Author(s): REHRER, N., MURRAY, M., BEST, A., SIMS, S., LOEHR, J., Institution: UNIVERSITY OF OTAGO, Country: NEW ZEALAND, Abstract-ID: 2554

INTRODUCTION:
The aim of the study was to investigate effects of 12 wk training with post-exercise protein supplementation on body composition in untrained, healthy females.
METHODS:
Participants (n = 27, 33.1 ± 9.2 y, mass 69.5 ± 13 kg, BMI < 30, VO2max 27.3 + 3.7 ml/kg/min) undertook upper-body resistance training (2 x/wk) and HIIT cycling (3 x/wk). Participants were told this is not a weight loss programme and they should adjust dietary intakes to maintain weight.Dietary intakes (3-day record) were measured at wk 0,4,8,12, body composition (DXA) at wk 0 and 12. Participants consumed either a high- (24 g, N = 15 ,P) or equicaloric low- (3 g, N = 12, C) protein post-exercise supplement (510 kJ).
RESULTS:
Average daily intakes of total energy wk 4-12 in P and C (7.2 ± 1.1 , 7.9 ± 1.1 MJ, resp. P = 0.17 ) and protein (90 ± 14 , 85 ± 12 g., resp. P = 0.28 ) were similar. There was little change in body mass with training (P =0.56) and no significant difference between P and C (Δ 0.04 ± 2.2 kg, 0.38 ± 1.3, resp. P=0.64).
There was a large variability in change in fat mass such that the change over time was not significant (P = 0.12). There was no difference between P and C (Δ -0.5 ± 1.9 , - 0.5 ± 1.2 kg, resp. P = 0.98). Participants gained lean mass (P = 0.008) but there was no difference between P and C (Δ 0.6 ± 1.4 , 0.8 ± 0.8 kg, resp. P = 0.56).
CONCLUSION:
Post-exercise protein supplementation (24 g) appears not to impact body composition changes in normal weight, healthy, untrained women who undergo 12 wk of mixed aerobic and resistance training. The fact that total dietary intakes of protein did not differ between groups and that protein was likely in excess of needs (~1.2 g/kg) likely account for the lack of effect of protein supplementation on body composition.