title: Effects of ingesting a pre-workout dietary supplement with and without synephrine for 8 weeks on training adaptations in resistance-trained males.
abstract: BACKGROUND
  The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males.
  
  
  METHODS
  Resistance-trained males (N= 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg),Mucuna pruiriensextract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement withCitrus aurantiumextract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training. Participants donated a fasting blood sample and had body composition (DXA), resting heart rate and blood pressure, cognitive function (Stroop Test), readiness to perform, bench and leg press 1 RM, and Wingate anaerobic capacity assessments determined a 0, 4, and 8-weeks of standardized training. Data were analyzed by MANOVA with repeated measures. Performance and cognitive function data were analyzed using baseline values as covariates as well as mean changes from baseline with 95% confidence intervals (CI). Blood chemistry data were also analyzed using Chi-square analysis.
  
  
  RESULTS
  Although significant time effects were seen, no statistically significant overall MANOVA Wilks' Lambda interactions were observed among groups for body composition, resting heart and blood pressure, readiness to perform questions, 1RM strength, anaerobic sprint capacity, or blood chemistry panels. MANOVA univariate analysis and analysis of changes from baseline with 95% CI revealed some evidence that cognitive function and 1RM strength were increased to a greater degree in the PWS and/or PWS + S groups after 4- and/or 8-weeks compared to PLA responses. However, there was no evidence that PWS + S promoted greater overall training adaptations compared to the PWS group. Dietary supplementation of PWS and PWS + S did not increase the incidence of reported side effects or significantly affect the number of blood values above clinical norms compared to PLA.
  
  
  CONCLUSIONS
  Results provide some evidence that 4-weeks of PWS and/or PWS + S supplementation can improve some indices of cognitive function and exercise performance during resistance-training without significant side effects in apparently health males. However, these effects were similar to PLA responses after 8-weeks of supplementation and inclusion of synephrine did not promote additive benefits.
  
  
  BACKGROUND
  This trial (NCT02999581) was retrospectively registered on December 16th 2016.
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Y Peter
authors.initials: YP
authors.lastname: Jung
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA ; Nutrabolt, Bryan, TX 77807 USA.
authors.forename: Conrad P
authors.initials: CP
authors.lastname: Earnest
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Majid
authors.initials: M
authors.lastname: Koozehchian
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Minye
authors.initials: M
authors.lastname: Cho
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Nick
authors.initials: N
authors.lastname: Barringer
authors.affiliation: Department of Health & Kinesiology, Center for Translational Research in Aging and Longevity, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Dillon
authors.initials: D
authors.lastname: Walker
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Rasmussen
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Mike
authors.initials: M
authors.lastname: Greenwood
authors.affiliation: Department of Nutrition and Food Sciences, Institute for Obesity Research & Program Evaluation, Texas A&M University, College Station, TX 77843 USA.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Murano
authors.affiliation: Exercise & Sport Nutrition Lab, Department of Health & Kinesiology, Texas A&M University, College Station, TX 77843-4243 USA.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Kreider
mesh_terms: D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D008297:Male; D010807:Physical Endurance; D055070:Resistance Training; D064133:Sports Nutritional Physiological Phenomena; D013578:Synephrine / Q000008:administration & dosage*; D016896:Treatment Outcome; D055815:Young Adult; D015091:beta-Alanine / Q000008:administration & dosage*
chemical_list: D015091:beta-Alanine; D013578:Synephrine
keywords: Body composition; Cognitive function; Dietary supplement; Ergogenic aids; Exercise performance; Multi-ingredient supplement; Safety