Influence of Dietary Nitrate Supplementation on Physical Performance and Body Composition Following Offseason Training in Division I Athletes.

Purpose: To determine the effects of dietary nitrate supplementation, in the form of red spinach extract (RSE), on adaptations to offseason training in collegiate athletes.Methods: Sixteen Division I male baseball athletes (20.5 ± 1.7y, 90.4 ± 0.5 kg) enrolled in this study and were randomized into a RSE (n = 8) or placebo (n = 8; PL) group. Athletes completed an 11-week resistance training program during the offseason, which consisted of 2-3 workouts per week of upper and lower-body exercises and baseball-specific training. Athletes consumed a RSE (2 g; 180 mg nitrate) or PL supplement daily for the entire offseason training program. Pre and post-training, all athletes underwent one-repetition maximum (1RM) strength testing for the bench press and completed a Wingate anaerobic cycle test (WAnT). Body composition analysis was completed via a 4-compartment model, as well as muscle thickness (MT) measurement of the rectus femoris (RF) and vastus lateralis (VL) via ultrasonography. Resting heart rate and blood pressure (BP) were also obtained. Separate repeated measures analyses of variance were used to analyze all data.Results: Significant (p ≤ 0.05) main effects for time were observed for improved bench 1RM, fat-free mass, body fat percentage, RF MT, and VL MT. No significant group x time interactions (p > 0.05) were found for any measure of performance, body composition, or cardiovascular health. However, a trend for improved peak power in the WAnT was observed (p = 0.095; η2=0.200).Conclusions: These data suggest that daily RSE supplementation had no effect on performance, body composition, or cardiovascular measures in male Division I baseball players following offseason training.

Effects of Probiotic (Bacillus subtilis DE111) Supplementation on Immune Function, Hormonal Status, and Physical Performance in Division I Baseball Players.

We sought to determine the effects of probiotic supplementation (Bacillus subtilis DE111; 1 billion CFU∙d-1) on markers of immune and hormonal status in collegiate male athletes following 12 weeks of offseason training. Twenty-five Division I male baseball athletes (20.1 ± 1.5 years, 85.5 ± 10.5 kg, 184.7 ± 6.3 cm) participated in this double blind, placebo-controlled, randomized study. Participants were randomly assigned to a probiotic (PRO; n = 13) or placebo (PL; n = 12) group. Pre- and post-training, all athletes provided resting blood and saliva samples. Circulating concentrations of testosterone, cortisol, TNF-α, IL-10, and zonulin were examined in the blood, while salivary immunoglobulin A (SIgA) and SIgM were assayed as indicators of mucosal immunity. Separate analyses of covariance (ANCOVA) were performed on all measures collected post intervention. No differences in measures of body composition or physical performance were seen between groups. TNF-α concentrations were significantly (p = 0.024) lower in PRO compared to PL, while there were no significant group differences in any other biochemical markers examined. A main effect for time was observed (p < 0.05) for increased testosterone (p = 0.045), IL-10 (p = 0.048), SIgA rate (p = 0.031), and SIgM rate (p = 0.002) following offseason training. These data indicate that probiotic supplementation had no effect on body composition, performance, hormonal status, or gut permeability, while it may attenuate circulating TNF-α in athletes.