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Dietary nitrates have been shown to increase vasodilation, mitochondrial efficiency, muscle contractility, and reduce ATP turnover which has led to improvements in measures of athletic performance in previous work. PURPOSE: To observe the effects of dietary nitrates in the form of red spinach extract (RSE) on Division I collegiate baseball players following off-season training on health and performance measures. METHODS: Division I male baseball athletes (N=16; 20.5 ± 1.7y; 90.4 ± 10.5kg; 1.82 ± 0.61m) participated in this doClinuble-blind, placebo-controlled, randomized study. Before and after 11-weeks of offseason training, athletes were tested for body composition via dual x-ray absorptiometry, muscle thickness (MT) of the rectus femoris (RF) and vastus lateralis (VL) via muscle ultrasonography, resting heart rate (HR), and blood pressure (BP) in addition to a one-repetition maximum (1RM) on bench press and a maximal Wingate anaerobic cycle test (WAnT) to evaluate physical performance. After random assignment, participants consumed 2g of RSE, or a placebo (PL) (n = 8) daily for 12 weeks. Training consisted of 2-3 days per week of a triphasic undulating resistance training program in addition to sport specific activities. Changes were analyzed using a two factor (Time x Group) between-subjects repeated measures analysis of variance. RESULTS: There were no significant time x group interactions observed for any measure of body composition, physical performance, or health (all p > 0.05). However, a trend for increased peak power in the WAnT was found for the RSE group (p = 0.095; η² = 0.200). A main effect for time was observed for training improvements in bench press 1RM (p < 0.001; η² = 0.688), increased fat-free mass (p < 0.001; η² = 0.737) and MT for the RF and VL (p < 0.001), as well as a decrease in fat mass (p = 0.005; η² = 0.449) and body fat percentage (p = 0.002; η² = 0.512). Systolic BP exhibited an increase with both groups combined (p = 0.044; η² = 0.258) with no other significant changes in HR or BP were found. Compliance for supplement intake averaged 94.9% and no significant differences between groups were observed for macronutrient or calorie intake. CONCLUSION: Chronic dietary nitrate supplementation in the form of RSE may not improve indices of health, performance, or body composition in collegiate baseball athletes. [ABSTRACT FROM AUTHOR]

Dietary nitrates have become a popular dietary supplement to improve overall health and exercise performance, in part, due to their proposed ability to improve blood flow to active musculature. However, current data regarding increased muscle blood flow following dietary nitrate consumption have been equivocal. PURPOSE: To assess the impact of 6 days of dietary nitrate loading, in the form of red spinach extract (RSE), on muscle oxygenation during a fatiguing barbell bench press protocol. METHODS: Ten resistance-trained males (22.7 ± 3.2 yrs, 80.5 ±3 .9kg, 1.79 ± 7.4m, 7.4 ± 3.2 yrs of training experience) participated in this randomized, cross-over, placebo-controlled, double-blind investigation. Each participant completed 6 days of either RSE (2g) or a maltodextrin placebo (PL) before reporting to the lab for testing in a counterbalanced fashion with a 14-day washout period between treatments. Upon reporting to the lab, participants were provided their last dose of RSE or PL 40 minutes before beginning a standardized warm-up and then completing 5 sets of the barbell bench press exercise at 75% of a predetermined 1-repetition maximum with 2-minute rest intervals. Participants were instructed to complete as many repetitions as possible until muscular failure. Percentage of oxygen saturation loss (Δ%SmO2) during each bench press set, reoxygenation slope of the first 30 seconds of recovery following each set (SmO2slope), and total reoxygenation time (SmO2recT) in recovery following each set were assessed using a near-infrared spectroscopy device (NIRS). Data were analyzed via separate repeated measures analyses of variance. RESULTS: There were no significant time by group interactions for Δ%SmO2 (p = 0.143), SmO2recT (p = 0.368), or SmO2slope (p = 0.719) indicating similar responses between treatments. A trend for a main effect for time was observed for SmO2slope (p = 0.055; η² = 0.137) with the recovery slope declining over the 4 rest periods between bench press sets. No other main effects for time were observed (p > 0.05). CONCLUSION: It appears that 6 days of dietary nitrate loading did not alter NIRS derived muscle oxygenation measures of the anterior deltoid during the bench press exercise in resistance- trained males. [ABSTRACT FROM AUTHOR]