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Ursprungligen postat av MUGEN
Grub >> du vet inte hur det är med omvandlingen av protein till glukos om man säg; enbart tar en proteinshake efter ett hårt träningspass. borde inte en stor del protein som kunde användas i eventuell proteinsyntes gå till blodsockertillverkning?
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Det gör det alltid. Det är bara dom essentiella aminosyrorna som används i proteinsyntesen. Dom icke-essentiella behövs inte i det syftet, och proteinsyntesen stimuleras till fullo av enbart tillförsel av EAA efter träning, utan kolhydrat. Kolhydrat stimulerar också proteinsyntesen, men högst marginellt i jämförelse med EAA.
Tar man båda tillsammans får man också både effekten av aminosyrorna och kolhydraterna, dvs den lilla marginella förbättringen som kolhydrat ger, men det är ingen 1+1=3 effekt, så man klarar sig utan, även om total kolhydratfrånvaro inte är att rekommendera. Insulinpåverkan är nödvändig, men den påverkan som krävs för maximal anabol stimulans är minimal, dvs knappt över fastenivåer, vilket även enbart aminosyror stimulerar.
"These findings indicate that the combined effect on net muscle protein synthesis of carbohydrate and amino acids given together after resistance exercise is roughly equivalent to the sum of the independent effects of either given alone. The individual effects of carbohydrate and amino acids are likely dependent on the amount of each that is ingested. Further, prior intake of amino acids and carbohydrate does not diminish the metabolic response to a second comparable dose ingested 1h later."
Med Sci Sports Exerc. 2003 Mar;35(3):449-55. Independent and combined effects of amino acids and glucose after resistance exercise.
"Ingestion of carbohydrate alone after
resistance exercise causes marginal
improvements in overall protein synthesis
while maintaining a negative net protein
balance. No studies have found
carbohydrate to be detrimental and it may
be useful to enhance palatability; however
the additional caloric burden may not be
desired.
A small dose of essential amino acids
after resistance exercise has been found to
stimulate protein synthesis to a similar
degree when compared to studies that
used much larger doses of both amino
acids (EAA, NEAA, or both) or that were
combined with carbohydrate.
Ingestion of amino acids after resistance
exercise has been shown at many different
time points in several studies to stimulate
increases in muscle protein synthesis,
cause minimal changes in protein
breakdown and increase overall protein
balance. It has not been conclusively
determined what time point is optimal.
Similar changes have been found for
studies that have administered amino
acids alone or with carbohydrate
immediately upon completion of an acute
exercise bout, 1 h after completion, 2 h
after completion and 3 h after completion.
Interestingly, ingesting nutrients before
the exercise bout may have the most
benefit of all the time points.
An optimal dosage in which to ingest
amino acids at this time does not exist."
Nutrient Administration and Resistance Training,
Journal of the International Society of Sports Nutrition. 2(1):50-67, 2005.