Ikke tenk så mye på dette. Som Stallion nevner så er den rent praktiske forskjellen ganske så ubetydelig. Selv om hurtig protein som myse tas opp med kanskje litt over 10 g pr time, og langsomme som kasein med <6 g, så er det dermed ikke så enkelt at man klarer å nyttigjøre seg av mer av proteinene fra myse. Rask protein fører til at man får kjapt får mer aminosyrer ut i blodet, men dette fører i sin tur bare til økt proteinnedbrytning (1), så "vinninga går opp i spinninga" på en måte. Merk og at protein som myse kun er kjapt hvis du bare får i deg myse. Sammen med annen mat blir den mer langsom.
Utover rundt trening, da rask protein trolig kan være å foretrekke (selv om man ikke sett så store forskjeller) så er langsomme proteiner (m.a.o. "vanlig" mat) å foretrekke for yngre individer, men hos eldre kan "pulse feeding" med rask protein (f.eks. gjennom hyppige mysedrinker) være bedre (2).
1. "Absorption rates of amino acids from the gut can vary from 1.4 g/h for raw egg
white to 8 to 10 g/h for whey protein isolate. Slowly absorbed amino acids such
as casein (~ 6 g/h) and repeated small doses of whey protein (2.9 g per 20 min,
totaling ~ 7 g/h) promote leucine balance, a marker of protein balance, superior to
that of a single dose of 30 g of whey protein or free amino acids which are both
rapidly absorbed (8 to 10 g/h), and enhance amino acid oxidation. This gives us
an initial understanding that although higher protein intakes are physiologically
possible, and tolerable by the human body, they may not be functionally optimal
in terms of building and preserving body protein. The general, although incorrect
consensus among athletes and bodybuilders, is that rapid protein absorption corresponds
to greater muscle building."
International Journal of Sport Nutrition and Exercise Metabolism, 2006, 16, 129-152
2 "In young men ingesting protein meals, slowly digested proteins (caseins: CAS) induce a higher protein gain than those that are rapidly digested (whey proteins: WP). Our aim was to assess whether or not this is true in elderly men receiving mixed meals. The effects of meals containing either CAS or two different amounts of WP (WP-iN: isonitrogenous with CAS, or WP-iL: providing the same amount of leucine as CAS) on protein metabolism (assessed by combining oral and intravenous leucine tracers) were compared in nine healthy, elderly (mean +/- S.E.M. age 72 +/- 1 years) and six young men (24 +/- 1 years).
In conclusion, during aging, protein gain was greater with WP (rapidly digested protein), and lower with CAS (slowly digested protein). This suggests that a 'fast' protein might be more beneficial than a 'slow' one to limit protein losses during aging."
J Physiol. 2003 Jun 1;549(Pt 2):635-44. Epub 2003 Mar 28. The rate of protein digestion affects protein gain differently during aging in humans.
