A popular research topic in the modern Sport Science studies has been pre- and post-training nutrition, and their effects on performance. However, more recent research hasfocused on intra-workout nutrition as well. This review will touch on all three.Before proceeding further, one must understand the concept of Net Protein Balance. NetProtein Balance (NPB) equals Muscle Protein Synthesis (MPS) minus Muscle ProteinBreakdown (MPB), or NPB = MPS - MPB. And for muscle repair to occur, NPB must bepositive, that is, MPS > MPB. And though MPS does increase with resistance training, itis not enough to be greater than MPB. NPB can only be positive when some sort ofprotein is consumed in conjunction with resistance training. Phillips et al JACN 2005.Pre-workout nutrition has been discovered to be as important, if not more, than post. Inseveral recent studies, the consumption of plain water, a carbohydrate (CHO) drink, awhole protein and CHO drink, and an Essential Amino Acid (EEA) and CHO drink wasanalyzed. The results were that with the consumption of 6g of EEA, along with 35g ofCHO, stimulated the greatest amount of net protein synthesis, and that this combination issignificantly superior to the other fluids. More importantly, however, is that NPS issuperior when this combination of EEA and CHO is consumed prior to exercise ascompare to when consumed after exercise. Tipton et al AJP 2001.For intra workout nutrition, the consumption of 6g of EEA with 35g of CHO,independent of the pre-workout meal, presents several major benefits: a greater decreasein Cortisol; the greatest effect on Insulin release post exercise; the greatest effect onTestosterone release during exercise; and the greatest decrease in Muscle ProteinBreakdown up to 48 hours post exercise. It also boosts the anabolic effect of resistancetraining to greater extent vs. CHO or EEA independently. Byrd et al 2006. Also, duringglycolysis, carbohydrate ingestion helps with the maintenance of intramuscular glycogenstores due to greater glycogen resynthesis during resistance training: muscle glycogenstores are used during repeated bouts of anaerobic activity. When a particular set isdiscontinued, the glycogen stores attempt to reload, up to the commencement of anotherbout of exercise, in which the glycogen stores are activated once again. The consumptionof 4-8g/mL of CHO provides adequate CHO for glycogen maintenance during exercisewithout gastric emptying distress.In regards to post workout, both casein and whey protein are very rich in EEAs andBCAAs. Since casein clots in the gut, it delays gastric emptying, thereby exhibiting aslower release of aminos. Whey is soluble, allowing for a faster gastric emptying, andtherefore a more rapid release of aminos. It had been thought that consuming casein withwhey post workout would delay the absorption of whey, minimizing the effectiveness ofits rapid release of aminos. However, a major find is that consuming casein and wheytogether will not negatively affect the absorption of each individually. In fact, thecombination of both, such as in milk, seems to improve their absorbability, and willactually provided protein synthesis 4-9 times better and for longer period of time postworkout than casein or whey individually. Bilsborough et al IJSNEM 2006.
At least 15g of whole protein is needed in order to get at least 6g of EAAs post workout.However, the effectiveness ceiling may be 40g.Also, though no study has definitively concluded a specific ratio of CHO and protein postworkout (2:1, 4:1, etc.), research has concluded that the aforementioned protein must beconsumed in conjunction with a CHO in a ratio greater than 1:1 in order to maximize theabsorbability of both the protein and the CHO. And, since glucose is not insulindependent post workout, a combo of CHO/PRO will also provided for greatest storage ofglycogen, as well as a greater insulin response. Ivy et al JAP 2002, Van Loon et al AJCN2000.