Author(s): MURRAY, M.1, BEST, A.1, SIMS, T.S.2, LOEHR, J.A.1, REHRER, N.J.1, Institution: UNIVERSITY OF OTAGO, Country: NEW ZEALAND, Abstract-ID: 2535

INTRODUCTION:
The aim of the study was to investigate the effects of post-exercise protein supplementation on training responses 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) completed 12 wk upper-body resistance training (2 x/wk) and HIIT cycling (3 x/wk). VO2max, 3RM (shoulder, row, bench) IGF-1 and 3-day dietary records were measured at wk 0 and 12. Participants consumed either a high- (24 g, P) or equicaloric low- (3 g, C) protein post-exercise supplement (510 kJ).

RESULTS:
Average daily intakes of total energy for P and C (7225 kJ ± 1116, 7881 kJ ± 1138, resp. P = 0.170), protein (90.8 g ± 14.2, 84.8 g ± 12.1, resp. P = 0.278) were similar. Significant training effects were observed with a 17.2% ± 13.3 increase in VO2 max (P <0.001) and a 50% ± 15.7 increase in average 3RM (P <0.001). No significant differences between P and C were observed in VO2max (4.5 ml/kg/min ± 3.37, 4.6 ml/kg/min ± 3.42, resp. P = 0.935) or 3RM (P= 6.48 kg ± 1.28, C= 7.09 kg ± 2.30, resp. P = 0.386). IGF-1 did not change with training (Δ-3.83 ± 27.3) and was not different between treatments (ΔP= -2.05 ± 27.8, ∆C = -6.04 ± 27.7, resp. P = 0.714). Average number of total sessions for P and C were (85.5% ± 9.52, 86.0 ± 17.8, resp. P = 0.928). Average number of resistance sessions for P and C were (88.7% ± 7.67, 89.9 ± 7.49, resp. P = 0.697). Average number of aerobic sessions for P and C were (82.4 ± 13.2, 90.9 ± 7.38, resp. P = 0.069).
CONCLUSION:
The lack of effect of post-exercise protein supplementation on training responses is likely due to the fact that total dietary protein intake was unaltered. This study highlights the fact that consuming a protein supplement does not necessarily alter overall dietary intake as compensation can occur. These results also highlight the fact that untrained females can tolerate and adapt to exercise loads that are typically recommended, based on data from male responses.