254 901 Board #217 June 1, 3:30 PM - 5:00 PM Effects Of Short-term Pre-workout Supplement Ingestion At Different Dosages On Exercise Performance Y. P. Jung 1 , M. Koozechian 1 , A. O’Connor 1 , S. Shin 1 , P. B. Collins 1 , R. Dalton 1 , T. Grubic 1 , R. Sowinski 1 , B. K. Sanchez 1 , A. Coletta 1 , M. Cho 1 , A. Reyes 1 , C. Rasmussen 1 , P. S. Murano 1 , M. Greenwood, FACSM 1 , C. P. Earnest, FACSM 2 , R. B. Kreider, FACSM 1 . 1 Texas A&M University, College Station, TX. 2 Nutrabolt International, Bryan, TX. (Sponsor: Richard Kreider, FACSM) (No relationships reported) PURPOSE: As part of a 7-d safety study, we examined the short-term of a dietary pre-workout supplement (PWS) at difference doses on strength and Wingate anaerobic capacity as a secondary outcome. METHODS: We recruited 19 apparently healthy and recreationally active men and women (21.8±2.1 yr, 21.6±8.7 %fat, 26.9±3.8 kg/m2) with at least 6-months of resistance training, to participate in a double-blind, crossover, randomized and placebo-controlled manner. We instructed subjects to maintain their current diet and training regimens throughout the study. Supplements were (1) a dextrose placebo (PLA, 12 g/d); (2) a PWS supplement containing 4.7g B-alanine, 1.6g creatine nitrate, 1.0g arginine AKG, 250mg ascorbic acid, 150mg N-acetyl tyrosine, 150mg caffeine and 5mg tetramethyluric acid; or (3) PWS at ~150% dosage (PWS150) of the base formula for seven days, interspersed with 7-d of washout. On Day 1 (acute) and Day 7 (chronic), subjects were measured fasted (12h), before ingesting their respective supplements. Testing was initiated 30-min after supplement ingestion and strength was assessed as bench and leg press volume, defined as repetitions to fatigue during set three following two sets of 10 reps at 70% of 1RM for each lifting movement. Data were analyzed using a repeated measure MANOVA and are presented as mean change from baseline and 95% CI. RESULTS: No significant effects were noted for strength or Wingate performance including: (1) Bench Press Lifting Volume (kg): PLA (4.9; 95% CI -99.1, 108.9), PWS (-82.0; 95% CI -186.0, 21.9) and PWS150 (85.7; 95% CI -18.2, 189.7); (2) Leg Press Lifting Volume (kg): PLA (174.7; 95% CI -921.9, 1271.2), PWS (670.1; 95% CI -426.5, 1766.6) and PWS150 (789.7; 95% CI -306.9, 1886.2), (3) Wingate Average Power (W): PLA (15.2; 95% CI -9.9, 40.4), PWS (10.7; 95% CI -14.5, 35.9) and PWS150 (17.6; 95% CI - 7.6, 42.7) or (4) Wingate Peak Power (W): PLA (-11.0; 95% CI -134.5, 112, 4), PWS (-30.0; 95% CI -153.6, 93.2), and PWS150 (34.9; 95% CI -88.5, 158.3). CONCLUSIONS: The PWS formulae used in this study do not appear to increase various indices of physical performance over a seven day period; it is suggested that a longer period of study is necessary to determine the potential ergogenic benefits of such a supplement regimen. Supported by Nutrabolt Int. 902 Board #218 June 1, 3:30 PM - 5:00 PM Muscle Sentry® Has No Effect On Estimated Cardiac Vo2 After A Bout Of Resistance Training. Arnold G. Nelson, FACSM 1 , Junghai Xu 1 , Tyler M. Farney 1 , Joke Kokkonen 2 . 1 LSU, Baton Rouge, LA. 2 BYU-Hawaii, Laie, HI. Email: anelso@lsu.edu (No relationships reported) Muscle Sentry® is an exercise supplement that its manufacturer claims will give a person “gains in stamina and endurance, and increased cardiovascular efficiency” in both aerobic and anaerobic work. However, data concerning Muscle Sentry®’s influence on increased endurance and cardiovascular eff iciency are only based on increases in VO2max. Actual changes in performance and cardiac work (i.e. heart VO2) have not been reported. PURPOSE: This study compared the total weight lifted and post-exercise estimated cardiac VO2 while on either Muscle Sentry® (MS) or placebo (PL). METHODS: Participants (11 women, 10 men, college students 20-24 years) performed 3 sets to failure of both chest and leg press using a load equal to their eight repetition maximum with 1 min rest separating each set. Each exercise was performed four times (2x MS, 2x PL) at the same time of day with 48 h separating each exercise. Both MS and PL were ingested 30 min prior to performing the exercise. Just prior to starting the exercise and immediately at the end of each set, both heart rate and blood pressure were obtained. The rate pressure product (RPP) was then calculated to determine estimated cardiac VO2. Daily RPP and total weight lifted (chest+leg) for each supplementation were averaged together, and each average final RPP was divided by the total weight lifted to obtain a normalized value. RESULTS: Paired t-tests for total weight lifted (mean ± std. dev.: MS= 58334 ± 27213 N, PL= 59013 ± 28240 N) showed no significance between MS and PL. In addition, the adjusted RPP (MS= 0.308 ± 0.127, PL= 0.316 ± 0.135) was not significantly different. CONCLUSIONS: Ingestion of Muscle Sentry® 30 min prior to doing 3 sets to failure of both chest and leg presses had no effect upon either total work lifted or estimated cardiac VO2. This suggests that, in some instances, the benefits of Muscle Sentry® are less than those claimed by the manufacturer. 903 Board #219 June 1, 3:30 PM - 5:00 PM Molecular Hydrogen Supplementation and Multiple Sprint Running Performance; a Pilot Investigation. Milan Pantovic 1 , Nikola Jevtic 2 , Dejan Magoc 3 , Jelena Obradovic 1 , Dejan Madic 1 , Glyn Howatson, FACSM 4 . 1 Faculty of Sport and Physical Education, Novi Sad, Serbia. 2 Scoliosis Rehabilitation Centre, Novi Sad, Serbia. 3 Stetson University, DeLand, FL. 4 Northumbria University, Newcastle upon Tyne, United Kingdom. (Sponsor: Glyn Howatson, FACSM) Email: milan.pantovic@yahoo.com (No relationships reported) Recently it has been suggested that molecular hydrogen could attenuate performance decrement during high intensity, short duration interval exercise. Antioxidant properties of molecular hydrogen indicate that it might be beneficial for reducing oxidative stress induced muscle performance decrements. PURPOSE:To examine the effects of molecular hydrogen supplementation on multiple sprint running performance. METHODS:Using a randomized, double-blind, crossover design, 15 physically active men ingested either molecular hydrogen-rich water (400 mg of molecular hydrogen) or a placebo, prior completing an indoor multiple sprint running (12 X 30 m; departing at 35-s intervals). Mean sprint time, fastest time, and fatigue index were recorded via twin- beam photocells, and earlobe blood samples were drawn to evaluate pretest and post-test lactate concentrations. Heart rate was monitored continuously throughout the tests, with RPE recorded after every second sprint. RESULTS:Relative to placebo, molecular hydrogen resulted in a 0.08-s (2%) reduction in mean sprint time (p < 0.05, 95% likely range = 0.04-0.09s) as well as 0.04-s (1%) reduction in fastest time (p < 0.01, 95% likely range = 0.05-0.06s), which corresponded in a 1% improvement in fatigue (p <0.05, 95% likely range = 0.8-1.1%). Molecular hydrogen supplementation also resulted in a 1-bpm increase in mean heart rate (169 ±17 versus 170 ±17; p < 0.01, 95% likely range = 0.3-3.5bpm). There was an increase in blood lactate over the course of each sprint trial (p < 0.01) which was greater in molecular hydrogen group (p < 0.05; 0.6 mMol·L ͋ -1; 95% likely range = 0.1-1.7 mMol·L ͋ -1). Rating of perceived exertion (RPE) showed a significant group effect (p < 0.01, 95% likely range = 0.9-1.6). CONCLUSIONS:Results of this pilot study indicate some ergogenic potential of molecular hydrogen supplementation on multiple sprint running performance. Further studies are needed in order to determine the dose response and the potential mechanisms of action for this intervention. Copyright © 2016 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.