Thursday, January 10, 2013

Shed 11% of Your Total Fat Mass in 3 Weeks: Altitude Training Melts Fat & Builds Muscle in Elite Swimmers

Don't tell me you don't have one of these masks at home - I mean how can you expect to have 6pack abs, then  ;-)
Isn't it remarkable? It's Thursday again! Unfortunately for you (and in a way for me, because this means I got more to do) Adelfo is still for cramming for his exams so no update from "Your's Truly" this week, but a regular SuppVersity from my side. Before I get to the topic at hand and tell you what the training mask on the right is all about, let me briefly give you the usual sneak peak on today's Science Round-Up on the Super Human Radio Network. The show airs as usual at 1PM EST (click here to listen to the live stream) and will (probably) cover the following topics:
  • Resistance training, weight loss and PPAR
  • Concomitant training for endurance athletes
  • Tomato juice the ideal peri-workout drink
  • Vitamin B12 deficiency and vegetarianism / veganism
  • Protect your testes against lead & aluminum
If we got enough time, I will also talk about another thing, namely about this article, here. An article, by the way, which is about training for fat loss, and still not another post about HIIT. It doesn't include an overcomplicated workout plan with a fancy name, or an offer to buy a shiny workout DVD, it's just the summary of a paper that's about to be published in the Chinese Journal of Physiology (Chia. 2013). A study, to be precise, in the course of which the scientists from universities, colleges and research institutes in Singapore, Taipei, Taichung and *surprise* Williamsburg observed not just a statistically significant loss of body fat (-11.4% of total fat), but also a small but non-negligible increase in lean mass (+1.5%) in already highly trained young athletes within no more than three weeks (the data was measured by DXA, so you can be pretty sure that this was accurate).

Now I got your attention, right?

The subjects were a group of 18 male highly trained young swimmers (age: 14.9 ± 0.4 years, BMI: 20.8 ± 0.4 kg/m²) who regularly accomplished a total training distance of 12.3 km/day (think of the Chinese girl at the Olympics  in London, last year ;-). While 8 of them remained within their regular training environment in Singapore, the 10 subjects who had been randomized to the active group were transfered to Kunming. Contrary to Singapore, of which all of you probably know that it's a metropolis at sea level, Kunming is located at an altitude of 2,300m and thus an ideal and in fact highly frequented high altitude training camp.

Figure 1: Changes in BMI, lean and fat mass in the two study groups (Chia. 2013)
You will probably all have heard about the benefits of "living low, training high", which are supported by countless of  scientific studies and the practical experience of thousands of athletes. The lower oxygen content of the air you breath at high altitudes induces a state of intermediate hypoxia, which will enforce a whole host of metabolic adaptations that are necessary to accommodate for the lower oxygen availability and will eventually make the training more productive. The real pay-day, on the other hand, approaches, when you go back to the "low level", where you usually train (and mostly compete) and have "more than enough air" to outperform your competition on the track, in the pool or wherever else you may be running, swimming, cycling etc.

Now, all that is actually not new and wouldn't be SuppVersity news-worthy, if the Chinese and US researchers had not observed a profound and rapid (3 weeks) reduction in body fat levels in the subjects who trained in the high altitude training camp in Kunming (it should be mentioned that in animal studies similar effects have already been observed; Chen. 2010). As the data in figure 1 goes to show you, these changes were not just statistically significant (even the increase in lean mass was), but also much more pronounced than the fat loss effects of the epigallocatechin gallate (EGCG), capsaicins, piperine & carnitine stack that was in the news yesterday (cf. "EGCG, Capsaicin, Pipreine & Carnitine: Rather a Health Than a Fat Loss Stack?") -- and that despite the fact that the subjects already had a comparably low body fat level to begin with and did not restrict their total energy intake or make any other changes to their dietary or traning regimen.

"So what's that? Dark magic?"

To further elucidate the underlying mechanisms, by which the altitude training induced hypoxia  (shortage of oxygen supply) triggered this body recomposition effect (in fact, all ten swimmers demonstrated reciprocal decreases in fat mass and increases in lean mass after the 3-week altitude exposure), Chia et al. conducted a second experiment in the course of which the
"effects of hypoxia (at 16% oxygen) on blood distribution to the skeletal muscle were assessed under glucose-ingested condition (i.e. insulin-stimulated condition) after training at sea level. Skeletal muscle blood distributions were measured using near infrared spectroscopy (NIRS) to detect changes in hemoglobin concentrations under hypoxic (16% oxygen) and normoxic conditions for 90 min after oral glucose ingestion." (Chia. 2013)
Aside from the expected change in oxygen saturation and more constant hemoglobin levels during the hypoxia condition, the scientists also observed an increase in lactate production and a decreased glucose clearance from the blood, which was compensated by an increased insulin response.
Figure 2: Low frequency to high frequency ratio as a measure of sympathetic activity (left) and glucose and insulin response (right) in the follow up experiment at sea level during normal (normoxia) and low oxygen (hypoxia) conditions (Chia. 2013)
As far as the fatloss effects are concerned, the changes in autonomic nervous activity during hypoxia recovery (figure 2 right) are yet probably of greater significance. With a steady increase in the low frequency to high frequency ratio.

On the other hand, you could probably also make a point that the decreased glucose uptake in the follow-up study must have caused a shift towards fatty acid oxidation during the workout. Aside from the PGC1a and AMPK activity  Chen et al. obversed in the aforementioned rodent study (Chen. 2010), another, or rather an additional mechanism, which may explain the profound body recompositioning effects, could be mediated by a hypoxia induced increase in PDK-4 and a subsequent decrease in PDC mediated feeding of the TCA cycle with pyruvate (cf. Kelly. 2008). In order to get enough energy, the mitochondria would consequently have to ramp up their fatty acid uptake and beta-oxidation, which would require a greater release of fatty acids from the storage tissue. The latter shouldn't be a problem with the increase in autonomic nervous system activity (by the way something classic stimulant based fat burners do as well). In this context, it would have been interesting to see whether there was a major difference in the respiratory exchange ratio (RER). With the latter being an indicator of the ratio of carbs vs. fats being used as fuel, this could help clarify, whether my hypothesis is correct or not.

Looking for a less martial way to support your dietary efforts by a certain exercise regimen? Check out the HRC protocol for a "Fast Paced High-Resistant Explosive Circuit Training Burns More Fat and Builds More Muscle Than Classical Weight Training" (read more)
Bottom line: It's really intriguing to see new how an old dog, such as training at higher altitudes / in hypoxia does not even need to learn new tricks - often, all we have to do is look closely, to realize that there are beneficial "side effects" we have previously neglected.

That said, I know that your next question is, whether this does have any implications for your training? Well, as of now, probably not. It would however be interesting to see if non-altitude induced hypoxia could have similar beneficial effects. I know that the second experiment in the study at hand would suggest it does, but Ii probably don't have to tell you that it is one thing to have a reduced oxygen supply for a couple of minutes vs. 24/7, as it is the case in a high altitude training camp.


References:
  • Chen CY, Tsai YL, Kao CL, Lee SD, Wu MC, Mallikarjuna K, Liao YH, Ivy JL, Kuo
    CH. Effect of mild intermittent hypoxia on glucose tolerance, muscle morphology
    and AMPK-PGC-1alpha signaling. Chin J Physiol. 2010 Feb 28;53(1):62-71. 
  • Chia M, Liao CA, Huang CY, Lee WC, Hou CW, Yu SH, Harris MB, Hsu TS, Lee SD, Kuo CH. Reducing Body Fat with Altitude Hypoxia Training in Swimmers: Role of Blood Perfusion to Skeletal Muscles. Chinese Journal of Physiology. 2013 [Epub ahead of print]
  • Kelly DP. Hypoxic reprogramming. Nat Genet. 2008 Feb;40(2):132-4.