ABSTRACT

1. THE EFFECTS OF A SUPPLEMENT DESIGNED TO ATTENUATE THE ADVERSE EFFECTS OF FATIGUE Adam J. Wells, Adam M. Gonzalez, Gerald T. Mangine, Nadia S. Emerson, William P. McCormack, Adam R. Jajtner, Jeremy R. Townsend, Tyler C. Scanlon, Edward H. Robinson IV, Jeffrey R. Stout, FACSM, Jay R. Hoffman, FACSM, and Maren S. Fragala Institute of Exercise Physiology & Wellness, University of Central Florida, Orlando, FL, USA, Table 2: POMS ABSTRACT METHODS CONT. RESULTS CONT. RESULTS CONT. • 1-repetition maximum (1-RM) was determined in the bench-press and barbell back squat exercises. A 10-RM was determined for deadlift, incline bench-press and bent-over row exercises. • Statistical analysis of the data was accomplished using a 2 x 2 (time x treatment) repeated measures analysis of variance (ANOVA) at T1 and T2. In the event of a significant F-ratio, Bonferroni post-hoc tests were used for pairwise comparisons. Phosphatidylserine (PS) supplementation may play a role in attenuating the adverse effects of physical fatigue on cognition, mood, and motor function. However, the results from recent investigations remain equivocal. PURPOSE: To examine the effect of ingesting a supplement (S) containing PS (400 mg·day-1) and caffeine (100 mg·day-1) for 14 days, on measures of cognitive function (CF), reaction time (RT), and mood (MD), following an acute exercise stress. METHODS: Twenty-one recreationally trained men and women (age: 22.5 ± 3.4 yrs; height: 1.76 ± 1.0 m; weight: 77.6 ± 12.6 kg; body fat: 14.6 ± 6.6 %) volunteered for this double-blind, controlled study. Participants completed two acute bouts of resistance exercise (T1 and T2), separated by two weeks of supplementation with S or control (C). Measures of RT (Dynavision D2), CF (Serial Subtraction Test), and MD (Profile of Mood States) were assessed pre and post exercise at T1 and T2. A 2 x 2 (time x treatment) repeated measures analysis of variance was used to analyze the data. RESULTS: When collapsed across groups, a significant decrease (p = 0.05) in RT performance (# of strikes) was seen in the 60-second reaction drill from pre to post exercise at T1. All other RT tests were similar from pre to post exercise at T1. RT was not significantly changed in response to PS (p > 0.05), and no significant between group differences were noted at T2.When collapsed across groups, a significant increase in the number of correct answers, and a significant decrease in time to answer was seen from pre to post workout at T1 (p = 0.004 and p = 0.007, respectively) and T2 (p = 0.004 and 0.018, respectively) in the CF test. A significant increase in total mood score was observed for C but not for S (p = 0.034). Additionally, C experienced a 13% greater increase (p = 0.031) in pre to post exercise perception of fatigue compared to S. A significant decrease in confusion was observed in S at T2 (p = 0.041). CONCLUSION: Ingestion of 400 mg·day-1 PS and 100 mg·day-1 of caffeine for 14-days appears to attenuate post-exercise MD scores and perception of fatigue, but does not improve reaction time in recreationally trained individuals following acute resistance exercise. An acute bout of resistance exercise may improve CF; however, PS provides no further benefit. Figure 2:Changes in mood disturbance from pre to post workout following 14 days supplementation with 400 mg·day-1 PS and 100 mg·day-1 of caffeine. * Significant change within groups p = ≤ 0.05; $ Significant interaction between groups p = ≤ 0.05 • Serial Subtraction Test. Two-minute timed verbal test in which participants were required to subtract the number 7 from a random computer generated four-digit number. * = Main effect p = ≤ 0.05. Data presented as Mean ± SD. Study Design Schematic Table 3: Serial Subtraction Test • Measures • Visual and motor and physical reaction time were assessed with the Dynavision® D2 Visuomotor training device. • Cognitive function was assessed using a verbally administered Serial Subtraction Test. • Mood was assessed using the Profile of Mood States Questionnaire (POMS). INTRODUCTION • PS is a phospholipid found predominantly in the myelin of brain tissue. • Prior research indicates that PS is a key activator of protein kinases responsible for the modulation of nerve cell integrity [1,2]. • Previous studies have shown that PS can significantly enhance cognition [3] and time to exhaustion [4,5]. • The integration of supplemental PS into cellular membranes may stimulate neural amplification, possibly augmenting both cognition and motor function [6,7], however the efficacy of supplemental PS remains equivocal. • Differences in the findings of previous studies may be related to the level of fatigue associated with the protocol. RESULTS * = Main effect p = ≤ 0.05. Data presented as Mean ± SD. • Reaction Time • No significant differences were seen in visual, motor, or physical RT from PRE to POST workout at T1 (p = 0.853, p = 0.224 and p = 0.294 respectively) or T2 (p = 0.502, p = 0.841 and p = 0.646 respectively). • Cognition • A significant increase in the number of correct answers was seen pre to post exercise at both T1 (p = 0.004) and T2 (p = 0.004) in the serial subtraction test. A significant decrease in time to answer was seen at both T1 (p = 0.007) and T2 (p = 0.018). • No differences were noted between groups at T1 or T2 in any of the serial subtraction tests. • Mood • T1 • At T1, significant increases were seen in total mood score (TMS; p = 0.000), fatigue (p = 0.000), tension (p = 0.034) and depression (p = 0.048), with a significant decrease in vigor (p = 0.021 from PRE to POST workout. • No changes were noted in confusion or anger at T1. • T2 • A significant interaction (p=0.034) for TMS was observed at T2. Post-hoc analysis demonstrated a significant increase in TMS for CON (p = 0.003) however, no significant change was observed for SUP (p = 0.166). • Significant elevations in fatigue were observed in CON (p=0.00) and SUP (p=0.016) following the workout at T2. However, significant interaction (p=0.031) indicates that the magnitude of change in fatigue was greater in CON (+29%) compared to SUP (+16%). SUMMARY & CONCLUSIONS • Ingestion of 400 mg·day-1 of PS for 14-days attenuates post-exercise mood scores and perception of fatigue. • Participants ingesting PS were able to maintain TMS from pre to post exercise, while participants consuming a control experienced a significant increase in total mood disturbance. • Perception of fatigue from pre to post-exercise was significantly attenuated in participants ingesting PS. • An acute bout of resistance exercise appears to improve cognitive performance; however PS provides no further benefit. • Supplementing with PS does not appear to improve reaction time. Table 1: Reaction Time PURPOSE • To examine the effects of 2 weeks supplementation with 400 mg·day-1 PS on measures of cognitive function, reaction time and mood in healthy young adults, following an acute exercise stress designed to elicit fatigue. REFERENCES Takai Y, Kishimoto A, Iwasa Y, Kawahara Y, Mori T, Nishizuka Y. Calcium-dependent activation of a multifunctional protein kinase by membrane phospholipids. J Biol Chem 1979;254:3692-5. Newton AC. Protein kinase C: structure, function, and regulation. J Biol Chem 1995;270:28495-8. Parker AG, Gordon J, Thornton A, Byars A, Lubker J, Bartlett M, Byrd M, Oliver J, Simbo S, Rasmussen C, Greenwood M, Kreider RB. The effects of IQPLUS Focus on cognitive function, mood and endocrine response before and following acute exercise. J Int Soc Sports Nutr 2011;8:16. Kingsley MI, Wadsworth D, Kilduff LP, McEneny J, Benton D. Effects of phosphatidylserine on oxidative stress following intermittent running. Med Sci Sports Exerc 2005;37:1300-6.3 Kingsley MI, Miller M, Kilduff LP, McEneny J, Benton D. Effects of phosphatidylserine on exercise capacity during cycling in active males. Med Sci Sports Exerc 2006;38:64-71. Funfgeld EW, Nedwidek P. Neurohomologous phosphatidylserine in Parkinsonian subjects with associated disorders of cerebral metabolism. Clinical Trials Journal 1987;24:42-61. Kennedy DO, Haskell CF, Mauri PL, Scholey AB. Acute cognitive effects of standardized ginkgo biloba extract complexed with phosphatidylserine. Human Psychopharmacology 2007;22:199-210. METHODS • Twenty-one healthy resistance trained men (n=17) and women (n=4); age: 22.5 ± 3.4 yrs; height: 1.76 ± 1.0 m; weight: 77.6 ± 12.6 kg; body fat: 14.6 ± 6.6 %; completed two acute bouts of resistance exercise. • Measures of reaction time, cognition and mood state were assessed immediately pre and post workout at T1 and T2. • The exercise protocol consisted of 4 sets of 10 repetitions at 70% of 1-RM with 90 s rest between sets and exercises. • Dynavision D2 Visuomotor Training Device Figure 1: Changes in mood disturbance from pre to post workout following 14 days supplementation with 400 mg·day-1 PS and 100 mg·day-1 of caffeine. * = Main effect p = ≤ 0.05. Data presented as Mean ± SD.