It is well understood that whey protein consumed after a weights
training session causes rapid entry of amino acids into circulation
and subsequent uptake into the muscles to promote muscle recovery and
tissue remodeling (ie. muscle growth).
One of the more commonly asked question by people in search of
improved recovery after training and heightened muscular adaptation is
'which is better: pre or post training protein?'.
To answer this question, Professor Louise Burke and her colleagues at
the AIS (and other international research institutions) gave subjects
either a placebo drink, a beverage containing 25 grams of whey protein
or 15 mini-protein sips every 15 minutes and then performed 45 minutes
of lower body resistance training.
Amino acid concentration in the blood was measured at various time
points after training, as was the amount of muscle protein synthesis.
Professor Burke and colleagues concluded that "there was no difference
in the enhancement of the muscle protein synthetic response after
exercise. Protein sources producing a slow amino acid release, when
consumed before resistance exercise in sufficient amounts, are as
effective as rapidly digested proteins in promoting postexercise
muscle protein synthesis".
So the take home message from this study (and others that have
compared pre and post training protein consumption) suggests that
personal preference should dictate whether you consume your whey
protein before or after exercise, as both approaches appear to be as
good as each other in turning on muscle protein synthesis.