Acid Trip Fact vs. Fiction About Amino Acids

MYTH: To get huge, bodybuilders should eat as much as possible...all day long. Bodybuilders should even stick an IV drip of amino acids into their arms and sleep with a continuous supply of them pulsing through their body to maintain continuous protein synthesis!

TRUTH: Science actually supports just the opposite. Continuous infusion of amino acids via IVs has been shown to be less effective at stimulating protein synthesis than intermittent feeding with protein. The boosting of muscle protein synthesis by a meal or amino acids is rapid and is sustained for at least two hours but then declines toward normal levels, which occurs in conjunction with the changes in circulating insulin and aminos.The signaling protein mTOR, which catalyzes muscle protein synthesis, is stimulated by both insulin and amino acids, especially the amino leucine. Researchers from McMaster University in Hamilton, Ontario, reported recently that men who consumed whey protein after exercise, either by consuming the entire drink rapidly or consuming it spaced every 20 minutes over a 200-minute feeding period, had dramatically different results despite consuming the same amount. Muscle biopsies taken from the subjects found that muscle protein synthesis was elevated to a greater extent after rapidly consuming a large single dose of whey protein than after consuming it in smaller portions over a longer period. There were greater changes in anabolic signaling pathways for muscle hypertrophy (growth) after rapid rather than slow consumption.

For years in bodybuilding circles, you heard of bodybuilders who would have an IV drip of amino acids stuck into their arms before they went to sleep so they could maintain a positive protein synthesis rate while not eating. In a recent study in the Journal of Nutrition, research- ers examined how taking an intravenous tube and feeding with continuous versus bursts of aminos would alter protein ki- netics. According to Broscience, the continuous IV feeding of amino acids should be the best for increasing protein synthesis. Wrong! The researchers that although both continuous and intermittent feeding stimulated muscle protein synthesis, the greatest increase in muscle protein synthesis occurred in the intermittently fed group. This upsurge in muscle protein synthesis was associated with more rapid changes in circulating amino acids and insulin that activate the protein signaling pathways. So it seems that there may be some truth to getting up in the middle of the night and eating some food or throw- ing down a protein shake. One thing is certain—you don’t have to stick an IV in your arm at night. Leave that for the Broscientists!