Monday, November 24, 2014

"Training in the Zone", Does it Work, After All? Middle-Aged Women Lose 8% Fat in 10 Weeks, Effortlessly. Plus: Weight Loss & Gain Patterns in African Americans

Training in the fat burning zone works. But the claim that it was the best way to lose weight is certainly subject specific.
Time for a brief overview of the latest research on obesity, it's health consequences and potential causes. I mean, you don't really believe that the result of a recent review in Nutrition Reviews is more than the sum of biased research that appears to hilariously suggest that "grain products are more protective than fruits and vegetables" (Fardet. 2014). We have heard that way too often and just like the claim that "dairy/milk products have a neutral effect on the risk of diet-related chronic diseases, while red/processed meats tend to increase the risk" (Fardet. 2014) we have not yet made any progress in out battle against obesity, type 2 diabetes, and various types of cardiovascular disease and cancer.
It does not always have to be HIIT, ladies and gentlemen, trainers & trainees

Never Train To Burn Calories!

Tabata = 14.2kcal /min ≠ Fat Loss

HIIT vs. LISS - Efficiency?

Making HIIT a Hit Part I/II

Making HIIT a Hit Part II/II

HIIT Ain't For Everyone
  • Training in the (fat) burning zone: In a recent study scientists from the University of Southern Queensland were not able to demonstrate the superiority of training at an intensity that equaled their thirty 45-59 year old female subjects maximal fat oxidation intensity (Tan. 2014). But this was not due to the fact that this form of training is not effective, but rather a result of the five 1h sessions of steady state cardio in "the fat burning zone" was the only form of training tested.

    What the researchers did find, though, was that the exercise group obtained significant decreases in body mass, BMI, body fat % and abdominal fat mass, as well as the concentrations of triglycerides, serum leptin and blood glucose.
    Figure 1: The changes in body composition with 5x / week 1h of cardio in the zone in the absence of dieting were quite impressive in this 10-week study (Tan. 2014)
    The activity of lipoprotein lipase was increased in trained participants, there were no changes in these variables in the Control group.

    In addition, there was no significant change in daily energy intake for all participants before and after the experimental period. In this particular study, the often derided cardio training "in the zone" did thus work its often doubted magic and shed 8% of the subjects body fat without dieting.
  • Patterns of weight change in African Americans: Even more so than the US citizens with Caucasian ancestors, the group of African Americans is threatened by ever-increasing obesity rates. By trying to identify broad categories of people with likely different program outcomes in a large weight loss intervention study, scientists from the Center for Clinical Epidemiology and Biostatistics at the University of Pennsylvania Perelman School of Medicine tried to identify treatment approaches that would better position program enrollees for success.

    Figure 2: Obesity is not an African American exclusive problem in the US, but the obesity rates - specifically for the women - are still higher in AA vs. CC citizens (Ogden. 2014).
    What the researchers found was that there are three general patterns that distinguish the "big losers" in their program into people with a...
    1. mean weight loss of approximately 2 kg (n = 5 519); 
    2. mean weight loss of approximately 3 kg at 1 year, followed by 4 kg regain (n 5 61); 
    3. mean weight loss of 20 kg at 1 year followed by 4 kg regain (n = 524).
    In a final multivariate analyses, were also able to show that a higher BMI predicted having pattern 2 (+10%) or 3 (+42%), and higher dietary fat scores were predictive of a lower odds of having patterns 2 (-63%) or 3 (-67%).

    While a weight regain of 4kg sounds huge - losing 20kg within one year and regaining only 4 means that you still lost 16kg, which is not bad and speaks in favor of the "the fatter you are, the easier you can lose tons of weight" truism. Moreover, the association with high dietary fat intakes underlines that the often cited benefits of eating more fat will occur only if the carbohydrate content of the diet is severely reduced. All in all, the study results are yet far too general to use them to deduce better weight loss prescriptions. 
Suggested read: More Than 3x Higher EPOC Induced Energy Expenditure With HIIT vs. LISS! But Does That Really Matter? Plus: Why Headlines Like This May Compromise Your Progress | read more.
Bottom line: It will certainly depend on the amount of exercise, the physical fitness and the degree of overweight, whether or not classic "fat burning" training works or not. The results of the study Tan et al. present in their latest paper, however, clearly indicate that trainers and trainees (esp. those who still have a relatively long way to go to get back to a normal body weight) should not underestimate the benefits of this derided type of exercise.

Speaking of "to underestimate", one should not underestimate the power of fast weight loss either. The African American participants who lost 20kg of body weight in the first year of the studies, Morales et al. reviewed did after all lose 14kg more weight than the "healthy losers" with their pathetic 2kg weight loss per year and no weight regain.

A result that should remind you of the recently published evidence that "slow and steady" has no significant advantage over rapid fat loss (Purcell. 2014; Yamada. 2014).
  • Fardet & Biorie. "Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/ meta-analyses and systematic reviews." Nutrition Reviews (2014).
  • Morales, Knashawn H., et al. "Patterns of weight change in black Americans: Pooled analysis from three behavioral weight loss trials." Obesity (2014). 
  • Ogden, Cynthia L., et al. "Prevalence of childhood and adult obesity in the United States, 2011-2012." JAMA 311.8 (2014): 806-814. 
  • Purcell, Katrina, et al. "The effect of rate of weight loss on long-term weight management: a randomised controlled trial." The Lancet Diabetes & Endocrinology (2014).
  • Tan et al. "Positive effect of exercise training at maximal fat oxidation intensity on body composition and lipid metabolism in overweight middle-aged women." Clin Physiol Funct Imaging (2014).
  • Yamada, Tomohide, Kazuo Hara, and Takashi Kadowaki. "Abstract P084: Influence Of Amount And Rapidity Of Weight Loss On The Risk Of Subsequently Regaining Weight And Drop-out From Treatment Among Patients With Severe Obesity Dieting In Hospital Without Bariatric Surgery." Circulation 129.Suppl 1 (2014): AP084-AP084.