1) Nutrient availability
2) Physical activity
If we look firstly at nutrient availability we see that protein stimulates muscle protein synthesis.
The time course goes something like this:
– Consumption of >25g protein
– After ~30mins rapid increase in muscle protein synthesis
– This peaks at ~1.5 hours after protein ingestion
– Returns to baseline by 2 hours
Note that this happens even in the presence of essential amino acids (broken down protein). So it is not a lack of nutrients that limits muscle protein synthesis.
This adds even more weight to the lack of rationale behind taking BCAAs. Not only do we know that we need all essential amino acids – not just branched chained. But even in the presence of ample nutrient supply we can’t sustain muscle protein synthesis. So if you think you are sparing muscle mass by sipping BCAAs all day .. your money is better spent on the new gym shark track suit..
Interestingly this observation does support the suggestion that eating every 2 hours is a good idea. This recommendation is fairly common amongst body builders. It is often supported by the belief that frequent meals will result in a higher metabolism or that you must eat regularly to keep your metabolism going and aid fat loss. This is not true. How you wish to split your calorie intake over the day will not impact weight loss given calorie intake remains the same.
However, where the recommendation of eating every 2 hours may have *some* support is in the pursuit of optimal muscle mass. In theory you could stimulate muscle protein synthesis via protein ingestion every 2-3 hours.
Whether this feeding regime would make real world muscle mass improvements over a less frequent feeding pattern or if this advantage is of a magnitude that merits the effort and cost of eating every 2-3hours is debatable.
If you’re a competitive body builder why not go all in and get any potential edge you can. If you want to add some muscle but still care about life balance. There are much more important factors to get right first.. don’t worry about protein timing if you’re not training consistently, sleeping enough and getting in enough nutrients in the first place.
PS this probably bares very little relevance to most of you but I am a geek and I thought some of you might find this interesting even if not applicable.