In the grand scheme of things, this article is nothing revolutionary – quite the opposite in fact as it may seem quite obvious. Oxygen deprivation (hypoxia) is generally bad for the whole ‘living’ concept, so you’d expect it would not be all that fantastic for muscle growth. And yet the way we train as bodybuilders and as powerlifters involves an oxygen-absent metabolic pathway called anaerobic respiration. Obviously we can’t train and live anaerobically indefinitely because we haven’t evolved that way, but for short bursts of time we can, and the eventual outcome is growth. The real interest in this article in how the cell caters for these periods of hypoxia and whether we can take advantage of it to benefit training.
Scientists have identified a gene called DNA-damage-inducible transcript 4, which is also known (and more easily remembered) as REDD1. It is REDD1’s job to suppress energy-costly metabolic processes during cellular stress in order to prevent the cell exceeding its limits. Growth and replication are considered costly when the life of the cell is at stake. It does this by inhibiting the mammalian target of rapamycin, which you may be more familiar with when I give its acronym, mTOR. If you didn’t already know, mTOR is the regulator of cell proliferation and protein synthesis. Out of interest, its not just hypoxia that activates REDD1 – glucocorticoids (such as cortisol) do also, explaining one of the (if not the) ways in which they are really not super-duper for muscle growth. The REDD1 gene excites scientists because they are looking into ways of inducing cell death in specific cells, such as tumor and cancer cells, without harming the existing healthy cells. As bodybuilders, all we want to know is how to get bigger and stronger, right? The removal of REDD1 is quite rapid once oxygen levels normalize, controlled by the ubiquitin-proteasome pathway. This allows the cell to deal with periods of stress really quite brilliantly.
And now onto some questions for which I currently have no answers; namely, is hypoxia training a bad idea or does it help prep us for the periods of low oxygen during training? The cell can deal with short periods of low oxygen very well, and we can still cause muscle growth despite it. There is equipment available to buy for this very purpose, limiting the amount of breath you can take in, not to mention the practice of some UFC athletes who tape their nostrils closed and breathe through a snorkel. And some athletes have been training at altitude for competition for decades. Is it worth it? No idea, but any feedback based on your experiences is most welcome.
Update: A new study in support of hypoxia for improving body composition.
http://www.nature.com/oby/journal/vaop/ncurrent/abs/oby2009509a.html
Source: Katiyar S, Liu E, Knutzen CA, Lang ES, Lombardo CR, Sankar S, Toth JI, Petroski MD, Ronai Z, Chiang GG. REDD1, an inhibitor of mTOR signalling, is regulated by the CUL4A-DDB1 ubiquitin ligase. EMBO Rep. 2009 Aug;10(8):866-72.
Matt Cahill has worked extensively in the nutritional supplement field, and is the former CEO of Designer Supplements. During his time in the field has researched and developed prohormones, testosterone boosters, and other related compounds, both for his own company and others. 