Low-Dose Creatine Combined with Protein during Resistance Training in Older Men

• Autores: Darren G. Candow, John Little, Philip D. Chilibeck, Saman Abeysekara, Gordon A. Zello, Michael Kazachkov, Stephen M. Cornish, Peter H. Yu
• Localización: Medicine & Science in Sports & exercise: Official Journal of the American College of Sports Medicine, ISSN 0195-9131, Vol. 40, Nº. 9, 2008, págs. 1645-1652
• Idioma: inglés
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• Dialnet Métricas: 2 Citas
• Resumen

  • Purpose: To determine whether low-dose creatine and protein supplementation during resistance training (RT; 3 d[middle dot]wk-1; 10 wk) in older men (59-77 yr) is effective for improving strength and muscle mass without producing potentially cytotoxic metabolites (formaldehyde).

    Methods: Older men were randomized (double-blind) to receive 0.1 g[middle dot]kg-1 creatine + 0.3 g[middle dot]kg-1 protein (CP; n = 10), creatine (C; n = 13), or placebo (PLA; n = 12) on training days. Measurements before and after RT included lean tissue mass (air-displacement plethysmography), muscle thickness (ultrasound) of elbow, knee, and ankle flexors and extensors, leg and bench press strength, and urinary indicators of cytotoxicity (formaldehyde), myofibrillar protein degradation [3-methylhistidine (3-MH)],and bone resorption [cross-linked N-telopeptides of type I collagen (NTx)].

    Results: Subjects in C and CP groups combined experienced greater increases in body mass and total muscle thickness than PLA (P < 0.05). Subjects who received CP increased lean tissue mass (+5.6%) more than C (+2.2%) or PLA (+1.0%; P < 0.05) and increased bench press strength (+25%) to a greater extent than C and PLA combined (+12.5%; P < 0.05). CP and C did not differ from PLA for changes in formaldehyde production (+24% each). Subjects receiving creatine (C and CP) experienced a decrease in 3-MH by 40% compared with an increase of 29% for PLA (P < 0.05) and a reduction in NTx (-27%) versus PLA (+13%; P = 0.05).

    Conclusions: Low-dose creatine combined with protein supplementation increases lean tissue mass and results in a greater relative increase in bench press but not leg press strength. Low-dose creatine reduces muscle protein degradation and bone resorption without increasing formaldehyde production.