Repeated, high-intensity sprints were fatiguing, but paradoxical reductions in feelings of fatigue and increases in feelings of energy occurred during recovery that were accounted for by ratings of fatigue during exercise and oxygenation in the dorsolateral prefrontal cortex during recovery.

Water polo is a contact sport that is gaining popularity in the United States and carries a risk of repeated head impacts and concussion. The frequency and magnitude of sport-related head impacts have not been described for water polo. We aimed to compare patterns of empirically measured head impact exposure of male collegiate water polo players to patterns previously reported by a survey of current and former water polo athletes. Participants wore water polo caps instrumented with head impact sensors during three seasons of collegiate water polo. Peak linear acceleration (PLA) and peak rotational acceleration (PRA) were recorded for head impacts. Athlete positions were recorded by research staff at the occurrence of each head impact. Head impacts were sustained by athletes in offensive positions more frequently than in defensive and transition positions (246, 59.9% vs. 93, 22.6% vs. 72, 17.5%). 37% of all head impacts during gameplay were sustained by athletes playing the offensive center position. Impact magnitude (means ± SD: PLA = 36.1±12.3g, PRA = 5.0±2.9 krads/sec 2 ) did not differ between position or game scenario. Among goalies, impact frequency and magnitude were similar between games (means ± SD: 0.54±.51 hits/game, PLA = 36.9±14.2g, PRA = 4.3±4.2 krads/sec 2 ) and practices (means ± SD: 0.96±1.11 hits/practice, PLA = 43.7±14.5g, PRA = 3.9±2.5 krads/sec 2 ). We report that collegiate water polo athletes are at risk for sport-related head impacts and impact frequency is dependent on game scenario and player position. In contrast, magnitude does not differ between scenarios or across positions.

Recent findings support positive effects of acute aerobic exercise on worry, state anxiety, and feelings of energy and fatigue among young adult women with subclinical, or analogue, generalized anxiety disorder (GAD). However, exercise effects among young adult men with analogue GAD are unstudied. Purpose: This study replicated initial findings of positive effects of acute vigorous-intensity aerobic exercise on worry, state anxiety, and feelings of energy and fatigue among young adult women with analogue GAD, examined responses among young adult men with analogue GAD, and explored sex-related differences and moderation by physical activity level, trait anxiety, depression, and poor sleep status. Methods: Thirty-five young adults (21.4 ± 2.3 yr; 19 males; 16 females) with Penn State Worry Questionnaire scores ≥45 (60 ± 8) completed two counterbalanced 30-min conditions: treadmill running at ~71.2% ± 0.04% HR reserve and seated quiet rest. Outcomes included worry, worry engagement, absence of worry, state anxiety, and feelings of energy and fatigue. Results: No outcome or moderator differed at baseline between sexes. Exercise significantly improved state anxiety (P < 0.04; d = 0.27) and feelings of energy (P < 0.001; d = 1.09). Small nonsignificant improvements were found for worry (d = 0.22), worry engagement (d = 0.18), and feelings of fatigue (d = 0.21). The magnitude of improvements in worry, worry engagement, absence of worry, and feelings of energy were stronger among females. Significant large, potentially clinically meaningful increases in feelings of energy were found among women (d =

Heart rate variability (HRV) provides insight into cardiovascular health and autonomic function. Electrocardiography (ECG) provides gold standard HRV measurements but is inconvenient for continuous acquisition when monitored from the extremities. Optical techniques such as photoplethysmography (PPG), often found in health and wellness trackers for heart rate measurements, have been used to estimate HRV peripherally but decline in accuracy during increased physical stress. Speckleplethysmography (SPG) is a recently introduced optical technique that provides benefits over PPG, such as increased signal amplitude and reduced susceptibility to temperature-induced vasoconstriction. In this research, we compare SPG and PPG to ECG for estimation of HRV during an orthostatic challenge performed by 17 subjects. We find that SPG estimations of HRV are highly correlated to ECG HRV for both time and frequency domain parameters and provide increased accuracy over PPG estimations of HRV. The results suggest SPG measurements are a viable alternative for HRV estimation when ECG measurements are impractical.

Mammals' affinity for sweet tastes exists alongside dramatic variation among species and individuals in responses to sweeteners. The present paper focused on consumption by Occidental High- (HiS) and Low-Saccharin (LoS)-consuming rats in 23-h 2-bottle tests of 2 sweeteners for which few data from rats are available: SC45647 and sucralose. Every HiS and LoS rat preferred SC45647 to water at every concentration, with HiS rats consuming it more avidly. Most HiS rats preferred sucralose to water at one or more concentrations; some HiS rats and most LoS rats avoided sucralose at every concentration. However, both HiS and LoS rats preferred a sucralose-maltodextrin mixture (Splenda) to water; thus, Splenda's "bulking" ingredient maltodextrin transforms highly variable responses to sucralose into a relatively homogeneous preference for the product. Implications for the study of variation in sweet taste are discussed.