Phosphatidylserine supplementation and recovery following downhill running

This study investigated the effects of 750 mg of soybean-derived phosphatidylserine (S-PtdSer), administered daily for 7 d prior to a bout of eccentric exercise and for 2d following exercise, on delayed onset of muscle soreness and markers of muscle damage, inflammation, and oxidative stress that followed prolonged downhill running.

Following preliminary testing and a familiarization session, eight recreationally active males repeated an individualized downhill run at -16.5% for 51.0 +/- 1.5 min at 8.7 +/- 0.3 km x h(-1) on four occasions (trials 1-4). Trials 1 and 37 were presupplementation control trials. After trials 1 and 3 the subjects received, in a double-blind and crossover fashion, either S-PtdSer or a glucose polymer placebo. Trials 2 and 3 were separated by a 4-wk washout period. Venous blood, perceived soreness ratings, and feeling states were assessed prior to exercise, after exercise, and at 24 and 48 h after exercise during each trial.

Downhill running led to elevations in perceived soreness (P < 0.05), creatine kinase activities (P < 0.001), myoglobin concentrations (P < 0.001), interleukin-6 (IL-6) concentrations (P < 0.001), and lipid hydroperoxide concentrations (P < 0.01). However, supplementation did not significantly attenuate these responses.

These results suggest that supplementation with 750 mg x d(-1) S-PtdSer for 10 d does not afford additional protection against delayed onset of muscle soreness and markers of muscle damage, inflammation, and oxidative stress that follow prolonged downhill running.