Sunday, April 29, 2012

Every Dog Has His Day: Dr. Oz Was Right, Exercise Does Not "Just Make You Hungry", But Reduces Energy Intake!

Image 1: If I had to chose between the man on the left and the one on the right as my "dietary adviser", I would probably chose the right guy - I would not want him as a fitness coach, though ;-)
At least for those of you, for whom this is not their first visit at the SuppVersity, the term "physical culture" should sound somewhat familiar. I have "stolen" it from my friend Carl Lanore, the host of Super Human Radio who (I am sorry Carl) has probably "borrowed" it from someone else (maybe Randy Roach?)... in the end, it does not matter who coined the term; for me, it embodies the notion of working out for life - not just to look good on Spring Break. To embrace a healthy diet and to value your body in a non-narcissistic fashion. It is this "I am in this for life" mentality that will eventually pay off - and it is the lack thereof which renders all short-term attempts to "lose weight" or "pack on muscle" futile.

It does not take 8 days, 8 weeks or 8 months, it takes a lifetime

An, in my humble opinion, extremely counterproductive, claim that is coming up time and again, when people are debating the fallacy of the "calories in vs. calories out"-hypothesis (on the Internet, in books and even on Dr. Oz ;-) is that a fundamental reason that this equation would not hold, was that "exercise will just make you hungry". Proffered mostly by people who have never followed any type of consistent exercise regimen (or only in the presence of a calorically or macronutrient restricted diet), the central proposition of this claim is that you better not move your ass if you want to lose weight, because this will make it even more difficult for you to adhere to the currently en-vogue low-better-no carbohydrate diet, or otherwise restrictive diets.

I personally do not doubt that the latter is the case, what I do yet doubt is that long-term dieting and the avoidance of any type of allegedly hunger-inducing exercise, which would be the logical implication of the proffered argument, ist the be-all and the end-all of getting or staying in shape.

Exercise reduces not induces cravings and energy intake

I have broached this issue in previous blogposts, already (e.g. "The Female Weightloss EDC"), but none of the previous studies indicated so conclusively as the study that STRRIDE AT/RT that physical activity alone and in the absence of dietary restrictions can offer a long-term solution to weight loss and improved body composition.
Where is the Step by Step Guide (SBSG)? Just in case you are asking yourself where the next / last installment of the "Step by Step Guide to Your Workout Program" is - after all, it is Sunday! - I would invite you to let me know what you believe is still missing before I conclude this series. While my decision to postpone the next installment of the SBSG was partly related to my busy schedule, I am also not sure, if you do actually need more guidance or would agree that all the series still needs is a summary of the individual steps and a conclusion. If you disagree or have specific issues you want to be addressed in what will probably become the last installment of the SBSG, feel free to leave a comment either here, in one of the respective posts or even on the SuppVersity's Facebook wall. Thank you!
In the study that was conducted by researchers from the Duke University Medical Center and the University of North Carolina, and the results of which have just been published in the Official Journal of the American College of Sports Medicine, a group of overweight/obese sedentary dyslipidemic men and women nN = 117) were randomized to one out of the following three exercise programs:
  • aerobic training (medium to high intensity steady state) of choice (treadmill, elliptical trainers, and cycle ergometer) with a total volume that would equal the workload of a 12-miles run / jog / walk (depending on fitness level) at a  VO2Max of 70-80% (n=39)
  • resistance training (full body workout, linear progression in 5lbs steps, when subjects were able to perform the prescribed number of reps) 3x per week, 3 sets a 12 reps (n = 38)
  • combined treatment (aerobic + resistance) with aerobic and resistance training on seperate occasions (n = 40)
While the resistance training sessions were supervised (or conducted with a training partner) and the adherence to the aerobic exercise regimen was controlled by hear rate monitor logs, there were no dietary restrictions of any sort.
Figure 1: Reduction in energy intake in response to the exercise regimen as assessed by average of data collected using
3-day records and 24 hr diet recalls (questionnaire) or food frequency (left) and changes in macronutrient composition (in %) of total kcal (data adapted from Bales. 2012).
And still - or rather therefore? - it does not take a rocket scientist (or science journalist ;-) to see that the caloric intake was statistically significantly reduced in all three groups.
Note: Although the quantity of the changes in macronutrient composition may be negligible, it is quite interesting and sort of revealing in terms of the interpretation of other study data, that there was a huge discrepency between the "recalled" (3-day records+24h recall) macronutrient intake of the study participants and the calculated one (based on food frequency). The ostensible overestimation of protein intake and the profound underestimation of the carbohydrate intake, in the presence of an almost "spot on" awareness of the fat intake, are telling as far as the accuracy of epidemiological studies using similar 3-day records+24h recalls to elicit the macronutrient composition of the diets of certain populations.
It is also interesting to note, that the metabolically most demanding exercise regimen, the combined protocol, exerted the greatest reduction in energy intake (not energy balance!). A result that appears to confirm the recommendation I have made in the "Step by Step Guide to Your Own Workout Regimen" to rather train frequently and short, than just once or twice a week in excess - not only, but specifically, when your main focus is still on the reduction of body fat (cf. "Fat Loss Workout Template").

Exercice more, eat less, gain muscle and lose fat - stick to it and it works

Since we are not dealing with a prescribed caloric restriction, but with a voluntary reduction in caloric intake in previously sedentary, overweight subjects in response to an obligatory exercise regimen, it stands to reason that this protocol elicited beneficial changes in body composition, which were probably due to the meticulously controlled adherence to the the aerobic and resistance training sessions, not correlated with the subjects' adherence to the aerobic (R = -0.198; p = 0.227), resistance (R = -0.109; p = 0.516) or combined (R = -0.188; p = 0.245) training programs.
Figure 2: Changes in lean body mass (LBM), fat mass (FM) and total body weight, as well as reduction in energy intake (in kcal per kg) of lean body mass in the 17 overweight / obese study participants (data adapted from Bales. 2012).
If you take a look at the difference between "recall" and food frequency data on the energy intake per lean body mass, the loss in LBM in the aerobics only group (already only 0.2kg and statistically non-significant) would corroborate my previous assumption that the latter, i.e. the food frequency analysis is a more reliable tool to measure total caloric intake than the memory and awareness of portion sizes and macronutrient contents of the participants. If you translate that into dietary practice, it could imply that a more general advice on the type of foods people should eat, instead of having them count calories or macronutrients would result in a better compliance to dietary prescriptions - i.e. "eat fish once a week" instead of "get X amount of omega-3 and Y amount of taurine and ..."

Patience and consistency, not dieting and extreme exercise build better bodies

The data in figure 2 does yet also show that prescriptions like that may yet not even be necessary, for formerly sedentary people to improve their body composition. After all, none of the subjects indulged in the predicted post-exercise binges (or it did not hurt them ;-) and gained body fat instead of leaning out. Moreover, and this is a commonly overlooked, yet potentially even more important argument for working out, the subjects in the resistance training only and the combination group gained 1.0 kg (p = 0.042) and 0.6 kg (p = 0.097) of lean body mass, or as Carl, would say "metabolic currency", over the 8 months study period - and that despite likewise reduced energy intakes.

Combined with the statistically significant fat loss of -2.3kg (p < 0.001; equals -1.6% body fat). The results of the study at hand thus indicate that the adherence to a combined exercise regimen consisting of an aerobic exercise program of choice (calorically equivalent to ~12 miles/wk at 65-80% VO2 peak) and a progressive full body resistance training performed three times a week, alone will elicit long-term beneficial effects on body composition, in the absence of prescribed caloric restrictions.

Good exercise, bad exercise? 

By no means, does any type of additional exercise (again, in the absence of caloric or macronutrient restrictions) "just make you hungry"! It does rather appear that it helps to rebalance our natural ability to regulate energy intake - maybe partially due to an increased availability / accessibility of existing body fat stores due to exercise induced increases in mitochondrial fatty acid oxidation capacity and insulin sensitivity. While the "eat less and exercise more" prescription will thus still fail you, the results of the STRRIDE AT/RT Study clearly suggest that the equation "incorporate a reasonable amount of exercise into your live to rebalance your system" could hold the key to long-term successful body-recomposition (not just weight loss) in normal and overweight subjects. Whether it will suffice to help the biggest of the losers lose weight, is not only questionable, it may also simply take too long to get them back to a non-life-threatening bodyfat level by "just" having them work out (that being said, many morbidly obese patients cannot even exercise).

Image 2: The transformation Adelfo made from October 2011 to March 2012 is a testimony to the value of modest dietary restrictions and consistent and dedicated efforts in the gym.
For those of you who have already found their way, to physical culture, on the other hand, the results of the study are not just a confirmation that you are on the right track, they also confirm what you may have observed in the pictures of Adelfo Cerame's contest prep. With a nutrient dense diet, clever macronutrient modulation (no ketogenic dieting!) and lot's of hard, but not excessive work in the gym, a slight reduction in total calorie intake will burn fat not muscle. And when it is combined with appropriate refeeds and the strategic use of supplements, it appears reasonable to assume that even concomitant increases in lean body mass can be possible.