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This study sought to describe head impact exposure in women's collegiate club lacrosse. Eleven women's collegiate club lacrosse players wore head impact sensors during eight intercollegiate competitions. Video recordings of competitions were used to verify impact data. Athletes completed questionnaires detailing their concussion history and perceived head impact exposure. During the monitored games, no diagnosed concussions were sustained. Three athletes reported sustaining head impacts (median = 0; range: 0-3 impacts per game). Six impacts registered by the sensors were verified on video across a total of 81 athlete-game exposures. Verified impacts had a median peak linear acceleration of 21.0 g (range: 18.3 g - 48.3 g) and peak rotational acceleration of 1.1 krad/s

Individuals with anxiety disorders exhibit lower intrinsic functional connectivity between prefrontal cortical areas and subcortical regions. The prefrontal cortex (PFC) is sensitive to the acute and chronic effects of physical activity (PA), while the anxiolytic effects of PA are well known. The current study examined the association of generalized anxiety disorder (GAD) and its interaction with PA, with resting-state, left PFC oxygenation. This cross-sectional study used data from participants (N = 2444) from The Irish Longitudinal Study on Ageing, a nationally representative prospective study of community-living adults aged 50 and older in Ireland. The Composite International Diagnostic Interview Short-Form determined fulfillment of criteria for GAD. The short-form International Physical Activity Questionnaire determined adherence to the World Health Organization PA guidelines. Resting-state, left PFC oxygenation was continuously measured via a Portalite. Tissue saturation index (TSI) was calculated as the ratio of oxygenated hemoglobin to total tissue hemoglobin (expressed as a percentage) for the final minute of a 5-minute supine-rest period. Multivariable linear regression quantified associations of GAD with TSI in the total population and population stratified by PA status. Participants with GAD had lower TSI (b = −1.416, p = .008) compared to those without GAD. However, this association was modified by PA. Among participants who met the PA guidelines, TSI did not differ according to GAD status (b = −0.800, p = .398). For participants who did not meet the guidelines, TSI was significantly lower among those with GAD (b = −1.758, p = .004). These findings suggest that PA may help to protect brain health among older adults with GAD.

The SIM-G is a waterproof head impact sensor that has been previously evaluated for use in a headband, but not yet in a mode of attachment suitable for water polo. For this study, a CADEX linear impactor was used to impact a Hybrid III headform while wearing either a headband or modified water polo cap, each housing a SIM-G. In both headgears, the SIM-G consistently underestimated peak linear acceleration ( p .198). The proprietary SIM-G algorithm used for classifying false/true positives performed poorly at the back and crown impact locations in both the water polo cap and headband, but accuracy of this algorithm did not significantly differ between the water polo cap and headband (60.5% vs 49.4%, respectively). The SIM-G’s ability to correctly predict impact location also performed poorly in both headgears when impacts occurred at the crown location, but was significantly better overall in the water polo cap than the headband (80.2% vs 55.6%, respectively). These results demonstrate that the SIM-G exhibits shared limitations and a similar performance overall when placed in either a headband or water polo cap. Potential explanations for the inaccuracies of the SIM-G, as well as methods of optimizing its application in sports, are discussed.

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.

A growing body of evidence suggests that chronic, sport-related head impact exposure can impair brain functional integration and brain structure and function. Evidence of a robust inverse relationship between the frequency and magnitude of repeated head impacts and disturbed brain network function is needed to strengthen an argument for causality. In pursuing such a relationship, we used cap-worn inertial sensors to measure the frequency and magnitude of head impacts sustained by eighteen intercollegiate water polo athletes monitored over a single season of play. Participants were evaluated before and after the season using computerized cognitive tests of inhibitory control and resting electroencephalography. Greater head impact exposure was associated with increased phase synchrony [r(16) > 0.626, p < 0.03 corrected], global efficiency [r(16) > 0.601, p < 0.04 corrected], and mean clustering coefficient [r(16) > 0.625, p < 0.03 corrected] in the functional networks formed by slow-wave (delta, theta) oscillations. Head impact exposure was not associated with changes in performance on the inhibitory control tasks. However, those with the greatest impact exposure showed an association between changes in resting-state connectivity and a dissociation between performance on the tasks after the season [r(16) = 0.481, p = 0.043] that could also be attributed to increased slow-wave synchrony [F(4, 135) = 113.546, p < 0.001]. Collectively, our results suggest that athletes sustaining the greatest head impact exposure exhibited changes in whole-brain functional connectivity that were associated with altered information processing and inhibitory control.

Objectives Recent reports have demonstrated a risk of concussion and subconcussive head impacts in collegiate varsity and international elite water polo. We sought to characterize patterns of head impact exposure at the collegiate club level of water polo. Design Prospective cohort study. Methods Head impact sensors (SIM-G, Triax Technologies) were worn by men’s (n = 16) and women’s (n = 15) collegiate club water polo players during 11 games. Peak linear acceleration (PLA) and peak rotational acceleration (PRA) of head impacts were recorded by the sensors. Two streams of competition video were used to verify and describe the nature of head impacts. Results Men’s players sustained 52 verified head impacts of magnitude 39.7 ± 16.3 g PLA and 5.2 ± 3.2 krad/s2 PRA, and women’s players sustained 43 verified head impacts of magnitude 33.7 ± 12.6 g PLA and 4.0 ± 2.8 krad/s2 PRA. Impacts sustained by men had greater PLA than those sustained by women (p = .045). Athletes were impacted most frequently at the offensive center position, to the back of the head, and by an opponent’s torso or limb. Conclusions Our cohort of male and female athletes sustained relatively infrequent head impacts during water polo competitions played at the collegiate club level. The amount of head impact exposure in our cohort was dependent on player position, with offensive centers prone to sustaining the most impacts. Head impact sensors are subject to large amounts of false positives and should be used in conjunction with video recordings to verify the validity of impact data.

Concussive and subconcussive sports-related head impacts are common in the United States, particularly in American football. Football helmets are constantly improving upon their predecessors and are proven to reduce head impact kinematics and the risk of sports-related head injury. All football helmets are required to pass certification testing overseen by the National Operating Committee on Standards for Athletic Equipment (NOCSAE) before they are permitted for use. A new advance in protective equipment involves coupling a helmet and shoulder pads as one connected piece of protective equipment. These protective gears cannot be tested using the standard NOCSAE method as they are worn over a user’s head, neck, and upper torso. We aimed to test the effectiveness of a prototype of a coupled, one-piece design, relative to a standard football helmet, using a custom drop tower method of testing. Relative to the standard football helmet, the coupled design reduced measures of peak linear acceleration at front, side, and rear impacts (p

Recent reports have demonstrated that there is a serious risk of head impact and injury in water polo. The use of protective headgear in contact sports is a commonly accepted strategy for reducing the risk of head injury, but there are few available protective headgears for use in water polo. Many of those that are available are banned by the sport's governing bodies due to a lack of published data supporting the effectiveness of those headgears in reducing head impact kinematics. To address this gap in knowledge, we launched a water polo ball at the forehead of an anthropomorphic testing device fitted with either a standard water polo headgear or one of two protective headgears. We selected a range of launch speeds representative of those observed across various athlete ages. Mixed-model ANOVAs revealed that, relative to standard headgear, protective headgears reduced peak linear acceleration (by 10.8-21.6%; p < 0.001), and peak rotational acceleration (by 24.5-48.5%; p < 0.001) induced by the simulated ball-to-forehead impacts. We discuss the possibility of using protective headgears in water polo to attenuate head impact kinematics.

The benefits of exercise for smokers attempting to quit are partially dependent on physical activity levels prior to cessation. Mood disturbances can manifest within 30 min of smoking a cigarette and contribute to negative reinforcement of smoking behavior over time, whereas a single bout of aerobic exercise can reduce negative mood states and improve affect on a similar timescale in non-smokers. The acute effects of exercise among non-abstaining smokers immediately after a cigarette are unknown but may have clinical implications for smokers considering cessation. The aim of this study was to examine the concurrent effects of exercise on mood disturbance and prefrontal brain hemodynamic response to emotionally arousing scenes 30 min after smoking a cigarette and to test whether prefrontal brain hemodynamic response was correlated with affective ratings of the scenes. Fifteen cigarette smokers, averaging 47.6 cigarettes/week in the year prior to screening, served as participants. Functional near-infrared spectroscopy was used to measure hemodynamic status over the dorsolateral prefrontal cortex (DLPFC). Participants viewed pleasant, unpleasant, and neutral scenes prior to smoking a cigarette and 30 min later after seated rest or exercise at a preferred intensity. Mood disturbance was assessed by the Profile of Mood States-Brief Form four times: before smoking a cigarette, before and after exercise and rest, and after a post-condition (exercise/rest) exposure to emotionally arousing scenes. Compared to seated rest, cycling after a cigarette reduced mood disturbance (p = =.038) and DLPFC hemodynamic response to unpleasant (p = =.003) and pleasant (p = =.021) scenes relative to neutral scenes. DLPFC hemodynamic response was not related to affective ratings of scenes. We report that cycling for 20 min at a preferred intensity reduces mood disturbances which occur shortly after smoking a cigarette and blunts DLPFC hemodynamic response to emotionally arousing scenes. The findings encourage further investigation of exercise for smokers in the maintenance stage of smoking cessation.

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/sec2) 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/sec2) and practices (means ± SD: 0.96±1.11 hits/practice, PLA = 43.7±14.5g, PRA = 3.9±2.5 krads/sec2). 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.

ObjectivesReturn-to-play protocols could be improved by a better understanding of the physiologic effects of mild traumatic brain injury (mTBI). Autonomic dysregulation is thought to underlie many of the multi-dimensional symptoms following mTBI and may derive from altered connectivity in the brain central autonomic network (CAN). Understanding the relationship between injury and CAN connectivity could lead to a useful biomarker for mTBI. Toward this end, the present study aimed to establish a formal relationship between non-symptomatic head-to-ball impacts (“headers”) and CAN connectivity in collegiate soccer athletes.MethodsEleven male NCAA Division I soccer players were monitored by athletic training staff throughout 1 season for the number of headers. Ten male NCAA Division I athletes (3 cross-country and 7 golfers) served as controls. All participants underwent resting-state fMRI pre- and post-season. Twenty ROIs were selected based on regions previously implicated in control and modulation of autonomic function. Graph theoretical analyses were used to probe changes in network architecture and connectivity. Specific contrasts focused on pre- and post-season changes that were explained by individual differences in exposure to headers (p < 0.05 uncorrected).ResultsWithin the 20 node network, increases in headers were associated with reduced degree centrality of the left and right insular cortex and right putamen (p< 0.02), increased degree and betweenness centrality in the left anterior and right posterior Para hippocampal gyri (p< 0.03), and increased betweenness centrality in the anterior cingulate cortex (p = 0.006). Headers were also associated with reduced functional connectivity within the subnetwork including the anterior cingulate cortex (p = 0.0073), right hippocampus, left putamen, and left insular cortex (p< 0.04).ConclusionHighly skilled soccer players who sustained the greatest number of head impacts also experienced the greatest altered connectivity among regions associated with autonomic function. Future work to establish autonomic function as an injury biomarker should consider the importance of cumulative impact magnitudes.

Feelings of fatigue are reduced after a session of continuous exercise of low-to-moderate intensity lasting 20 min or more, but only when feelings of energy are increased. Feelings of fatigue and energy have not been described after fatiguing, high-intensity interval exercise. Cerebral oxygenation has been implicated as a central correlate of fatigability, but it has not been studied concurrent with perceived fatigue during or after exercise.Fifteen recreationally active participants (8 women, 7 men) completed bouts of sprint interval cycling (four, 30-s all-out sprints each followed by 4 min of active recovery) and a time- and work-matched bout of constant resistance cycling. Oxygenation (oxygenated hemoglobin [HbO2]) and deoxygenation (deoxygenated hemoglobin [HHb]) in the dorsolateral prefrontal cortex were measured using near-infrared spectroscopy. Fatigue ratings during each sprint and feelings of fatigue and energy during recovery were assessed.Increases in HbO2 and HHb in frontal cortex were greater during sprint cycling than during constant resistance cycling (P = 0.001). Fatigability (decreased power output) increased over successive sprints (P = 0.001). About 95% of the increase in fatigue ratings across sprints (P0.001) was accounted for by fatigability and cortical HbO2. Feelings of fatigue were decreased (P0.001) and feelings of energy were increased (P0.05) across sprint recovery periods but were unchanged during constant resistance cycling. About 85% of the changes in feelings of fatigue or energy during recovery were explained by fatigue ratings across sprints and maximum HbO2 in the cortex during recovery.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.

We evaluated levels of exercise-induced brain-derived neurotrophic factor (BDNF) messenger RNA (mRNA) within the hippocampal formation in rats selectively bred for 1) high intrinsic (i.e., untrained) aerobic capacity (High Capacity Runners, HCR), 2) low intrinsic aerobic capacity (Low Capacity Runners, LCR), and 3) unselected Sprague–Dawley (SD) rats with or without free access to running wheels for 3 weeks. The specific aim of the study was to determine whether a dose–response relationship exists between cumulative running distance and levels of BDNF mRNA. No additional treatments or behavioral manipulations were used. HCR, LCR, and SD rats were grouped by strain and randomly assigned to sedentary or activity (voluntary access to activity wheel) conditions. Animals were killed after 21 days of exposure to the assigned conditions. Daily running distances (mean ± standard deviation meters/day) during week three were: HCR (4726 ± 3220), SD (2293 ± 3461), LCR (672 ± 323). Regardless of strain, levels of BDNF mRNA in CA1 were elevated in wheel runners compared to sedentary rats and this difference persisted after adjustment for age (p = 0.040). BDNF mRNA was not affected by intrinsic aerobic capacity and was not related to total running distance. The results support that BDNF mRNA expression is increased by unlimited access to activity wheel running for 3 weeks but is not dependent upon accumulated running distance.