Exceptional body composition changes attributed to collagen peptide supplementation and resistance training in older sarcopenic men

Abstract The results reported by Zdzieblik et al.(1), on gains in fat-free mass (FFM: mean 4·2 (SD 3·3) kg) and loss of body fat (mean −5·5 (SD 3·2) kg) in older sarcopenic men receiving 15 g/d of collagen peptides while resistance training for 12 weeks, are extraordinary. The algebraic difference between the collagen peptide-supplemented and placebo groups in terms of FFM reported by Zdzieblik et al.(1) was approximately 1·3 kg, which is 2·7 and 5·6 times greater than the standardised mean differences reported in meta-analyses from Cermak et al.(2) and Finger et al.(3), which examined the impact of protein supplementation on resistance exercise-induced gains in FFM. Neither meta-analysis reported an impact of protein supplementation on loss of fat mass