In randomized controlled trials (RCTs) of phosphatidylserine (PS) in athletic populations, PS did not consistently improve the outcomes examined.
A pair of 2006 RCTs from a team of UK researchers tested PS supplementation in cycling and downhill running. The participants in the PS groups in both studies took a large dose of PS (750 mg) for 10 days before the exercise bout. In the cycling study, time to exhaustion in the PS group improved significantly compared to that of the placebo group. The increase in the PS group was dramatic — from nearly 8 minutes to nearly 10 minutes. No significant differences were found in any of the other outcomes the study measured, including lower-intensity performance, fatigue levels, and serum cortisol levels.[1] The second study didn't report on the participants' time to exhaustion, but focused on muscle soreness and biomarkers of muscle damage and exercise-induced inflammation and oxidative stress. The study found no significant differences between the participants who received PS and those who received a placebo.[2]
Unlike the 2006 cycling study, which found no significant difference in cortisol, a 2008 crossover study of PS supplementation and cycling found that participants' post-exercise cortisol area under the curve was lower after PS supplementation. The study found no significant difference in the other outcomes. This RCT looked at the participants' serum cortisol, lactate, testosterone and growth hormone after a bout of moderate-intensity to high-intensity cycling, conducted after 10 days of supplementation with either 600 mg of PS or a placebo.[3] Another crossover study, this one in resistance-trained young men, also found no significant differences in post-exercise mood, serum cortisol levels, or serum testosterone levels between participants who had taken 400 mg of PS for 14 days and those who had taken a placebo. However, participants in the PS group did perform better on 1 of 3 metrics related to performing simple math problems quickly.[4]
The participants who took a combined PS (400 mg) and caffeine (100 mg) supplement for 2 weeks reduced their fatigue ratings immediately after resistance training, compared to a placebo. However, caffeine is known to reduce fatigue ratings,[5] so it is difficult to say how much PS contributed. Outcomes whose improvements could have more clearly been attributed to PS, such as mood and cognition, were not improved with supplementation compared to a placebo.[6]
References
- ^Kingsley MI, Miller M, Kilduff LP, McEneny J, Benton DEffects of phosphatidylserine on exercise capacity during cycling in active malesMed Sci Sports Exerc.(2006 Jan)
- ^Kingsley MI, Kilduff LP, McEneny J, Dietzig RE, Benton DPhosphatidylserine supplementation and recovery following downhill runningMed Sci Sports Exerc.(2006 Sep)
- ^Starks MA, Starks SL, Kingsley M, Purpura M, Jäger RThe effects of phosphatidylserine on endocrine response to moderate intensity exercise.J Int Soc Sports Nutr.(2008-Jul-28)
- ^Parker AG, Gordon J, Thornton A, Byars A, Lubker J, Bartlett M, Byrd M, Oliver J, Simbo S, Rasmussen C, Greenwood M, Kreider RBThe effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exerciseJ Int Soc Sports Nutr.(2011 Oct 21)
- ^Nanci S Guest, Trisha A VanDusseldorp, Michael T Nelson, Jozo Grgic, Brad J Schoenfeld, Nathaniel D M Jenkins, Shawn M Arent, Jose Antonio, Jeffrey R Stout, Eric T Trexler, Abbie E Smith-Ryan, Erica R Goldstein, Douglas S Kalman, Bill I CampbellInternational society of sports nutrition position stand: caffeine and exercise performanceJ Int Soc Sports Nutr.(2021 Jan 2)
- ^Wells AJ, Hoffman JR, Gonzalez AM, Stout JR, Fragala MS, Mangine GT, McCormack WP, Jajtner AR, Townsend JR, Robinson EHPhosphatidylserine and caffeine attenuate postexercise mood disturbance and perception of fatigue in humans.Nutr Res.(2013-Jun)