Proteinintag före träning och stimulerad proteinsyntes efter passet

[King Grub]

PURPOSE:

We have previously shown that the aminoacidemia caused by the consumption of a rapidly digested protein after resistance exercise enhances muscle protein synthesis (MPS) more than the amino acid (AA) profile associated with a slowly digested protein. Here, we investigated whether differential feeding patterns of a whey protein mixture commencing prior to exercise affect post-exercise intracellular signaling and muscle protein synthesis (MPS).

METHODS:

Twelve resistance-trained males performed leg resistance exercise 45 min after commencing each of three volume-matched nutrition protocols: placebo (PLAC; artificially sweetened water); BOLUS (25 g whey protein + 5 g leucine dissolved in artificially sweetened water; 1 × 500 mL); or PULSE (15 × 33 mL aliquots of BOLUS drink every 15 min).

RESULTS:

The pre-exercise rise in plasma AA concentration with PULSE was attenuated compared with BOLUS (P<0.05); this effect was reversed following exercise, with two-fold greater leucine concentrations in PULSE compared to BOLUS (P<0.05). One-hour post-exercise, phosphorylation of p70 S6K and rpS6 was increased above baseline with BOLUS and PULSE, but not PLAC (P<0.05); furthermore, PULSE > BOLUS (P<0.05). MPS throughout 5 h of recovery was higher with protein ingestion compared with PLAC (0.037 ±0.007) with no differences between BOLUS or PULSE (0.085 ±0.013 vs 0.095 ±0.010 %·h respectively, P = 0.56).

CONCLUSIONS:

Manipulation of aminoacidemia prior to resistance exercise via different patterns of intake of protein, altered plasma AA profiles and post-exercise intracellular signaling. However, there was no difference in the enhancement of the muscle protein synthetic response after exercise. Protein sources producing a slow AA release, when consumed before resistance exercise in sufficient amounts, are as effective as rapidly digested proteins in promoting post-exercise muscle protein synthesis.

Med Sci Sports Exerc. 2012 May 21. Preexercise Aminoacidemia and Muscle Protein Synthesis after Resistance Exercise.

[Eddie Vedder]

Var tvungen att kolla så det var en cross-over och det var det tack och lov. ;) Kul att det görs jämförelser på BOLUS vs. PULSE. Det har ju varit lite skralt, minst sagt, med evidensen för små intag kontra bolus även om det sistnämnda är populärt. EAA/BCAA direkt före och direkt efter blir ju en form av mellanting här, två bolusintag men med lite längre tid emellan än man hade här.

Den enda jämförelsen jag vet sedan tidigare är ju gjort på aminoacidemia direkt efter passet och den är ju med i referenslistan. Och då verkade ju BOLUS vara bättre.

Abstract
BACKGROUND:

Ingestion of whey or casein yields divergent patterns of aminoacidemia that influence whole-body and skeletal muscle myofibrillar protein synthesis (MPS) after exercise. Direct comparisons of the effects of contrasting absorption rates exhibited by these proteins are confounded by their differing amino acid contents.
OBJECTIVE:

Our objective was to determine the effect of divergent aminoacidemia by manipulating ingestion patterns of whey protein alone on MPS and anabolic signaling after resistance exercise.
DESIGN:

In separate trials, 8 healthy men consumed whey protein either as a single bolus (BOLUS; 25-g dose) or as repeated, small, "pulsed" drinks (PULSE; ten 2.5-g drinks every 20 min) to mimic a more slowly digested protein. MPS and phosphorylation of signaling proteins involved in protein synthesis were measured at rest and after resistance exercise.
RESULTS:

BOLUS increased blood essential amino acid (EAA) concentrations above those of PULSE (162% compared with 53%, P < 0.001) 60 min after exercise, whereas PULSE resulted in a smaller but sustained increase in aminoacidemia that remained elevated above BOLUS amounts later (180-220 min after exercise, P < 0.05). Despite an identical net area under the EAA curve, MPS was elevated to a greater extent after BOLUS than after PULSE early (1-3 h: 95% compared with 42%) and later (3-5 h: 193% compared with 121%) (both P < 0.05). There were greater changes in the phosphorylation of the Akt-mammalian target of rapamycin pathway after BOLUS than after PULSE.
CONCLUSIONS:

Rapid aminoacidemia in the postexercise period enhances MPS and anabolic signaling to a greater extent than an identical amount of protein fed in small pulses that mimic a more slowly digested protein. A pronounced peak aminoacidemia after exercise enhances protein synthesis.

West DW et al. Rapid aminoacidemia enhances myofibrillar protein synthesis and anabolic intramuscular signaling responses after resistance exercise. Am J Clin Nutr. 2011 Sep;94(3):795-803.