New Fat Loss Study

A new study* published last month in Medicine & Science in Sports & Exercise showed really interesting result on effect of exercise training and abdominal fats.

In the study, 27 obese women (average age 51 years) completed 16-week of aerobic training in one of three aerobic exercise groups...
1) No exercise training/control
2) 5 days per week of Low-intensity exercise training (LIET)
3) 3 days per week of high-intensity exercise training (HIET) (above lactate threshold level)plus 2 days per week of LIET.

Exercise duration for all the subjects were adjusted so that every one burns 400 calories in each session. In another word, the LIET group would have exercised longer per session as compared to the HIET group.

And the results showed no significant changes in the LIET group. On the other hand, the HIET group lost a significant amount of abdominal fat. So the study reveals 3 things:

1. Exercising harder results in more fat loss in less time


2. Hard exercise burns belly fat


3. Low-intensity cardio doesn't do much for fat loss

Here is the interesting part, all the women in the study burned the same amount of calories after 16 weeks of training, the old-school thinking would probably expect same fat loss results. So the differentiating factors should probably exist outside the training time. Is it because high intensity exercise induces changes in post-workout fat metabolism (like increasing lipolysis and its related enzymes in adipose tissue) but low intensity exercise dosen't? This would be up to the scientists to conduct more research to find out.

This study verifies what I always advocate for my clients, that if they want to burn fats, they should exercise hard at higher intensity, instead of wasting their precious family/social time to hog on the treadmill at low intesity for hours!

Inspired to do some 'HIET" cardio to burn that annoying tummy fat off right away? Take note that to train at your lactate threshold (as in the HIET group in the study) is often about 80% of your VO2max or even 85% if you are fit. Training at your lactate threshold is a painful experience, as that is the intensity level where lactic acid will start to accumulate in your blood, which will in turn cause burning aches in your muscles. So remember to self-monitor your body to train safe and look out for any symptoms of overuse injuries.

*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.