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Importance: An objective, reliable indicator of the presence and severity of concussive brain injury and of the readiness for the return to activity has the potential to reduce concussion-related disability., Objective: To validate the classification accuracy of a previously derived, machine learning, multimodal, brain electrical activity-based Concussion Index in an independent cohort of athletes with concussion., Design, Setting, and Participants: This prospective diagnostic cohort study was conducted at 10 clinical sites (ie, US universities and high schools) between February 4, 2017, and March 20, 2019. A cohort comprising a consecutive sample of 207 athletes aged 13 to 25 years with concussion and 373 matched athlete controls without concussion were assessed with electroencephalography, cognitive testing, and symptom inventories within 72 hours of injury, at return to play, and 45 days after return to play. Variables from the multimodal assessment were used to generate a Concussion Index at each time point. Athletes with concussion had experienced a witnessed head impact, were removed from play for 5 days or more, and had an initial Glasgow Coma Scale score of 13 to 15. Participants were excluded for known neurologic disease or history within the last year of traumatic brain injury. Athlete controls were matched to athletes with concussion for age, sex, and type of sport played., Main Outcomes and Measures: Classification accuracy of the Concussion Index at time of injury using a prespecified cutoff of 70 or less (total range, 0-100, where ≤70 indicates it is likely the individual has a concussion and >70 indicates it is likely the individual does not have a concussion)., Results: Of 580 eligible participants with analyzable data, 207 had concussion (124 male participants [59.9%]; mean [SD] age, 19.4 [2.5] years), and 373 were athlete controls (187 male participants [50.1%]; mean [SD] age, 19.6 [2.2] years). The Concussion Index had a sensitivity of 86.0% (95% CI, 80.5%-90.4%), specificity of 70.8% (95% CI, 65.9%-75.4%), negative predictive value of 90.1% (95% CI, 86.1%-93.3%), positive predictive value of 62.0% (95% CI, 56.1%-67.7%), and area under receiver operator characteristic curve of 0.89. At day 0, the mean (SD) Concussion Index among athletes with concussion was significantly lower than among athletes without concussion (75.0 [14.0] vs 32.7 [27.2]; P < .001). Among athletes with concussion, there was a significant increase in the Concussion Index between day 0 and return to play, with a mean (SD) paired difference between these time points of -41.2 (27.0) (P < .001)., Conclusions and Relevance: These results suggest that the multimodal brain activity-based Concussion Index has high classification accuracy for identification of the likelihood of concussion at time of injury and may be associated with the return to control values at the time of recovery. The Concussion Index has the potential to aid in the clinical diagnosis of concussion and in the assessment of athletes' readiness to return to play.

Huggins, RA, Giersch, GEW, Belval, LN, Benjamin, CL, Curtis, RM, Sekiguchi, Y, Peltonen, J, and Casa, DJ. The validity and reliability of GPS units for measuring distance and velocity during linear and team sport simulated movements. J Strength Cond Res 34(11): 3070-3077, 2020-This experimental study aimed to assess the validity and reliability of shirt-mounted 10-Hz global positioning system (GPS) units (Polar Team Pro) for measuring total distance (TD), constant velocity (VelC), and instantaneous velocity (VelI) during linear running and a team sport simulation circuit (TSSC). Fifteen male soccer athletes completed linear tasks (40 and 100 m) at various velocities: walk (W) (4.8-7.9 km·h), jog (J) (8.0-12.7 km·h), run (R) (12.9-19.9 km·h), and sprint (S) (>20.0 km·h) and a 120-m TSSC. Global positioning system validity and reliability for TD, VelC, and VelI were compared with criterion measures using 2 methods (a and b) of GPS raw data extraction. When measuring TD for the Polar Team Pro device, validity and reliability measures were <5% error at all velocities during the 40-m (with the exception of the S [%CV = 8.03]) and 100-m linear trial (both extraction methods) and TSSC. The GPS mean difference (±SD) for TD during the TSSC using extraction methods (a) and (b) was 0.2 ± 1.2 and 2.2 ± 2.2 m, respectively. The validity of the device in measuring VelC was significantly different (p < 0.05) at all velocities during the 40 m (exception W) and the 100 m, with effect sizes ranging from trivial to small (exception of 100 m S). VelI was similar (p > 0.05) at all velocities, except for the W (p = 0.001). The reliability of the device when measuring VelC during the 40 and 100 m was <5% CV; however, during the 100 m, VelI ranged from 1.4 to 12.9%. Despite trivial to large effect sizes for validity of TD, this device demonstrated good reliability <5% CV during linear and TSSC movements. Similarly, effect sizes ranged from trivial to large for VelC, and yet VelI reliability was good for VelC, but good to poor for VelI.

Context: Athletic trainers (ATs) are educated and trained in appropriate exertional heat-stroke (EHS) management strategies, yet disparities may exist between intended and actual uses in clinical practice., Objective: To examine the intended and actual uses of EHS management strategies among those who did and those who did not treat patients with suspected cases of EHS during the 2017 high school (HS) American football preseason., Design: Cross-sectional study., Setting: Online questionnaire., Patients or Other Participants: A total of 1016 ATs who oversaw patient care during the 2017 HS American football preseason., Main Outcome Measure(s): Responding HS ATs recorded whether they had or had not managed patients with suspected EHS events during the 2017 HS American football preseason. Those who had managed patients with suspected cases of EHS reported the management strategies used; those who had not managed such patients described their intended management strategies. For each management strategy, z tests compared the proportions of actual use among ATs who managed patients with suspected EHS with the proportions of intended use among ATs who did not manage such patients., Results: Overall, 124 (12.2%) ATs treated patients with suspected EHS cases during the 2017 HS American football preseason. Generally, the proportions of intended use of management strategies among ATs who did not treat patients with suspected EHS were higher than the actual use of those strategies among ATs who did. For example, ATs who did treat patients with suspected EHS were more likely than those who did not treat such patients to intend to take rectal temperature (19.6% versus 3.2%, P < .001) and immerse the athlete in ice water (90.1% versus 51.6%, P < .001)., Conclusions: Inconsistencies occurred between intended and actual use of EHS management strategies. The standard of care for managing patients with suspected cases of EHS was not consistently used in clinical practice, although ATs who did not treat EHS stated they intended to use these management strategies more frequently. Future researchers should identify factors that preclude ATs from using the standard of care when treating patients with suspected cases of EHS., (© by the National Athletic Trainers' Association, Inc.)

Context : Recent data on exertional heat illness (EHI) in high school sports are limited yet warranted to identify specific settings with the highest risk of EHI. Objective : To describe the epidemiology of EHI in high school sports during the 2012/2013-2016/2017 academic years. Design: Descriptive epidemiology study. Setting : Aggregate injury and exposure data collected from athletic trainers working in high school sports in the United States. Patients or Other Participants : High school athletes during the 2012/2013-2016/2017 academic years. Intervention : High School Reporting Information Online surveillance system data from the 2012/2013-2016/2017 academic years were analyzed. Main Outcome Measures : EHI counts, rates per 10,000 athlete exposures (AEs), and distributions were examined by sport, event type, and US census region. EHI management strategies provided by athletic trainers were analyzed. Injury rate ratios with 95% confidence intervals (CIs) compared EHI rates. Results : Overall, 300 EHIs were reported for an overall rate of 0.13/10,000 AE (95% CI, 0.11 to 0.14). Of these, 44.3% occurred in American football preseason practices; 20.7% occurred in American football preseason practices with a registered air temperature ≥90°F and ≥1 hour into practice. The EHI rate was higher in American football than all other sports (0.52 vs 0.04/10,000 AE; injury rate ratio = 11.87; 95% CI, 9.22 to 15.27). However, girls' cross-country had the highest competition EHI rate (1.18/10,000 AE). The EHI rate was higher in the South US census region than all other US census regions (0.23 vs 0.08/10,000 AE; injury rate ratio = 2.96; 95% CI, 2.35 to 3.74). Common EHI management strategies included having medical staff on-site at the onset of EHI (92.7%), removing athlete from play (85.0%), and giving athlete fluids via the mouth (77.7%). Conclusions : American football continues to have the highest overall EHI rate although the high competition EHI rate in girls' cross-country merits additional examination. Regional differences in EHI incidence, coupled with sport-specific variations in management, may highlight the need for region- and sport-specific EHI prevention guidelines.

Curtis, RM, Huggins, RA, Benjamin, CL, Sekiguchi, Y, Adams, WM, Arent, SM, Jain, R, Miller, SJ, Walker, AJ, and Casa, DJ. Contextual factors influencing external and internal training loads in collegiate men's soccer. J Strength Cond Res 34(2): 374-381, 2020-This study investigated factors influencing training loads (TL) in collegiate men's soccer. Total distance, high-speed running distance (>14.4 km·h), high-intensity heart-rate zone duration (HI HRZ, >70% heart rate relative to maximum), and session rating of perceived exertion were assessed daily from 107 male soccer players competing for 5 National Collegiate Athletics Association Division I teams. Differences between athlete role (starter and reserve), position (defender, midfielder, and forward), season phase (preseason, in-season, and postseason), days relative to match (MD-1 to MD-5+), days between matches (<4, 4-5, >5 days), previous match outcome (win, loss, and draw), and upcoming opponent relative ranking (weaker, trivial, and stronger) were examined. Mean differences (MD) and effect sizes (ESs) with 90% confidence intervals were reported. There were trivial and insignificant differences by player role, position, or upcoming opponent strength, and small-moderate increases in preseason TL compared with in-season (ES [range] = 0.4-0.9). TLs were lower for MD-1 and higher for MD-5+ (ES [range] = 0.4-1.3) when compared with MD-2-4. External loads (ES = -0.40 ± 0.20) were less after wins compared with losses. TLs are increased in the preseason, when training sessions occur greater than 5 days from a match and after losses. Contextualizing factors affecting TLs has implications for developing workload prescription and recovery strategies.

Clinical Scenario: Exercise in the heat can lead to performance decrements and increase the risk of heat illness. Heat acclimation refers to the systematic and gradual increase in exercise in a controlled, laboratory environment. Increased duration and intensity of exercise in the heat positively affects physiological responses, such as higher sweat rate, plasma volume expansion, decreased heart rate, and lower internal body temperature. Many heat acclimation studies have examined the hydration status of the subjects exercising in the heat. Some of the physiological responses that are desired to elicit heat acclimation (ie, higher heart rate and internal body temperature) are exacerbated in a dehydrated state. Thus, euhydration (optimal hydration) and dehydration trials during heat acclimation induction have been conducted to determine if there are additional benefits to dehydrated exercise trials on physiological adaptations. However, there is still much debate over hydration status and its effect on heat acclimation. Clinical Question: Does dehydration affect the adaptations of plasma volume, heart rate, internal body temperature, skin temperature, and sweat rate during the induction phase of heat acclimation? Summary of Findings: There were no observed differences in plasma volume, internal body temperature, and skin temperature following heat acclimation in this critically appraised topic. One study found an increase in sweat rate and another study indicated greater changes in heart rate following heat acclimation with dehydration. Aside from these findings, all 4 trials did not observe statistically significant differences in euhydrated and dehydrated heat acclimation trials. Clinical Bottom Line: There is minimal evidence to suggest that hydration status affects heat acclimation induction. In the studies that met the inclusion criteria, there were no differences in plasma volume concentrations, internal body temperature, and skin temperature. Strength of Recommendation: Based on the Oxford Centre for Evidence-Based Medicine Scale, Level 2 evidence exists.

Even though sleep has been shown to be influenced by athletes' training status, the association with resting heart rate and heart rate variability remains unclear. The purpose of this study was to compare the changes in and relationships between resting heart rate, heart rate variability and sleep characteristics across a female collegiate cross-country season. Ten NCAA Division I collegiate female cross-country athletes (mean ± SD; age, 19 ± 1 year; height, 167.6 ± 7.6 cm; body mass, 57.7 ± 10.2 kg; VO 2max , 53.3 ± 5.9 ml kg -1  min -1 ) participated in this study. Resting heart rate, heart rate variability and the percentage of time in slow wave sleep were captured using a wrist-worn multisensor sleep device throughout the 2016 competitive cross-country season (12 weeks). Linear mixed-effects models and magnitude-based inferences were used to assess differences between each week. Pearson product moment correlations were used to investigate relationships between variables. Resting heart rate at the end of the season, specifically during weeks 10-12 (mean ± SE; week 10, 48 ± 2; week 11, 48 ± 3; week 12, 48 ± 3), showed a practically meaningful increase compared to the beginning of the season, weeks 2-4 (week 2, 44 ± 2; week 3, 45 ± 2; week 4, 44 ± 2). Higher resting heart rate (r = 0.55) and lower heart rate variability (r = -0.62) were largely associated with an increase in percentage of time spent in slow wave sleep. These data suggest that when physiological state was impaired, meaning the physiological restorative demand was higher, the percentage of time in slow wave sleep was increased to ensure recovery. Thus, it is important to implement sleep hygiene strategies to promote adequate slow wave sleep when the body needs physiological restoration., (© 2019 European Sleep Research Society.)

Context: In 2009, the National Athletic Trainers' Association Inter-Association Task Force (NATA-IATF) released preseason heat-acclimatization guidelines for gradually acclimatizing high school (HS) athletes to the environment during the first 2 weeks of the preseason and reducing the risk of exertional heat illness. However, researchers who studied the 2011 preseason found a low level of overall compliance., Objective: To assess compliance with the NATA-IATF guidelines during the 2017 preseason and compare the findings with 2011 preseason data and between states mandating and not mandating the guidelines., Design: Cross-sectional study., Setting: Preseason HS football, 2017., Patients or Other Participants: A total of 1023 athletic trainers working with HS football (14.2% response rate)., Main Outcome Measure(s): Using a survey, we acquired information from athletic trainers on their HS football programs, including location and compliance with 17 NATA-IATF guidelines during the 2017 football preseason. The outcome measures were full compliance with all 17 NATA-IATF guidelines and compliance with ≥10 NATA-IATF guidelines. Prevalence ratios (PRs) with 95% confidence intervals (CIs) compared findings between (1) the 2017 and 2011 preseasons and (2) states whose HS athletic associations imposed a full or partial or no mandate to follow the NATA-IATF guidelines., Results: Overall, 3.9% reported full compliance with NATA-IATF guidelines; 73.9% complied with ≥10 guidelines. The proportion reporting full compliance was higher in 2017 than in 2011 but not statistically different (3.9% versus 2.5%; PR = 1.54; 95% CI = 0.96, 2.46). However, the proportion reporting compliance with ≥10 guidelines was higher in 2017 (73.9% versus 57.9%; PR = 1.28; 95% CI = 1.20, 1.36). The proportion of respondents reporting their HSs were fully compliant was highest among the with-mandate group (9.4%), followed by the partial-mandate group (4.6%) and the without-mandate group (0.6%). Group differences retained significance when we examined compliance with ≥10 guidelines., Conclusions: Although full compliance with NATA-IATF guidelines remained low, many HS football programs complied with ≥10 guidelines.

Context: Sudden death in sport at the high school and collegiate levels has been described extensively in the literature. However, few epidemiologic data exist on the incidence of sudden death specifically in American youth sport before secondary school athletics., Objective: To describe the epidemiology of sudden death in organized youth sports in the United States from 2007 through 2015., Design: Descriptive epidemiology study., Setting: Organized American youth sports., Patients or Other Participants: Cases of sudden death that occurred in youth athletes 17 years of age and younger in non-high school organized sports were included., Data Collection and Analysis: Information on sudden deaths between August 1, 2007, and December 31, 2015, was obtained via LexisNexis and other publicly available news or media reports. Total youth sport participation rates from 2007 to 2015 were provided by the Sport & Fitness Industry Association. Athlete age, sex, sport, level of play, event type, date of death, setting, and official and speculated causes of death were examined. Data are presented as deaths per year, percentage of total sudden deaths, and deaths per 10 million participants., Results: From 2007 to 2015, 45 sudden deaths were reported in American youth sports. The mean age of patients was 13 ± 2 years. The overall incidence rate was 1.83 deaths/10 million athlete-years. Males experienced a greater number of sudden deaths than females (n = 36/45, 80%). Basketball had the highest number of sudden deaths from 2007 to 2015, with a total of 16 occurrences. The most frequent cause of sudden death was cardiac related (n = 34/45, 76%). Most sudden deaths occurred during practices (n = 32/45, 71%)., Conclusions: Sudden deaths in organized youth sports in the United States from 2007 through 2015 were most often experienced during practices by males, were cardiac related, and occurred while playing basketball. These findings are similar to those in high school and collegiate sports. This study affirms the need for further epidemiologic research into sudden deaths at the organized youth sport level.

Background: The risk of heat-related illness and death may continue to increase in many locations as a consequence of climate change, but information on the effectiveness of policies to protect populations from the adverse effects of excessive heat is limited. In 2009, the National Athletic Trainers' Association Inter-Association Task Force (NATA-IATF) released guidelines to reduce exertional heat illness (EHI) among U.S. high school athletes participating in preseason sports activities, including preseason practice sessions for American football. A subset of state high school athletic associations have implemented state-mandated guidelines consistent with the 2009 NATA-IATF recommendations, but their effectiveness for reducing preseason EHI is unknown., Objectives: This study examines the association between the enactment of state high school athletic association-mandated NATA-IATF guidelines and the rate of EHI among high school students during preseason American football practice sessions., Methods: We performed a quasi-experimental interrupted time-series study of EHI during high school American football practices in the 2005/2006-2016/2017 school years. We estimated state-level EHI rates using High School Reporting Information Online injury and athlete-exposure data, and used generalized estimating equations Poisson regression models to estimate incidence rate ratios (IRRs) and 95% confidence intervals (CIs) comparing state-years with and without mandated NATA-IATF guidelines. State-level covariates included state-year-specific average August temperatures, yearly deviations from each state's August average temperature across the study period, and school year., Results: Data were available for 455 state-years from 48 states, including 32 state-years (7.0%) from 8 states when mandated guidelines consistent with the NATA-IATF recommendations were implemented. During an estimated 2,697,089 athlete-exposures, 190 EHIs were reported. Estimated preseason EHI rates were lower during state-years with versus without mandated guidelines (adjusted [Formula: see text], 95% CI: 0.23, 0.87)., Conclusions: Our findings suggest that high school athletes would benefit from enactment of the 2009 NATA-IATF guidelines. Similar analyses of the effectiveness of other public health policies to reduce adverse health effects from ambient heat are warranted. https://doi.org/10.1289/EHP4163.

The International Association of Athletics Federations recognizes the importance of nutritional practices in optimizing an Athlete's well-being and performance. Although Athletics encompasses a diverse range of track-and-field events with different performance determinants, there are common goals around nutritional support for adaptation to training, optimal performance for key events, and reducing the risk of injury and illness. Periodized guidelines can be provided for the appropriate type, amount, and timing of intake of food and fluids to promote optimal health and performance across different scenarios of training and competition. Some Athletes are at risk of relative energy deficiency in sport arising from a mismatch between energy intake and exercise energy expenditure. Competition nutrition strategies may involve pre-event, within-event, and between-event eating to address requirements for carbohydrate and fluid replacement. Although a "food first" policy should underpin an Athlete's nutrition plan, there may be occasions for the judicious use of medical supplements to address nutrient deficiencies or sports foods that help the athlete to meet nutritional goals when it is impractical to eat food. Evidence-based supplements include caffeine, bicarbonate, beta-alanine, nitrate, and creatine; however, their value is specific to the characteristics of the event. Special considerations are needed for travel, challenging environments (e.g., heat and altitude); special populations (e.g., females, young and masters athletes); and restricted dietary choice (e.g., vegetarian). Ideally, each Athlete should develop a personalized, periodized, and practical nutrition plan via collaboration with their coach and accredited sports nutrition experts, to optimize their performance.

Biomarker discovery and validation is a critical aim of the medical and scientific community. Research into exercise and diet-related biomarkers aims to improve health, performance, and recovery in military personnel, athletes, and lay persons. Exercise physiology research has identified individual biomarkers for assessing health, performance, and recovery during exercise training. However, there are few recommendations for biomarker panels for tracking changes in individuals participating in physical activity and exercise training programs. Our approach was to review the current literature and recommend a collection of validated biomarkers in key categories of health, performance, and recovery that could be used for this purpose. We determined that a comprehensive performance set of biomarkers should include key markers of (a) nutrition and metabolic health, (b) hydration status, (c) muscle status, (d) endurance performance, (e) injury status and risk, and (f) inflammation. Our review will help coaches, clinical sport professionals, researchers, and athletes better understand how to comprehensively monitor physiologic changes, as they design training cycles that elicit maximal improvements in performance while minimizing overtraining and injury risk.

Introduction: Exertional hyponatremia (EH) during prolonged exercise involves all avenues of fluid-electrolyte gain and loss. Although previous research implicates retention of excess fluid, EH may involve either loss, gain, or no change of body mass. Thus, the etiology, predisposing factors, and recommendations for prevention are vague-except for advice to avoid excessive drinking., Purpose: This retrospective field study presents case reports of two unacquainted recreational cyclists (LC, 31y and AM, 39 years) who began exercise with normal serum electrolytes but finished a summer 164-km ride (ambient, 34±5°C) with a serum [Na+] of 130 mmol/L., Methods: To clarify the etiology of EH, their pre- and post-exercise measurements were compared to a control group (CON) of 31 normonatremic cyclists (mean ± SD; 37±6 years; 141±3 mmol Na+/L)., Results: Anthropomorphic characteristics, exercise time, and post-exercise ratings of thermal sensation, perceived exertion and muscle cramp were similar for LC, AM and CON. These two hyponatremic cyclists consumed a large and similar volume of fluid (191 and 189 ml/kg), experienced an 11 mmol/L decrease of serum [Na+], reported low thirst sensations; however, LC gained 3.1 kg (+4.3% of body mass) during 8.9 hr of exercise and AM maintained body mass (+0.1kg, +0.1%, 10.6h). In the entire cohort (n = 33), post-event serum [Na+] was strongly correlated with total fluid intake (R 2 = 0.45, p < .0001), and correlated moderately with dietary sodium intake (R 2 =0.28, p = .004) and body mass change (R 2 = 0.22, p = .02). Linear regression analyses predicted the threshold of EH onset (<135 mmol Na+/L) as 168 ml fluid/kg., Conclusions: The wide range of serum [Na+] changes (+6 to -11 mmol/L) led us to recommend an individualized rehydration plan to athletes because the interactions of factors were complex and idiosyncratic.

Heat stroke is one of the top three causes of death for athletes. Vigilance is required to prevent these illnesses and when faced with an individual who is suffering an exertional heat stroke, the goal is to aggressively cool the patient to 102°F within 30 minutes to optimize survival. The elderly are also at risk for heat illness and physicians caring for these patients should discuss prevention and treatment plans.

Context: Prior researchers have examined the first-aid knowledge and decision making among high school coaches, but little is known about their perceived knowledge of exertional heat stroke (EHS) or their relationships with an athletic trainer (AT)., Objective: To examine secondary school football coaches' perceived knowledge of EHS and their professional relationship with an AT., Design: Qualitative study., Setting: Web-based management system., Patients or Other Participants: Thirty-eight secondary school head football coaches (37 men, 1 woman) participated in this study. Their average age was 47 ± 10 years old, and they had 12 ± 9 years' experience as a head football coach., Data Collection and Analysis: Participants responded to a series of online questions that were focused on their perceived knowledge of EHS and professional relationships with ATs. Data credibility was established through multiple-analyst triangulation and peer review. We analyzed the data by borrowing from the principles of a general inductive approach., Results: Two dominant themes emerged from the data: perceived self-confidence of the secondary school coach and the influence of the AT. The first theme highlighted the perceived confidence, due to basic emergency care training, of the coach regarding management of an emergency situation, despite a lack of knowledge. The second theme illustrated the secondary school coach's positive professional relationships with ATs regarding patient care and emergency procedures. Of the coaches who participated, 89% (34 out of 38) indicated positive interactions with their ATs., Conclusions: These secondary school coaches were unaware of the potential causes of EHS or the symptoms associated with EHS, and they had higher perceived levels of self-confidence in management abilities than indicated by their perceived knowledge level. The secondary school football coaches valued and understood the role of the AT regarding patient and emergency care.

The aim of the recent Inter-Association Task Force held in Washington, D.C. at the 2013 Youth Safety Summit determined best practice recommendations for preventing sudden death in secondary school athletics. This document highlights the major health and safety practices and policies in high school athletics that are paramount to keep student athletes safe. The purpose of this commentary is to review the findings of the document developed by the task force and to provide possible areas where research is needed to continue to educate medical practitioners, players, coaches, and parents on ways to prevent tragedies from occurring during sport.

Background: It is estimated that more than 9000 high school athletes are treated for exertional heat illness annually. Risk factors include being obese and beginning practice during hot and humid weather, when athletes are not yet acclimated to physical exertion in heat., Purpose: To describe the epidemiology of exertional heat illness in high school athletes., Methods: National High School Sports-Related Injury Surveillance System data (2005/2006-2010/2011) were analyzed in 2012 to calculate rates and describe circumstances of exertional heat illness., Results: Exertional heat illness occurred at a rate of 1.20 per 100,000 athlete exposures (95% CI=1.12, 1.28). Exertional heat illnesses were widely distributed geographically, and most occurred in August (60.3%). Of the exertional heat illnesses reported during practice, almost one third (32.0%) occurred more than 2 hours into the practice session. The exertional heat illness rate in football (4.42 per 100,000 athlete exposures) was 11.4 times that in all other sports combined (95% CI=8.3, 15.5, p<0.001). In addition, approximately one third (33.6%) of exertional heat illnesses occurred when a medical professional was not onsite at the time of onset., Conclusions: Although most exertional heat illnesses occurred in football, athletes in all sports and all geographic areas are at risk. Because exertional heat illness frequently occurs when medical professionals are not present, it is imperative that high school athletes, coaches, administrators, and parents are trained to identify and respond to it. Implementing effective preventive measures depends on increasing awareness of exertional heat illness and relevant preventive and therapeutic countermeasures., (Copyright © 2013 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.)

Context: Career opportunities for athletic training students (ATSs) have increased substantially over the past few years. However, ATSs commonly appear to be opting for a more diversified professional experience after graduation. With the diversity in available options, an understanding of career decision is imperative., Objective: To use the theoretical framework of socialization to investigate the influential factors behind the postgraduation decisions of senior ATSs., Design: Qualitative study., Setting: Web-based management system and telephone interviews., Patients or Other Participants: Twenty-two ATSs (16 females, 6 males; age = 22 ± 2 years) who graduated in May 2010 from 13 different programs accredited by the Commission on Accreditation of Athletic Training Education., Data Collection and Analysis: All interviews were transcribed verbatim, and the data were analyzed inductively. Data analysis required independent coding by 2 athletic trainers for specific themes. Credibility of the results was confirmed via peer review, methodologic triangulation, and multiple analyst triangulation., Results: Two higher-order themes emerged from the data analysis: persistence in athletic training (AT) and decision to leave AT. Faculty and clinical instructor support, marketability, and professional growth were supporting themes describing persistence in AT. Shift of interest away from AT, lack of respect for the AT profession, compensation, time commitment, and AT as a stepping stone were themes sustaining the reasons that ATSs leave AT. The aforementioned reasons to leave often were discussed collectively, generating a collective undesirable outlook on the AT profession., Conclusions: Our results highlight the importance of faculty support, professional growth, and early socialization into AT. Socialization of pre-AT students could alter retention rates by providing in-depth information about the profession before students commit in their undergraduate education and by helping reduce attrition before entrance into the workforce.

Hyperthermia is common among athletes and in a variety of environments. The purpose of this study was to evaluate the effectiveness of cooling methods on core body temperature, heart rate (HR), and perceptual readings in individuals after exercise. Sixteen subjects (age: 24 ± 6 years, height: 182 ± 7 cm, weight: 74.03 ± 9.17 kg, and body fat: 17.08 ± 6.23%) completed 10 exercise sessions in warm conditions (WBGT: 26.64 ± 4.71°C) followed by body cooling by 10 different methods. Cooling methods included cold water immersion (CWI), shade, Port-a-Cool® (FAN), Emergency Cold Containment System® (ECCS), Rehab. Hood® (HOOD), Game Ready Active Cooling Vest™ (GRV), Nike Ice Vest™ (NIV), ice buckets (IBs), and ice towels (IT). These cooling modes were compared with a control (SUN). Rectal temperature (T(re)), HR, thermal sensation, thirst sensation, and a 56-question Environmental Symptoms Questionnaire (ESQ) were used to assess physiological and perceptual data. Average T(re) after exercise across all trials was 38.73 ± 0.12°C. After 10 minutes of cooling, CWI (-0.65 ± 0.29°C), ECCS (-0.68 ± 0.24°C), and IB (-0.74 ± 0.34°C) had significantly (p < 0.006) greater decreases in T(re) compared with that in SUN (-0.42 ± 0.15°C). The HR after 10 minutes of cooling was significantly (p < 0.006) lower for CWI (82 ± 15 b·min(-1)), ECCS (87 ± 14 b·min(-1)), and IT (84 ± 15 b·min(-1)) when compared with SUN (101 ± 15 b·min(-1)). The thermal sensation between modalities was all significantly (p < 0.006) lower (CWI: 1.5 ± 0.5; Fan: 3.0 ± 1.0; ECCS: 4.5 ± 1.0; Hood: 4.5 ± 0.5; GRV: 4.0 ± 0.5; NIV: 4.5 ± 1.0; IB: 4.0 ± 1.0; IT: 3.0 ± 1.0) when compared with SUN (5.5 ± 0.5), except for Shade (5.0 ± 1.0). There were no significant differences (p > 0.006) in thirst sensation between modalities. The ESQ scores were significantly (p < 0.006) lower for CWI (1 ± 6), Fan (4 ± 5), and IT (3 ± 8) compared with that for SUN (13 ± 12). In conclusion, when athletes experience mild hyperthermia, CWI, ECCS, and IB resulted in a significantly greater decrease in T(re). These cooling strategies are recommended to decrease T(re) during a brief recovery period between exercise bouts.

Concussion or mild traumatic brain injury (mTBI) is a common phenomenon in the United States, with up to 3.6 million sport-related mTBIs diagnosed annually. Return to learn protocols have been developed to facilitate the reintegration of students into school after mTBI, however, the implementation of return to learn protocols varies significantly across geographic regions and school districts. An integrative review of the literature was performed using Whittemore and Knalf's methodology. A search of published literature was conducted using the PRISMA checklist. Database searches were conducted from March 2,019 to October 2,021 using the terms "mild traumatic brain injury" and "return to learn." Twenty-eight publications were included. Three themes were derived from this review: lack of policy, poor staff education on concussion symptoms and stakeholder communication breakdown. The development of communication patterns and use of a return to learn protocol could facilitate a gradual return to full academic workload after concussion.

Context: As the first medical professionals on scene when emergency situations arise in sport, athletic trainers (ATs) need to be proficient in recognizing and managing these conditions. Recent evidence regarding exertional heatstroke indicates a lack of educational training as a factor preventing implementation of best practices, yet other causes of sudden death exist, and little is known about the educational training provided to the AT. Objective: To gain insight into the entry-level AT and athletic training students' (ATSs') perceptions of education received in the area of emergency care techniques. Design: Mixed methods study. Setting: Athletic training programs (ATPs) and practice settings. Patients or Other Participants: Thirteen first-year ATs (n = 7) or recent ATS graduates before employment (n = 6). Data Collection and Analysis: One-on-one phone interviews were conducted and transcribed verbatim. Data were analyzed inductively using a grounded theory approach and open coding. Close-ended questions were analyzed by calculating frequencies, means, and standard deviations. Multiple analyst triangulation and peer review were used to establish data credibility. Results: One main theme emerged: participants revealed they perceived their education to be compartmentalized. Compartmentalization comprised 3 subthemes: cognitive knowledge, skill implementation, and clinical integration. Participants received the cognitive knowledge through traditional teaching methods but had minimal hands-on laboratory practice in the area of basic emergent and immediate care skills. Instructors placed greater focus on situations or cases that educators had encountered versus on the broader scope of conditions. Contrived, discussion-based instructional methods rather than real-life integration were used to evaluate the ATSs' ability to apply the knowledge and skills. Conclusions: Beyond providing ATSs with the necessary didactic knowledge and hands-on practice through structured laboratory sessions, educators must also provide the opportunity for clinical application of knowledge and skills. Athletic training students must be provided opportunities to apply emergent care skills in order to demonstrate competency and critical thinking.

Background: A Venn diagram consisting of percentage body mass loss, urine color, and thirst perception (weight, urine, thirst [WUT]) has been suggested as a practical method to assess hydration status. However, no study to date has examined relationships between WUT and urine hydration indices. Thus, the purpose of this study was to investigate relationships between urine specific gravity, urine osmolality, and the WUT criteria. Hypothesis: Urine specific gravity and urine osmolality indicate hypohydration when the WUT criteria demonstrate hypohydration (≥2 markers). Study Design: Laboratory cohort study. Level of Evidence: Level 3. Methods: A total of 22 women (mean ± SD; age, 20 ± 1 years; mass, 65.4 ± 12.6 kg) and 21 men (age, 21 ± 1 years; body mass, 78.7 ± 14.6 kg) participated in this study. First morning body mass, urine color, urine specific gravity, urine osmolality, and thirst level were collected for 10 consecutive days in a free-living situation. Body mass loss >1%, urine color >5, and thirst level ≥5 were used as the dehydration thresholds. The number of markers that indicated dehydration levels were counted and categorized into either 3, 2, 1, or 0 WUT markers that indicated dehydration. One-way analysis of variance with Tukey pairwise comparisons was used to assess the differences in urine specific gravity and urine osmolality between the different number of WUT markers. Results: Urine specific gravity in 3 WUT markers (mean ± SD [effect size], 1.021 ± 0.007 [0.57]; P = 0.025) and 2 WUT markers (1.019 ± 0.010 [0.31]; P = 0.026) was significantly higher than 1 WUT marker (1.016 ± 0.009). Urine mosmolality in 2 WUT markers (705 ± 253 mOsmol [0.43]; P = 0.018) was significantly higher than 1 WUT (597 ± 253 mOsmol). Meeting at 3 WUT resulted in specificity of 0.956 and at 0 WUT resulted in sensitivity of 0.937 for urine osmolality>700mOsm. Conclusion: These results suggest that when 3 WUT markers are met, urine specific gravity and urine osmolality indicated hypohydration and 0 WUT represents a high likelihood of euhydration. 1 and 2 WUT values are indeterminate of hydration status. The WUT criterion is a useful tool to use in field settings to assess hydration status when first morning urine sample was used. Clinical Relevance: Athletes, coaches, sports scientists, and medical professionals can use WUT criteria to monitor dehydration with reduced cost and time. [ABSTRACT FROM AUTHOR]

Extreme heat can be harmful to human health and negatively affect athletic performance. The Tokyo Olympic and Paralympic Games are predicted to be the most oppressively hot Olympics on record. An interdisciplinary multi-scale perspective is provided concerning extreme heat in Tokyo—from planetary atmospheric dynamics, including El Niño Southern Oscillation (ENSO), to fine-scale urban temperatures—as relevant for heat preparedness efforts by sport, time of day, and venue. We utilize stochastic methods to link daytime average wet bulb globe temperature (WBGT) levels in Tokyo in August (from meteorological reanalysis data) with large-scale atmospheric dynamics and regional flows from 1981 to 2016. Further, we employ a mesonet of Tokyo weather stations (2009–2018) to interpolate the spatiotemporal variability in near-surface air temperatures at outdoor venues. Using principal component analysis, two planetary (ENSO) regions in the Pacific Ocean explain 70% of the variance in Tokyo's August daytime WBGT across 35 years, varying by 3.95°C WGBT from the coolest to warmest quartile. The 10-year average daytime and maximum intra-urban air temperatures vary minimally across Tokyo (<1.2°C and 1.7°C, respectively), and less between venues (0.6–0.7°C), with numerous events planned for the hottest daytime period (1200–1500 hr). For instance, 45% and 38% of the Olympic and Paralympic road cycling events (long duration and intense) occur midday. Climatologically, Tokyo will present oppressive weather conditions, and March–May 2020 is the critical observation period to predict potential anomalous late-summer WBGT in Tokyo. Proactive climate assessment of expected conditions can be leveraged for heat preparedness across the Game's period. [ABSTRACT FROM AUTHOR]

Context: Previous field research has not identified sweat rates (SR), fluid consumption (FC), or the efficacy of an educational intervention (EI) for youth during football camp. Objective: To measure hydration status and rehydration performance and examine EI using these data. Design: Observational with EI randomized comparison. Participants: Thirty-three boys (mean ± SD: 12 ± 2 y, 52.9 ± 13.6 kg, 156 ± 12 cm) volunteered during a 5-d camp with 3 (~2-h) sessions per day (WBGT: 25.6 ± 0.5°C). Main Outcome Measures: Hydration status, SR, and FC. Results: Urine osmolality averaged 796 ± 293 mOsm/L for days 2-5. Game SR (1.30 ± 0.57 L/h) was significantly greater than practice SR (0.65 ± 0.35 L/h; P = .002). Subjects dehydrated during free time but matched fluid losses with FC (0.76 ± 0.29 L/h) during football activities. Conclusions: Subjects arrived at camp hypohydrated and maintained this condition. They matched FC and SR during, but dehydrated when not playing, football. This may impair recovery and subsequent performance. Hydration EI seemed to have a positive influence on hydration practices. [ABSTRACT FROM AUTHOR]

This article focuses on exertional hyponatremia. It is a plasma sodium concentration less than 135 mmol/L (normal is 135-146 mmol/L). The condition most commonly occurs in low to moderate intensity events lasting 4 hour or more in a hot environment. Excessive fluid intake in athletes, hikers, and soldiers can be attributed to a recent heightened emphasis on water consumption for the prevention of heat illness and widespread ignorance of the potential for exertional hyponatremia. Increasing awareness of hydration as a preventive measure for heat illness, might have lead to the recent increase in the incidence of exertional hyponatremia.

The following organisations endorsed this document: American Association of Neurological Surgeons, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, American Osteopathic Academy of Sports Medicine, College Athletic Trainers' Society, Collegiate Strength and Conditioning Coaches Association, Congress of Neurological Surgeons, Korey Stringer Institute, National Athletic Trainers' Association, National Strength and Conditioning Association, National Operating Committee for Standards on Athletic Equipment, Sports Neuropsychology Society. The following organisation has affirmed the value of this document: American Academy of Neurology. The Second Safety in College Football Summit resulted in interassociation consensus recommendations for three paramount safety issues in collegiate athletics: (1) independent medical care for collegiate athletes; (2) diagnosis and management of sport-related concussion; and (3) year-round football practice contact for collegiate athletes. This document, the fourth arising from the 2016 event, addresses the prevention of catastrophic injury, including traumatic and non-traumatic death, in collegiate athletes. The final recommendations in this document are the result of presentations and discussions on key items that occurred at the summit. After those presentations and discussions, endorsing organisation representatives agreed on 18 foundational statements that became the basis for this consensus paper that has been subsequently reviewed by relevant stakeholders and endorsing organisations. This is the final endorsed document for preventing catastrophic injury and death in collegiate athletes. This document is divided into the following components. (1) Background-this section provides an overview of catastrophic injury and death in collegiate athletes. (2) Interassociation recommendations: preventing catastrophic injury and death in collegiate athletes-this section provides the final recommendations of the medical organisations for preventing catastrophic injuries in collegiate athletes. (3) Interassociation recommendations: checklist-this section provides a checklist for each member school. The checklist statements stem from foundational statements voted on by representatives of medical organisations during the summit, and they serve as the primary vehicle for each member school to implement the prevention recommendations. (4) References-this section provides the relevant references for this document. (5) Appendices-this section lists the foundational statements, agenda, summit attendees and medical organisations that endorsed this document. [ABSTRACT FROM AUTHOR]

Context: Exertional heat stroke (EHS) is a leading cause of sudden death in high school football players. Preparedness strategies can mitigate EHS incidence and severity. Objective: To examine EHS preparedness among high school football programs and its association with regional and state preseason heat-acclimatization mandates. Design: Cross-sectional study. Setting: Preseason high school football programs, 2017. Patients or Other Participants: A total of 910 athletic trainers (ATs) working with high school football (12.7% completion rate). Main Outcome Measure(s): We acquired data on high school football programs' EHS preparedness strategies in the 2017 preseason via an online questionnaire, looking at (1) whether schools' state high school athletic associations mandated preseason heat-acclimatization guidelines and (2) heat safety region based on warm-season wet-bulb globe temperature, ranging from the milder region 1 to the hotter region 3. Six EHS-preparedness strategies were assessed: EHS recognition and treatment education; policy for initiating emergency medical services response; emergency response plan enactment; immersion tub filled with ice water before practice; wet-bulb globe temperature monitoring; and hydration access. Multivariable binomial regression models estimated the prevalence of reporting all 6 strategies. Results: Overall, 27.5% of ATs described their schools as using all 6 EHS-preparedness strategies. The highest prevalence was in region 3 schools with state mandates (52.9%). The multivariable model demonstrated an interaction in which the combination of higher heat safety region and presence of a state mandate was associated with a higher prevalence of reporting all 6 strategies (P = .05). Controlling for AT and high school characteristics, the use of all 6 strategies was higher in region 3 schools with state mandates compared with region 1 schools without state mandates (52.9% versus 17.8%; prevalence ratio = 2.68; 95% confidence interval = 1.81, 3.95). Conclusions: Our findings suggest a greater use of EHSpreparedness strategies in environmentally warmer regions with state-level mandates for preseason heat acclimatization. Future researchers should identify factors influencing EHS preparedness, particularly in regions 1 and 2 and in states without mandates. [ABSTRACT FROM AUTHOR]

Context: Exertional heat illnesses (EHIs) among football athletes have been widely researched, but data examining all collegiate sports are limited. Objective: To describe the epidemiology of EHI in 25 National Collegiate Athletic Association (NCAA) sports. Design: Descriptive epidemiology study. Setting: The NCAA Injury Surveillance Program during the 2009-2010 through 2014-2015 academic years. Patients or Other Participants: A voluntary sample of 166 NCAA institutions over 2048 team-seasons. Main Outcome Measure(s): Athletic trainers reported EHIs to the NCAA Injury Surveillance Program. Only EHIs sustained during a sanctioned practice or competition were included. The EHI rate, specific diagnoses, and number of emergency transports were measured. Results: Overall, 232 EHI events were reported (0.47/10000 athlete-exposures [AEs]; 95% confidence interval [CI] = 0.41, 0.53). Football comprised 75% of all EHI events and had the largest rate (1.55/10000 AEs; 95% CI = 1.32, 1.78). The overall EHI rate was higher in preseason practices (1.16/10000 AEs) than all other time periods (regular and postseason practices and all competitions; 0.23/10000 AEs, injury rate ratio [IRR] = 4.96; 95% CI = 3.79, 6.50). This result was retained when examining the individual sports of football (3.65/10000 versus 0.63/10000 AEs, IRR = 5.82; 95% CI = 4.18, 8.10), men's soccer (1.11/10000 versus 0.07/10000 AEs, IRR = 16.819; 95% CI = 1.89, 138.55), and women's soccer (1.10/10000 versus 0.05/10000 AEs, IRR = 22.52; 95% CI = 2.77, 183.05). The EHI rates were highest in states with elevated annual temperatures (1.05/10000 AEs). Heat cramps (39%), heat exhaustion (27%), and dehydration (29%) were the most common types of EHI. Nineteen athletes with EHI (8%) required emergency transport. Conclusions: Football players continue to experience the most EHIs; however, EHIs can potentially occur in all NCAA sports. Continued emphasis on preseason EHI policies and institution-specific environmental guidelines is needed to address EHI rates. [ABSTRACT FROM AUTHOR]

Objectives: Cold water immersion (CWI) has been widely used for enhancing athlete recovery though its use following an Ironman triathlon has never been examined. The purpose of this paper is to determine the influence of CWI immediately following an Ironman triathlon on markers of muscle damage, inflammation and muscle soreness.Design: Prospective cohort study.Methods: Thirty three (22 male, 11 female), triathletes participating in the Ironman World Championships volunteered to participate (mean±SD: age=40±11years; height=174.5±9.1cm; body mass=70±11.8kg; percent body fat=11.4±4.1%, finish time=11:03.00±01:25.08). Post race, participants were randomly assigned to a 10-min bout of 10°C CWI or no-intervention control group. Data collection occurred pre-intervention (PRE), post-intervention (POST), 16h (16POST) and 40h (40POST) following the race. Linear mixed model ANOVA with Bonferroni corrections were performed to examine group by time differences for delayed onset muscle soreness (DOMS), hydration indices, myoglobin, creatine kinase (CK), cortisol, C-reactive protein (CRP), IL-6 and percent body mass loss (%BML). Pearson's bivariate correlations were used for comparisons with finishing time. Alpha level was set a priori at 0.05.Results: No significant group by time interactions occurred. Significant differences occurred for POST BML (-1.7±0.9kg) vs. 16POST, and 40POST BML (0.9±1.4, -0.1±1.2kg, respectively; p<0.001). Compared to PRE, myoglobin, CRP and CK remained significantly elevated at 40POST. Cortisol returned to PRE values by 16POST and IL-6 returned to PRE values by 40POST.Conclusion: A single bout of CWI did not provide any physiological benefit during recovery from a triathlon within 40h post race. Effect of CWI beyond this time is unknown. [ABSTRACT FROM AUTHOR]

Exertional heat stroke (EHS) is one of the most common causes of sudden death in athletes. It also represents a unique medical challenge to the prehospital healthcare provider due to the time sensitive nature of treatment. In cases of EHS, when cooling is delayed, there is a significant increase in organ damage, morbidity, and mortality after 30 minutes, faster than the average EMS transport and ED evaluation window. The purpose of this document is to present a paradigm for prehospital healthcare systems to minimize the risk of morbidity and mortality for EHS patients. With proper planning, EHS can be managed successfully by the prehospital healthcare provider. [ABSTRACT FROM AUTHOR]

Context: The presence of athletic trainers (ATs) in secondary schools to provide medical care is crucial, especially with the rise in sports participation and resulting high volume of injuries. Previous authors have investigated the level of AT services offered, but the differences in medical care offered between the public and private sectors have not been explored. Objective: To compare the level of AT services in public and private secondary schools. Design: Concurrent mixed-methods study. Setting: Public and private secondary schools in the United States. Patients or Other Participants: A total of 10 553 secondary schools responded to the survey (8509 public, 2044 private). Main Outcome Measure(s): School administrators responded to the survey via telephone or e-mail. Descriptive statistics depict national data. Open-ended questions were evaluated through content analysis. Results: A greater percentage of public secondary schools than private secondary schools hired ATs. Public secondary schools provided a higher percentage of full-time, part-time, and clinic AT services than private secondary schools. Only per diem AT services were more frequent in the private sector. Regardless of the extent of services, reasons for not employing an AT were similar between sectors. Common barriers were budget, school size, and lack of awareness of the role of an AT. Unique to the public sector, remote location was identified as a challenge faced by some administrators. Conclusions: Both public and private secondary schools lacked ATs, but higher percentages of total AT services and fulltime services were available in the public sector. Despite differences in AT services, both settings provided a similar number of student-athletes with access to medical care. Barriers to hiring ATs were comparable between public and private secondary schools; however, remote location was a unique challenge for the public sector. [ABSTRACT FROM AUTHOR]

Context: Availability of athletic trainer (AT) services in US secondary schools has recently been reported to be as high as 70%, but this only describes the public sector. The extent of AT coverage in private secondary school settings has yet to be investigated and may differ from the public secondary school setting for several reasons, including differences in funding sources. Objective: To determine the level of AT services in US private secondary schools and identify the reasons why some schools did not employ ATs. Design: Concurrent mixed-methods study. Setting: Private secondary schools in the United States. Patients or Other Participants: Of 5414 private secondary schools, 2044 (38%) responded to the survey. Main Outcome Measure(s): School administrators responded to the survey via telephone or e-mail. This instrument was previously used in a study examining AT services among public secondary schools. Descriptive statistics provided national data. Open-ended questions were evaluated through content analysis. Results: Of the 2044 schools that responded, 58% (1176/ 2044) offered AT services, including 28% (574/2040) full time, 25% (501/2042) part time, 4% (78/1918) per diem, and 20% (409/2042) from a hospital or clinic. A total of 84% (281 285/ 336165) of athletes had access to AT services. Larger private secondary schools were more likely to have AT services available. Barriers to providing AT services in the private sector were budgetary constraints, school size and sports, and lack of awareness of the role of an AT. Conclusions: More than half of the surveyed private secondary schools in the United States had AT services available; however, only 28% had a full-time AT. This demonstrates the need for increased medical coverage to provide athletes in this setting the appropriate level of care. Budgetary concerns, size of the school and sport offerings, and lack of awareness of the role of the AT continued to be barriers in the secondary school setting. [ABSTRACT FROM AUTHOR]

Context: Knowledge about the specific environmental and practice risks to participants in American intercollegiate football during preseason practices is limited. Identifying risks may mitigate occurrences of exertional heat illness (EHI). Objective: To evaluate the associations among preseason practice day, session number, and wet bulb globe temperature (WBGT) and the incidence of EHI. Design: Descriptive epidemiology study. Setting: Sixty colleges and universities representing 5 geographic regions of the United States. Patients or Other Participants: National Collegiate Athletic Association football players. Main Outcome Measure(s): Data related to preseason practice day, session number, and WBGT. We measured WBGT every 15 minutes during the practice sessions and used the mean WBGT from each session in the analysis. We recorded the incidence of EHIs and calculated the athlete-exposures (AEs). Results: A total of 553 EHI cases and 365 810 AEs were reported for an overall EHI rate of 1.52/1000 AEs (95% confidence interval [CI] = 1.42, 1.68). Approximately 74% (n = 407) of the reported EHI cases were exertional heat cramps (incidence rate = 1.14/1000 AEs; 95% CI = 1.03, 1.25), and about 26% (n = 146) were a combination of exertional heat syncope and heat exhaustion (incidence rate = 0.40/1000 AEs; 95% CI = 0.35, 0.48). The highest rate of EHI occurred during the first 14 days of the preseason period, and the greatest risk was during the first 7 days. The risk of EHI increased substantially when the WBGT was 82.0°F (27.8°C) or greater. Conclusions: We found an increased rate of EHI during the first 14 days of practice, especially during the first 7 days. When the WBGT was greater than 82.0°F (27.8°C), the rate of EHI increased. Sports medicine personnel should take all necessary preventive measures to reduce the EHI risk during the first 14 days of practice and when the environmental conditions are greater than 82.0°F (27.8°C) WBGT. [ABSTRACT FROM AUTHOR]

Exertional heat illness is a category of conditions commonly seen during sports participation in the hot summer months. Exertional heat stroke, in particular, is a dangerous condition involving hyperthermia and central nervous system dysfunction, which, if not properly treated, is potentially deadly. All on-site medical personnel, emergency physicians, and coaches involved in sports participation need to be aware of the recognition and treatment of heat illnesses. Emergency physicians must be equally aware of recognition, treatment, and return-to-play decisions to ensure athletes are quickly and effectively treated and return to sport participation safely. [ABSTRACT FROM AUTHOR]

The article discusses the issues related to exertional heat stroke (EHS) cause and care. It examines the predisposing factors, errors in care, and physiology of cold water immersion. It summarizes return-to-play (RTP) guidelines set by American College of Sports Medicine that provide a process for guiding athletes who are returning to training and competition after EHS.

The article reports on research conducted to evaluate the influence hydration status had on pacing during trail running in the heat. Researchers evaluated 17 well conditioned distance runners. They found that hydrated runners were able to pace themselves effectively and that dehydration is associated with decreases in runners' ability to evenly pace themselves during a competitive situation.

The article reports on the study that examines the combined effect of hydration state and resistance exercise on markers of muscle damage. The study found that hypohydration did not enhance muscle damage following the resistance exercise challenge. It suggests athletes to commence exercise in a euhydrated state to maximize endogenous hormonal, metabolic, and mechanical benefits.

The article reports that few caffeine studies have been published which include cognitive and physiologic considerations for the athlete. Lower doses of caffeine can be as effective as higher doses during exercise performance without any negative coincidence. Caffeine can improve the cognitive aspects of performance when an athlete has not slept well.

Recommends practices regarding fluid replacement for athletic participation from the National Athletic Trainers' Association (NATA). Physiologic implications of dehydration and exercise; Percentage of water in the human body; Purposes of rehydration; Assessment of hydration status; Signs and symptoms of dehydration.

The article discusses several points to consider when deciding whether or not to return to competitive athletics after suffering exertional heat stroke (EHS). While some people who experienced EHS may recover quickly, they are still at risk for heat stroke. This is due to the fact that many of the underlying causes, such as insufficient heat acclimatization, high body fat, or improper rehydration, are still present and, therefore, pose a hazard to individuals. The effects of EHF also can decrease the body's ability to thermoregulate, also increasing the risk for recurrence.

Repeated exercise heat exposures enhance exercise performance through a complex series of adaptations that are referred to as heat acclimatization (HAz), which occurs in an artificial environment, and heat acclimation (HA), which occurs in a natural environment. Special considerations are needed to induce adaptations and verify HAz and HA status. To ensure the effectiveness of each session, sufficient duration of exercise-induced hyperthermia is required. To this end, environmental conditions and exercise frequency, intensity, time, type, volume, and progression can be adjusted to achieve optimal adaptations. Furthermore, adaptations are typically lost within 1 week to 1 month following the cessation of exercise heat exposure and maintenance of adaptations is an important factor. Additionally, selecting the appropriate testing procedure is critical to ensure an athlete's HAz and HA status. The purpose of the current study was to provide various HAz and HA frameworks based on different sports so clinicians can implement HAz and HA to optimize performance. [Athletic Training & Sports Health Care. 2021;13(4):e238–e246.] [ABSTRACT FROM AUTHOR]

The article presents a study which investigates the effects of hypohydration on running and physiological responses. One study performed four experiments on euhydrated and hypohydration state with ten highly trained collegiate distance runners participants. The results show that there was no between-treatment differences on running economy, concentration on plasma lactate, and perceived exertion's rating. In addition, hypohydration indicates greater heart rate, rectal temperature, and concentration on plasma norepinephrine. The study concludes further that hypohydration did not change the running economy or lactate accumulation of endurance athletes which indicates that running economy was not affected by hypohydration.

There are no validated, objective diagnostic or prognostic biomarkers for sports-related concussion (SRC), which hinders evidence-based treatment for concussed athletes. While quantitative electrophysiology (EEG) and diffusion tensor imaging (DTI) are promising technologies for providing objective biomarkers for concussion, the degree to which they are related has not been systematically investigated in concussed athletes. This study examined whether diffusion metrics differentiated concussed athletes with prolonged recovery (n = 18) from non-conccused athletes (n = 13) and whether observed diffusion alterations related to EEG. Collegiate athletes (N = 31) completed EEG, neurocognitive, and magnetic resonance imaging. White matter diffusivity differed between the groups in multiple white matter tracts, including the corpus callosum, cingulum bundle, thalamic radiations, and inferior fronto-occipital, inferior longitudinal, and uncinate fasciculi, but not after correction for multiple comparisons. The enhanced Brain Function Index (eBFI), a measure that combines EEG and neurocognitive data, significantly correlated with altered diffusion in the concussed athletes. These preliminary findings suggest that the absolute deviation of diffusion metrics in concussed versus non-concussed athletes may have clinically utility. Results also suggested that the eBFI may be sensitive to early changes from sports-related concussion. [ABSTRACT FROM AUTHOR]