Chronic beetroot juice supplementation attenuates neuromuscular fatigue etiology during simulated soccer match play.

The aim of the present study was to assess the effect of beetroot juice supplementation (BEET) on neuromuscular fatigue etiology during simulated soccer match play. In a randomized, double-blind, crossover design, 13 soccer players completed the Loughborough Intermittent Shuttle Test (LIST). Players received either BEET (2×150 mL; ∼8 mmol/L nitrate) or placebo (PLA) for 7 days (6 days prior to the experimental session and on the day of trial, 2 h before LIST). Neuromuscular assessments were performed at baseline, 45 min (half time: HT), and 90 min (full time: FT) following LIST. Maximal voluntary contraction (MVC) and twitch responses, delivered through electrical femoral nerve stimulation, were used to assess peripheral (quadriceps resting twitch force Qtw,pot) and central fatigue (voluntary activation, VA). Compared with baseline, MVC Qtw,pot and VA values decreased in PLA and BEET conditions at HT and FT (P < 0.05). Compared with PLA, the decrease in MVC and Qtw,pot was significantly attenuated with BEET at HT and FT (P < 0.001). Likewise, BEET attenuated the decrease in VA at HT (P < 0.001, d = 1.3) and FT (P < 0.001, d = 1.5) compared with the PLA condition. Chronic beetroot juice supplementation attenuates neuromuscular fatigue development during simulated soccer matches, and this is due to both central and peripheral factors. Consequently, chronic beetroot may optimize physical performance.

Salivary hormones and anxiety in winners and losers of an international judo competition.

The purpose of this study was to investigate the responses of salivary hormones and salivary secretory immunoglobulin A (SIgA) and anxiety in winners and losers during an international judo competition. Twenty-three trained, male, national-level judo athletes provided three saliva samples during a competition day: morning, in anticipation of competition after an overnight fast, mid-competition, and post-competition within 15 min post-fight for determination of salivary cortisol, salivary testosterone, salivary testosterone/cortisol ratio, SIgA absolute concentrations, SIgA secretion rate and saliva flow rate. The competitive state anxiety inventory questionnaire was completed by the athletes (n = 12) after the first saliva collection for determination of somatic anxiety, cognitive anxiety and self-confidence. Winners were considered 1-3 ranking place (n = 12) and losers (n = 11) below third place in each weight category. Winners presented higher anticipatory salivary cortisol concentrations (p = 0.03) and a lower mid-competition salivary testosterone/cortisol ratio (p = 0.003) compared with losers with no differences for salivary testosterone. Winners tended to have higher SIgA secretion rates (p = 0.07) and higher saliva flow rates (p = 0.009) at mid-competition. Higher levels of cognitive anxiety (p = 0.02) were observed in the winners, without differences according to the outcome in somatic anxiety and self-confidence. The results suggest that winners experienced higher levels of physiological arousal and better psychological preparedness in the morning, and as the competition progressed, the winners were able to control their stress response better.

Effects of acute postexercise chocolate milk consumption during intensive judo training on the recovery of salivary hormones, salivary SIgA, mood state, muscle soreness, and judo-related performance.

This study examined the effects of postexercise chocolate milk (CM) or water (W) consumption during 5 days of intensive judo training with concomitant weight loss on salivary cortisol and testosterone, salivary secretory immunoglobulin A (SIgA), delayed-onset muscle soreness (DOMS), and judo-related performance. Twelve trained male judo athletes engaged in 5 days of intensive judo training followed by a simulated judo competition, on 2 separate training weeks 14 days apart. The athletes consumed 1000 mL of W (week 1) or CM (week 2) immediately post-training. During both weeks, athletes were instructed to "make weight" for the upcoming competition. Performance in timed push-ups and the Special Judo Fitness Test improved by 14.6% and 6.8%, respectively, at the end of the training week with CM consumption (both p < 0.001). Decreased salivary cortisol (p < 0.01) and a trend for an increased salivary testosterone/cortisol ratio (p = 0.07) were also observed midweek in the CM condition. Saliva flow rate was higher during the week with CM intake compared with W intake (p < 0.001). DOMS (p < 0.001) and mood disturbance (p < 0.0001) increased after the first day of training in the W condition but not in the CM condition. Salivary testosterone and SIgA responses were similar between treatments (p > 0.05). Body mass decreased by 1.9% in the W condition and by 1.1% in the CM condition, with no significant difference between treatments. This study indicates that postexercise CM consumption during short-term intensive judo training enhances aspects of recovery without affecting intentional weight loss.

Salivary hormones, IgA, and performance during intense training and tapering in judo athletes.

The aims of this study were to identify the time course of change of salivary testosterone (sT), cortisol (sC), and IgA (SIgA); mood state; and performance capacity during a 2-week taper in judo athletes and to examine the diurnal variation in these salivary markers. Eleven male judo athletes completed 5 weeks of training: 1 week of normal training (NORM), 2 weeks of intensified training (INT), and 2 weeks of exponential tapering (TAPER). Once per week subjects completed vertical and horizontal countermovement jump tests, a grip strength test, a Special Judo Fitness Test, a multistage aerobic fitness test, a 3 × 300-m run test, and anthropometric measurement. Subjects also completed questionnaires to assess mood state and muscle soreness. Two daily saliva samples (at 0700 and 1900) were collected at the end of each week during NORM and INT and every day during TAPER. Increased morning sT, decreased evening sC, lower muscle soreness, and enhanced mood state (p < 0.05) were evident by the early phases of TAPER. A significant 7.0% improvement in 3 × 300-m performance time, a 6.9% improvement in the vertical jump (p < 0.05), and increased morning and evening SIgA secretion rate (p < 0.01) were observed during the middle-late phases of TAPER. The higher values of salivary variables were observed in the morning. This study indicates that salivary hormones display diurnal variation. Furthermore, changes in hormonal responses, mood state, and muscle soreness precede enhancements in performance and mucosal immunity, suggesting that judo athletes taper for at least a week before competition.