
Originally Posted by
MickeyKnox
Alan Aragon:
"The post-exercise "anabolic window" is a highly misused & abused concept. Preworkout nutrition all but cancels the urgency, unless you're an endurance athlete with multiple glycogen-depleting events in a single day. Getting down to brass tacks, a relatively recent study (Power et al. 2009) showed that a 45g dose of whey protein isolate takes appx. 50 minutes to cause blood AA levels to peak. Resulting insulin levels, which peaked at 40 minutes after ingestion, remained at elevations known to max out the inhibition of muscle protein breakdown (15-30 mU/L) for 120 minutes after ingestion. This dose takes 3 hours for insulin & AA levels to return to baseline from the point of ingestion. The inclusion of carbs to this dose would cause AA & insulin levels to peak higher & stay elevated above baseline even longer.
So much for the anabolic peephole & the urgency to down AAs during your weight training workout; they are already seeping into circulation (& will continue to do so after your training bout is done). Even in the event that a preworkout meal is skipped, the anabolic effect of the post workout meal is increased as a supercompensatory response (Deldicque et al, 2010). Moving on, another recent study (Staples et al, 2010) found that a substantial dose of carbohydrate (50g maltodextrin) added to 25g whey protein was unable to further increase post-exercise net muscle protein balance compared to the protein dose without carbs. Again, this is not to say that adding carbs at this point is counterproductive, but it certainly doesn't support the idea that you must get your lightning-fast post-exercise carb orgy for optimal results.
Something that people don't realize is that there's no "magic anabolic window" that's open for a short period of time near the workout & then rapidly disappears. As a result of a single training bout, the receptivity of muscle to protein dosing can persist for at least 24 hours." (Burd et al, 2011).