Friday, January 7, 2011

Protein Supplementation in Heavy Resistance Training: "A case for whey protein"

"Protein builds muscle!" < this is a sentence you will read pretty often in the advertisements - sorry, I meant "scientific explanations" supplement producers print onto their product labels to make you buy their newest "invention". In the end, however, it mostly comes down to a blend of different forms of whey protein with added vitamins minerals and digestive enzymes. But do you really need all that? Do you even need whey?
Table 1: Approximate Essential Amino Acid Profile of Various Protein Sources
A group of scientists from Finland (Hulmi. 2010) would probably say "YES!". In a very recent review they come to conclusions which sound pretty similar to what you can read all over the web:
Most, but not all studies have shown that supplementation of whey alone or with carbohydrates immediately after and possibly before and during resistance exercise can enhance the muscle hypertrophy response to resistance training in healthy adults. Such a response seems to at least be the case when comparing the effects of whey versus a non-energetic, or carbohydrate or soy protein alternative. Some studies also suggest that whey may enhance recovery from heavy exercise and possibly decrease muscle damage and soreness. This could, over time, enhance training adaptations by way of increasing training volume or reducing the potential for over-reaching/over-training.
There is another point, where Hulmi et al. reasoning is pretty much in line with main-stream "bro-science" and this is the extraordinary role of leucine in terms of muscle protein synthesis and hypertrophy:
[Leucine] is probable that the most important component in whey, for increasing protein synthesis and skeletal muscle size, is its high concentration of the BCAA, leucine (see
Table 1). Leucine, acting as a signaling molecule in the mTOR cascade, has been shown to be a critical amino acid for increasing skeletal muscle protein synthesis, both in vitro and in vivo in humans and rats. Leucine may also be involved in suppressing muscle protein degradation.
Their perspective is yet a little more differentiated:
However, if recent data involving rodents can be duplicated in humans, leucine concentrations from whey may only affect peak activation of skeletal MPS but not the duration of MPS or duration of mTOR signaling. Similarly, despite the positive effects of leucine per se, it likely is not the sole factor responsible for whey-induced adaptations to resistance training. For example, adding leucine to intact protein has been shown to offer little, if any, effect on protein synthesis and protein balance when consumed after resistance exercise.
Bottom line: If you go for muscle, go for whey and get drag yourself to the gym ;-)