Supplementation with an NR beetroot extract-based supplement provided neuromuscular advantages during metabolically taxing resistance exercise.

The purpose of this research was to determine the relationships between selected anthropometric and fitness measures with indicators of performance in elite junior Australian football players. During the pre-season, 485 players from the elite Victorian under-18 Australian Rules football competition were tested for height, body mass, hand span, arm length, standing reach, vertical jump, 5 and 20 m sprint times, agility, predicted VO(2max) and sit and reach flexibility. Performance indicators included being selected for the first game of the season and the number of possessions, marks, hitouts, and the number of games where votes were awarded in the first eight games of the season. The top and bottom four teams on the ladder were also compared after eight games. Players were divided into groups on the basis of the above indicators and the groups were compared statistically by analysis of variance (ANOVA). There were several significant differences between selected and non-selected players. Players acquiring the most possessions were significantly (p<0.05) shorter (effect size: ES=0.78), with less body mass (ES=0.55) and possessed greater acceleration (ES=0.44-0.56) and endurance (ES=0.51). Body mass was significantly related to the number of marks and height was related to hitouts (p<0.05). Acceleration was the only fitness quality to discriminate between higher and lower vote winners. The players from the top four teams had a significantly greater standing reach (p=0.038, ES=0.53), were heavier (p=0.032, ES=0.55) but not superior in any fitness measure. Generally hand span, agility and flexibility were not related to performance indicators. It was concluded that shorter and lighter players who possess high levels of speed and endurance are more likely to acquire possessions and be awarded votes, however these attributes do not guarantee team success. The small relationships between agility and flexibility to performance might be explained by the choice of tests used to assess these qualities.

Betaine (BT) supplementation improves selected markers of physical performance, however, the mechanism(s) by which this change occurs remains largely unknown. Some speculate that BT may increase circulating nitrate concentrations, improving physical performance by augmentation of endothelial nitric oxide production. The purpose of this study was to investigate the effects of acute BT supplementation and exercise on plasma nitrate levels and related cardiovascular response (CVR). Placebo and BT trials were administered in a cross-over, randomized, double-blind, and counterbalanced fashion. Ten healthy college-aged volunteers consumed either a 250 ml placebo (carbohydrate-electrolyte beverage, CHO) or 250 ml CHO + 2.5 g BT. Subjects rested for 45 min, then cycled for 30 min at 60 rpm with a resistance of 2.5% body weight. Blood was drawn before and 45 min after BT supplementation, and immediately post exercise to assess plasma nitrate levels. Repeated measures ANOVA across treatments and times assessed differences in plasma nitrate and CVR variables with an alpha level set at 0.05. No significant interactions nor differences between groups were found for plasma nitrate levels or CVR variables with acute BT supplementation. A significant time effect (p < 0.013) for all CVR variables was found and expected due to the effect of exercise. Acute BT supplementation did not increase plasma nitrate levels nor alter CVR at rest or during light to moderate cycling.

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