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Tarnopolsky et al. (1992) observed no differences in whole body protein synthesis or indexes of lean body mass in strength athletes consuming either 0.64g/lb or 1.10g/lb over a 2 week period. Protein oxidation did increase in the high protein group, indicating a nutrient overload.
Walberg et al. (1988) found that 0.73g/lb was sufficient to maintain positive nitrogen balance in cutting weightlifters over a 7 day time period.
Tarnopolsky et al. (1988) found that only 0.37g/lb was required to maintain positive nitrogen balance in elite bodybuilders (over 5 years of experience, possible previous use of androgens) over a 10 day period. 0.45g/lb was sufficient to maintain lean body mass in bodybuilders over a 2 week period. The authors suggested that 0.55g/lb was sufficient for bodybuilders.
Lemon et al. (1992) found no differences in muscle mass or strength gains in novice bodybuilders consuming either 0.61g/lb or 1.19g/lb over a 4 week period. Based on nitrogen balance data, the authors recommended 0.75g/lb.
Hoffman et al. (2006) found no differences in body composition, strength or resting hormonal concentrations in strength athletes consuming either 0.77g/lb or >0.91g/lb over a 3 month period.
Effect of protein intake on strength, body composition and endocrine changes in strength/power athletes. Hoffman JR, Ratamess NA, Kang J, Falvo MJ, Faigenbaum AD. J Int Soc Sports Nutr. 2006 Dec 13;3:12-8.
Macronutrient content of a hypoenergy diet affects nitrogen retention and muscle function in weight lifters. Walberg JL, Leidy MK, Sturgill DJ, Hinkle DE, Ritchey SJ, Sebolt DR. Int J Sports Med. 1988 Aug;9(4):261-6.
Protein requirements and muscle mass/strength changes during intensive training in novice bodybuilders. Lemon PW, Tarnopolsky MA, MacDougall JD, Atkinson SA. J Appl Physiol. 1992 Aug;73(2):767-75.
Influence of protein intake and training status on nitrogen balance and lean body mass. Tarnopolsky MA, MacDougall JD, Atkinson SA. J Appl Physiol. 1988 Jan;64(1):187-93.
Dietary protein for athletes: From requirements to optimum adaptation. Phillips SM, Van Loon LJ. J Sports Sci. 2011;29 Suppl 1:S29-38.
Protein and amino acid metabolism during and after exercise and the effects of nutrition. Rennie MJ, Tipton KD. Annu Rev Nutr. 2000;20:457-83.
Hartman, J. W., Moore, D. R., & Phillips, S. M. (2006). Resistance training reduces whole-body protein turnover and improves net protein retention in untrained young males. Applied Physiology, Nutrition and Metabolism, 31, 557–564.
Moore, D. R., Del Bel, N. C., Nizi, K. I., Hartman, J. W., Tang, J. E., Armstrong, D. et al. (2007). Resistance training reduces fasted- and fed-state leucine turnover and increases dietary nitrogen retention in previously untrained young men. Journal of Nutrition, 137, 985–991.
Effects of exercise on dietary protein requirements. Lemon PW. Int J Sport Nutr. 1998 Dec;8(4):426-47.
Effects of high-calorie supplements on body composition and muscular strength following resistance training. Rozenek R, Ward P, Long S, Garhammer J. J Sports Med Phys Fitness. 2002 Sep;42(3):340-7.
Increased protein maintains nitrogen balance during exercise-induced energy deficit. Pikosky MA, Smith TJ, Grediagin A, Castaneda-Sceppa C, Byerley L, Glickman EL, Young AJ. Med Sci Sports Exerc. 2008 Mar;40(3):505-12.
Dietary carbohydrate-to-fat ratio: influence on whole-body nitrogen retention, substrate utilization, and hormone response in healthy male subjects. McCargar LJ, Clandinin MT, Belcastro AN, Walker K. Am J Clin Nutr. 1989 Jun;49(6):1169-78.
Macronutrient Intakes as Determinants of Dietary Protein and Amino Acid Adequacy. Millward, DJ. J. Nutr. June 1, 2004 vol. 134 no. 6 1588S-1596S.