1Evans, WJ (1995) What is sarcopenia? J Gerontol A Biol Sci Med Sci 50, 5–8.
2Short, KR, Vittone, JL, Bigelow, ML, Proctor, DN & Nair, KS (2004) Age and aerobic exercise training effects on whole body and muscle protein metabolism. Am J Physiol Endocrinol Metab 286, E92–E101.
3Wolfe, RR (2002) Regulation of muscle protein by amino acids. J Nutr 132, 3219S–3224S.
4Volpi, E, Mittendorfer, B, Rasmussen, BB & Wolfe, RR (2000) The response of muscle protein anabolism to combined hyperaminoacidemia and glucose-induced hyperinsulinemia is impaired in the elderly. J Clin Endocrinol Metab 85, 4481–4490.
5Guillet, C, Prod'homme, M, Balage, M, Gachon, P, Giraudet, C, Morin, L, Grizard, J & Boirie, Y (2004) Impaired anabolic response of muscle protein synthesis is associated with S6K1 dysregulation in elderly humans. FASEB J 18, 1586–1587.
6Cuthbertson, D, Smith, K, Babraj, J, Leese, G, Waddell, T, Atherton, P, Wackerhage, H, Taylor, PM & Rennie, MJ (2005) Anabolic signaling deficits underlie amino acid resistance of wasting, aging muscle. FASEB J 19, 422–424.
7Phillips, SM, Tipton, KD, Aarsland, A, Wolf, SE & Wolfe, RR (1997) Mixed muscle protein synthesis and breakdown after resistance exercise in humans. Am J Physiol 273, (1 Pt 1), E99–E107.
8Rennie, MJ & Tipton, KD (2000) Protein and amino acid metabolism during and after exercise and the effects of nutrition. Annu Rev Nutr 20, 457–483.
9Koopman, R, Verdijk, LB, Manders, RJF, Gijsen, AP, Gorselink, M, Pijpers, E, Wagenmakers, AJM & van Loon, LJC (2006) Co-ingestion of protein and leucine stimulates muscle protein synthesis rates to the same extent in young and elderly lean men. Am J Clin Nutr 84, 623–632.
10Koopman, R, Wagenmakers, AJ, Manders, RJ, Zorenc, AH, Senden, JM, Gorselink, M, Keizer, HA & van Loon, LJ (2005) Combined ingestion of protein and free leucine with carbohydrate increases postexercise muscle protein synthesis in vivo in male subjects. Am J Physiol Endocrinol Metab 288, E645–E653.
11Anthony, JC, Anthony, TG & Layman, DK (1999) Leucine supplementation enhances skeletal muscle recovery in rats following exercise. J Nutr 129, 1102–1106.
12Crozier, SJ, Kimball, SR, Emmert, SW, Anthony, JC & Jefferson, LS (2005) Oral leucine administration stimulates protein synthesis in rat skeletal muscle. J Nutr 135, 376–382.
13Dardevet, D, Sornet, C, Bayle, G, Prugnaud, J, Pouyet, C & Grizard, J (2002) Postprandial stimulation of muscle protein synthesis in old rats can be restored by a leucine-supplemented meal. J Nutr 132, 95–100.
14Rieu, I, Sornet, C, Bayle, G, Prugnaud, J, Pouyet, C, Balage, M, Papet, I, Grizard, J & Dardevet, D (2003) Leucine-supplemented meal feeding for ten days beneficially affects postprandial muscle protein synthesis in old rats. J Nutr 133, 1198–1205.
15Anthony, JC, Reiter, AK, Anthony, TG, Crozier, SJ, Lang, CH, MacLean, DA, Kimball, SR & Jefferson, LS (2002) Orally administered leucine enhances protein synthesis in skeletal muscle of diabetic rats in the absence of increases in 4E-BP1 or S6K1 phosphorylation. Diabetes 51, 928–936.
16Kimball, SR, Farrell, PA & Jefferson, LS (2002) Invited Review: role of insulin in translational control of protein synthesis in skeletal muscle by amino acids or exercise. J Appl Physiol 93, 1168–1180.
17Nair, KS, Schwartz, RG & Welle, S (1992) Leucine as a regulator of whole body and skeletal muscle protein metabolism in humans. Am J Physiol 263, (5 Pt 1), E928–E934.
18Rieu, I, Balage, M, Sornet, C, Giraudet, C, Pujos, E, Grizard, J, Mosoni, L & Dardevet, D (2006) Leucine supplementation improves muscle protein synthesis in elderly men independently of hyperaminoacidaemia. J Physiol, 575, , 305–315.
19Katsanos, CS, Kobayashi, H, Sheffield-Moore, M, Aarsland, A & Wolfe, RR (2006) A high proportion of leucine is required for optimal stimulation of the rate of muscle protein synthesis by essential amino acids in the elderly. Am J Physiol Endocrinol Metab 291, E381–387.
20Matthews, DR, Hosker, JP, Rudenski, AS, Naylor, BA, Treacher, DF & Turner, RC (1985) Homeostasis model assessment: insulin resistance and beta-cell function from fasting plasma glucose and insulin concentrations in man. Diabetologia 28, 41241–41249.
21Jones, PR & Pearson, J (1969) Anthropometric determination of leg fat and muscle plus bone volumes in young male and female adults. J Physiol 204, 63P–66P.
22Mayhew, JL, Prinster, JL, Ware, JS, Zimmer, DL, Arabas, JR & Bemben, MG (1995) Muscular endurance repetitions to predict bench press strength in men of different training levels. J Sports Med Phys Fitness 35, 108–113.
23American College of Sports Medicine Position Stand (1998) The recommended quantity and quality of exercise for developing and maintaining cardiorespiratory and muscular fitness, and flexibility in healthy adults. Med Sci Sports Exerc 30, 975–991.
24Pate, RR, Pratt, M, Blair, SN, et al. (1995) Physical activity and public health. A recommendation from the Centers for Disease Control and Prevention and the American College of Sports Medicine. JAMA 273, 402–407.
25Gunn, SM, Brooks, AG, Withers, RT, Gore, CJ, Owen, N, Booth, ML & Bauman, AE (2002) Determining energy expenditure during some household and garden tasks. Med Sci Sports Exerc 34, 895–902.
26Wagenmakers, AJ (1999) Tracers to investigate protein and amino acid metabolism in human subjects. Proc Nutr Soc 58, 987–1000.
27Fekkes, D, van Dalen, A, Edelman, M & Voskuilen, A (1995) Validation of the determination of amino acids in plasma by high-performance liquid chromatography using automated pre-column derivatization with o-phthaldialdehyde. J Chromatogr B Biomed Appl 669, 177–186.
28Wolfe, RR (1992) Radioactive and Stable Isotope Tracers in Biomedicine: Principles and Practice of Kinetic Analysis. New York: Wiley-Liss.
29van Eijk, HM, Rooyakkers, DR & Deutz, NE (1993) Rapid routine determination of amino acids in plasma by high-performance liquid chromatography with a 2–3 microns Spherisorb ODS II column. J Chromatogr 620, 143–148.
30Koopman, R, Pannemans, DL, Jeukendrup, AE, Gijsen, A, Senden, JMG, Halliday, D, Saris, WHM, van Loon, LJC & Wagenmakers, AJM (2004) The combined ingestion of protein and carbohydrate improves protein balance during ultra endurance exercise. Am J Physiol Endocrinol Metab 287, E712–E720.
31Thompson, GN, Pacy, PJ, Merritt, H, Ford, GC, Read, MA, Cheng, KN & Halliday, D (1989) Rapid measurement of whole body and forearm protein turnover using a [2H5]phenylalanine model. Am J Physiol 256, (5 Pt 1), E631–E639.
32Short, KR, Meek, SE, Moller, N, Ekberg, K & Nair, KS (1999) Whole body protein kinetics using Phe and Tyr tracers: an evaluation of the accuracy of approximated flux values. Am J Physiol 276, , E1194–E1200.
33Buse, MG & Reid, SS (1975) Leucine. A possible regulator of protein turnover in muscle. J Clin Invest 56, 1250–1261.
34Kimball, SR & Jefferson, LS (2004) Regulation of global and specific mRNA translation by oral administration of branched-chain amino acids. Biochem Biophys Res Commun 313, 423–427.
35Matthews, DE (2005) Observations of branched-chain amino acid administration in humans. J Nutr 135, Suppl., 1580S–1584S.
36Alvestrand, A, Hagenfeldt, L, Merli, M, Oureshi, A & Eriksson, LS (1990) Influence of leucine infusion on intracellular amino acids in humans. Eur J Clin Invest 20, 293–298.
37Van Hall, G, Saltin, B & Wagenmakers, AJ (1999) Muscle protein degradation and amino acid metabolism during prolonged knee-extensor exercise in humans. Clin Sci (Lond) 97, 557–567.
38Chang, TW & Goldberg, AL (1978) The origin of alanine produced in skeletal muscle. J Biol Chem 253, 3677–3684.
39Manders, RJ, Wagenmakers, AJ, Koopman, R, Zorenc, AH, Menheere, PP, Schaper, NC, Saris, WH & van Loon, LJ (2005) Co-ingestion of a protein hydrolysate and amino acid mixture with carbohydrate improves plasma glucose disposal in patients with type 2 diabetes. Am J Clin Nutr 82, 76–83.
40van Loon, LJ, Kruijshoop, M, Menheere, PP, Wagenmakers, AJ, Saris, WH & Keizer, HA (2003) Amino acid ingestion strongly enhances insulin secretion in patients with long-term type 2 diabetes. Diabetes Care 26, 625–630.
41Anthony, JC, Anthony, TG, Kimball, SR & Jefferson, LS (2001) Signaling pathways involved in translational control of protein synthesis in skeletal muscle by leucine. J Nutr 131, 856S–860S.