faster in 3 of the workouts each week.

Reference
Med Sci Sports Exerc. 2008 Oct 8. Effect of Exercise Training Intensity on Abdominal Visceral Fat and Body Composition. Irving BA, Davis CK, Brock DW, Weltman JY, Swift D, Barrett EJ, Gaesser GA, Weltman A.

And the results showed...

High-intensity cardio kicked the LIE's butt.

Actually, it also showed that LIE didn't do anything. The subjects in the Low-Intensity Exercise group did not lose fat. Boooo to low-intensity cardio.

On the other hand, the HIC (high-intensity cardio) group lost a significant amount of abdominal fat.

Once again, research shows that...

a) Exercising harder results in more fat loss in less time

b) Hard exercise burns belly fat

c) Low-intensity cardio doesn't do much for fat loss

You probably know I'm a big fan of interval training for fat loss, but once in a while I also throw in "high-intensity cardio" (its used every week in the Turbulence Training 6-Month Bodyweight Manual and it's used in the Bodyweight Cardio program).

You'll probably see it used more often in my programs, given these results. So if you are interested, you can add HIC to your program by doing it once per week in place of interval training.

But there is ONE problem...to burn 400 calories you will need to exercise for a long time, at least 30 minutes - if you are fit...and longer if you are unfit. But if you are into it, go for it, just remember to self-monitor your body for any symptoms of overuse injuries, and as always, TRAIN SAFE.

I'll give the last word to the researchers who state, "The present data indicate that body composition changes are affected by the intensity of exercise training with HIC more effectively for reducing total abdominal fat and subcutaneous abdominal fat in obese women."

Train hard,
Craig Ballantyne, CSCS, MS

1 comment:

Erik Ledin said...

CB

Are you aware of the nutrition b/w groups? Was that controlled as well?