TY - JOUR
T1 - No effect of creatine supplementation on human myofibrillar and sarcoplasmic protein synthesis after resistance exercise
AU - Louis, Magali
AU - Poortmans, Jacques R.
AU - Francaux, Marc
AU - Berré, Jacques
AU - Boisseau, Nathalie
AU - Brassine, Eric
AU - Cuthbertson, Daniel J.R.
AU - Smith, Kenneth
AU - Babraj, John A.
AU - Waddell, Tom
AU - Rennie, Michael J.
PY - 2003/11
Y1 - 2003/11
N2 - Muscle hypertrophy during resistance training is reportedly increased by creatine supplementation. Having previously failed to find an anabolic effect on muscle protein turnover at rest, either fed or fasted, we have now examined the possibility of a stimulatory effect of creatine in conjunction with acute resistance exercise. Seven healthy men (body mass index, 23 ±2 kg/m2, 21 ± 1 yr, means ± SE) performed 20 x 10 repetitions of leg extension-flexion at 75% one-repetition maximum in one leg, on two occasions, 4 wk apart, before and after ingesting 21 g/day creatine for 5 days. The subjects ate ∼21 g maltodextrin + 6 g protein/h for 3 h postexercise. We measured incorporation of [1-13C]leucine into quadriceps muscle proteins in the rested and exercised legs. Leg protein breakdown (as dilution of [2H5]phenylalanine) was also assessed in the exercised and rested leg postexercise. Creatine supplementation increased muscle total creatine by approximately 21% (P < 0.01). Exercise increased the synthetic rates of myofibrillar and sarcoplasmic proteins by two- to threefold (P < 0.05), and leg phenylalanine balance became more positive, but creatine was without any anabolic effect.
AB - Muscle hypertrophy during resistance training is reportedly increased by creatine supplementation. Having previously failed to find an anabolic effect on muscle protein turnover at rest, either fed or fasted, we have now examined the possibility of a stimulatory effect of creatine in conjunction with acute resistance exercise. Seven healthy men (body mass index, 23 ±2 kg/m2, 21 ± 1 yr, means ± SE) performed 20 x 10 repetitions of leg extension-flexion at 75% one-repetition maximum in one leg, on two occasions, 4 wk apart, before and after ingesting 21 g/day creatine for 5 days. The subjects ate ∼21 g maltodextrin + 6 g protein/h for 3 h postexercise. We measured incorporation of [1-13C]leucine into quadriceps muscle proteins in the rested and exercised legs. Leg protein breakdown (as dilution of [2H5]phenylalanine) was also assessed in the exercised and rested leg postexercise. Creatine supplementation increased muscle total creatine by approximately 21% (P < 0.01). Exercise increased the synthetic rates of myofibrillar and sarcoplasmic proteins by two- to threefold (P < 0.05), and leg phenylalanine balance became more positive, but creatine was without any anabolic effect.
U2 - 10.1152/ajpendo.00195.2003
DO - 10.1152/ajpendo.00195.2003
M3 - Article
VL - 285
SP - E1089-E1094
JO - AJP Endocrinology & Metabolism
JF - AJP Endocrinology & Metabolism
IS - 5
ER -