I am not sure where the 1 hr. window came from, but I do believe it optimal to get some fast acting protein with equally fast carbs soon after a workout. In fact, I believe another one about 40 minutes later may be just as potent.
While it is true that it is what you do over weeks, months, years that add up to gains, you may be able to expediate the process with optimally timed protein/amino acid shakes. In fact, I found this study that may even relate this more.....
this study seems to indicate that amino acids are uptaken better. Post workout is probably an even more ideal time.
Recently, researchers from the University of Texas examined the effects of ingesting a carbohydrate (30g) and amino acid supplement (15g of essential amino acids) (CAA) or a meal on protein synthesis. Thirteen men ages 28 to 48 years of age where randomly into two tow treatment groups: 1) CAA= 36+OR- 10 years and 2)Control 38 + or -8 year. The CAA and meal was designed to be similar in amino acid content and were administered perodically throughout the day blood and muscle tissue was samples were collected in order to assess anabolism. The inclusion of a CAA supplement into a normal diet resulted in a greater anabolic stimulus as the meal treatment indicated by the 25% increase in protein synthesis rate. Additionally, the consumption of only meals throughout the 16 hour study period resulted in a negative net protein balance, while adding frequent CAA supplements resulted in a positive balance. The researchers suggested that the CAA supplement was more effective in maximizing protein synthesis rates as result of the speed with which the supplement is digested and taken up into the system. Based upon these findings it may be recommended for athletes consume some sort of CAA supplement throughout the day in order to maximize the muscular adaptations to their training regimes and maintain a positive protein balance.
This study on the surface seems to favor amino acids over whole food, but this is just the abstract. I would venture to interpret it more as an amino acid supplement taken with your meals would be more anabolic. Makes comon sense....add 2 protein shakes per day for instance on top of your meals, and you are typically adding at least 40 gr. of protein assuming one scoop per shake. This in fact would seem to have to sway the nitrogen balance more positive.