Abstract
Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P =0.001). MPS was increased above FAST at 1-3 h post-exercise in both FED (P < 0.001) and EX-FED (P < 0.001) conditions with no treatment effect. At 3-5 h, only WHEY remained significantly elevated above FAST in EX-FED (WHEY 184%vs. LEU 55% and EAA-LEU 35%; P= 0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2751-2765 |
| Number of pages | 15 |
| Journal | Journal of Physiology |
| Volume | 590 |
| Issue number | 11 |
| DOIs | |
| State | Published - Jun 2012 |
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ASJC Scopus subject areas
- Physiology
Cite this
Supplementation of a suboptimal protein dose with leucine or essential amino acids : Effects on myofibrillar protein synthesis at rest and following resistance exercise in men. / Churchward-Venne, Tyler A.; Burd, Nicholas A.; Mitchell, Cameron J.; West, Daniel W D; Philp, Andrew; Marcotte, George R.; Baker, Steven K.; Baar, Keith; Phillips, Stuart M.
In: Journal of Physiology, Vol. 590, No. 11, 06.2012, p. 2751-2765.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Supplementation of a suboptimal protein dose with leucine or essential amino acids
T2 - Effects on myofibrillar protein synthesis at rest and following resistance exercise in men
AU - Churchward-Venne, Tyler A.
AU - Burd, Nicholas A.
AU - Mitchell, Cameron J.
AU - West, Daniel W D
AU - Philp, Andrew
AU - Marcotte, George R.
AU - Baker, Steven K.
AU - Baar, Keith
AU - Phillips, Stuart M.
PY - 2012/6
Y1 - 2012/6
N2 - Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P =0.001). MPS was increased above FAST at 1-3 h post-exercise in both FED (P < 0.001) and EX-FED (P < 0.001) conditions with no treatment effect. At 3-5 h, only WHEY remained significantly elevated above FAST in EX-FED (WHEY 184%vs. LEU 55% and EAA-LEU 35%; P= 0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion.
AB - Leucine is a nutrient regulator of muscle protein synthesis by activating mTOR and possibly other proteins in this pathway. The purpose of this study was to examine the role of leucine in the regulation of human myofibrillar protein synthesis (MPS). Twenty-four males completed an acute bout of unilateral resistance exercise prior to consuming either: a dose (25 g) of whey protein (WHEY); 6.25 g whey protein with total leucine equivalent to WHEY (LEU); or 6.25 g whey protein with total essential amino acids (EAAs) equivalent to WHEY for all EAAs except leucine (EAA-LEU). Measures of MPS, signalling through mTOR, and amino acid transporter (AAT) mRNA abundance were made while fasted (FAST), and following feeding under rested (FED) and post-exercise (EX-FED) conditions. Leucinaemia was equivalent between WHEY and LEU and elevated compared to EAA-LEU (P =0.001). MPS was increased above FAST at 1-3 h post-exercise in both FED (P < 0.001) and EX-FED (P < 0.001) conditions with no treatment effect. At 3-5 h, only WHEY remained significantly elevated above FAST in EX-FED (WHEY 184%vs. LEU 55% and EAA-LEU 35%; P= 0.036). AAT mRNA abundance was increased above FAST after feeding and exercise with no effect of leucinaemia. In summary, a low dose of whey protein supplemented with leucine or all other essential amino acids was as effective as a complete protein (WHEY) in stimulating postprandial MPS; however only WHEY was able to sustain increased rates of MPS post-exercise and may therefore be most suited to increase exercise-induced muscle protein accretion.
UR - http://www.scopus.com/inward/record.url?scp=84861707373&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84861707373&partnerID=8YFLogxK
U2 - 10.1113/jphysiol.2012.228833
DO - 10.1113/jphysiol.2012.228833
M3 - Article
C2 - 22451437
AN - SCOPUS:84861707373
VL - 590
SP - 2751
EP - 2765
JO - Journal of Physiology
JF - Journal of Physiology
SN - 0022-3751
IS - 11
ER -