scholarly journals Exertional Heat Illness in American Football Players: When Is the Risk Greatest?

2016 ◽  
Vol 51 (8) ◽  
pp. 593-600 ◽  
Author(s):  
Earl R. Cooper ◽  
Michael S. Ferrara ◽  
Douglas J. Casa ◽  
John W. Powell ◽  
Steven P. Broglio ◽  
...  
Keyword(s):  
Incidence Rate ◽  
Sports Medicine ◽  
National Collegiate Athletic Association ◽  
The United States ◽  
American Football ◽  
Football Players ◽  
Heat Illness ◽  
Wet Bulb Globe Temperature ◽  
Exertional Heat Illness ◽  
Globe Temperature

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.

Exertional heat illness and acute injury related to ambient wet bulb globe temperature

2016 ◽  
Vol 59 (12) ◽  
pp. 1169-1176 ◽  
Author(s):  
Ximena P. Garzon-Villalba ◽  
Alfred Mbah ◽  
Yougui Wu ◽  
Michael Hiles ◽  
Hanna Moore ◽  
...  
Keyword(s):  
Acute Injury ◽  
Heat Illness ◽  
Wet Bulb Globe Temperature ◽  
Exertional Heat Illness ◽  
Globe Temperature

scholarly journals Sweat Rates, Sweat Sodium Concentrations, and Sodium Losses in 3 Groups of Professional Football Players

2010 ◽  
Vol 45 (4) ◽  
pp. 364-371 ◽  
Author(s):  
Sandra Fowkes Godek ◽  
Chris Peduzzi ◽  
Richard Burkholder ◽  
Steve Condon ◽  
Gary Dorshimer ◽  
...  
Keyword(s):  
Sweat Rate ◽  
Sodium Concentration ◽  
American Football ◽  
Football Players ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature ◽  
The Right ◽  
Practice Time ◽  
Sweat Sodium Concentration ◽  
Sweat Sodium

Abstract Context: Sweat sodium losses have never been reported in a large cohort of American football players. Objective: To compare sweat rates (SwtRs), sweat sodium concentrations (SwtNa+), and sodium losses in 3 groups of players (backs and receivers [BK], linebackers and quarterbacks [LB/QB], and linemen [LM]) to determine if positional differences and, therefore, size differences exist. Design: Observational study. Setting: Data were collected during practices in the second week of 2 consecutive training camps. The wet bulb globe temperature was 78.5°F ± 3.5°F (25.9°C ± 1.9°C). Patients or Other Participants: Eighteen BK, 12 LB/QB, and 14 LM volunteered. Intervention(s): Sterile sweat patches were applied to the right forearm after the skin was appropriately cleaned. The patches were removed during practice, placed in sterile tubes, centrifuged, frozen, and later analyzed by flame photometry. Main Outcome Measure(s): Sweat rate, SwtNa+, and sodium loss. We calculated SwtR by change in mass adjusted for urine produced and fluids consumed divided by practice time in hours. Results: Other than age, physical characteristics were different among groups (P < .001). The SwtR was different among groups (F2,41  =  7.3, P  =  .002). It was lower in BK (1.42 ± 0.45 L/h) than in LB/QB (1.98 ± 0.49 L/h) (P < .05) and LM (2.16 ± 0.75 L/h) (P < .01), but we found no differences between SwtRs for LB/QB and LM. The SwtNa+ was not different among groups (BK  =  50 ± 16 mEq/L, LB/QB  =  48.2 ± 23 mEq/L, and LM  =  52.8 ± 25 mEq/L) and ranged from 15 to 99 mEq/L. Sweat sodium losses ranged from 642 mg/h to 6.7 g/h, and findings for group comparisons approached significance (P  =  .06). On days when players practiced 4.5 hours, calculated sodium losses ranged from 2.3 to 30 g/d. Conclusions: The BK sweated at lower rates than did the midsized LB/QB and large LM, but LB/QB sweated similarly to LM. Sweat sodium concentration and daily sodium losses ranged considerably. Heavy, salty sweaters require increased dietary consumption of sodium during preseason.

scholarly journals Identifying the need for locally-observed wet bulb globe temperature across outdoor athletic venues for current and future climates in a desert environment

2021 ◽  
Author(s):  
Haven Guyer ◽  
Matei Georgescu ◽  
David M Hondula ◽  
Floris Wardenaar ◽  
Jennifer Vanos
Keyword(s):  
Climate Projections ◽  
Design Strategies ◽  
Local Cooling ◽  
Wet Bulb Globe Temperature ◽  
Exertional Heat Illness ◽  
Cooling Design ◽  
Weather Stations ◽  
Globe Temperature ◽  
Sports Venues ◽  
Projected Changes

Abstract Exertional heat illness and stroke are serious concerns across youth and college sports programs. While some teams and governing bodies have adopted the wet bulb globe temperature (WBGT), few practitioners use measurements on the field of play; rather, they often rely on regionally modeled or estimated WBGT. However, urban development-induced heat and projected climate change increase exposure to heat. We examined WBGT levels between various athletic surfaces and regional weather stations under current and projected climates and in hot-humid and hot-dry weather regimes in the southwest U.S. in Tempe, Arizona. On-site sun-exposed WBGT data across five days (07:00–19:00 local time) in June (dry) and August (humid) were collected over five athletic surfaces: rubber, artificial turf, clay, grass, and asphalt. Weather stations data were used to estimate regional WBGT (via the Liljegren model) and compared to on-site, observed WBGT. Finally, projected changes to WBGT were modeled under mid-century and late-century conditions. On-field WBGT observations were, on average, significantly higher than WBGT estimated from regional weather stations by 2.4°C–2.5°C, with mean on-field WBGT across both months of 28.52.76°C (versus 25.83.21°C regionally). However, between-athletic surface WBGT differences were largely insignificant. Significantly higher mean WBGTs occurred in August (30.12.35°C) versus June (26.92.19°C) across all venues; August conditions reached ‘limit activity’ or ‘cancellation’ thresholds for 6–8 hours and 2–4 hours of the day, respectively, for all sports venues. Climate projections show increased WBGTs across measurement locations, dependent on projection and period, with average August WBGT under the highest representative concentration pathway causing all-day activity cancellations. Practitioners are encouraged to use WBGT devices within the vicinity of the fields of play, yet should not rely on weather station estimations without corrections used. Heat concerns are expected to increase in the future, underlining the need for athlete monitoring, local cooling design strategies, and heat adaptation for safety.

scholarly journals Exertional heat illness risk factors and physiological responses of youth football players

2019 ◽  
Author(s):  
Susan W. Yeargin ◽  
John J. Dickinson ◽  
Dawn M. Emerson ◽  
Jessica Koller ◽  
Toni M. Torres-McGehee ◽  
...  
Keyword(s):  
Risk Factors ◽  
Physiological Responses ◽  
Football Players ◽  
Heat Illness ◽  
Exertional Heat Illness ◽  
Youth Football

scholarly journals Sweat Rates and Fluid Turnover in Professional Football Players: A Comparison of National Football League Linemen and Backs

2008 ◽  
Vol 43 (2) ◽  
pp. 184-189 ◽  
Author(s):  
Sandra Fowkes Godek ◽  
Arthur R. Bartolozzi ◽  
Richard Burkholder ◽  
Eric Sugarman ◽  
Chris Peduzzi
Keyword(s):  
Weight Loss ◽  
National Football League ◽  
Sweat Rate ◽  
Large Body ◽  
Football Players ◽  
Practice Session ◽  
Mass Measurements ◽  
Sweat Loss ◽  
Wet Bulb Globe Temperature ◽  
Globe Temperature

Abstract Context: Many National Football League (NFL) teams practice 2 times per day over consecutive days in a hot and humid environment. Large body surface area (BSA) and use of protective equipment result in high sweat rates and total sweat loss in these football players. Objective: To compare sweat rate, sweat loss, fluid consumption, and weight loss between NFL linemen and backs during preseason practices. Design: Between-groups design. Setting: Preseason training camp with wet bulb globe temperature between 19°C and 25°C. Patients or Other Participants: Eight linemen and 4 backs and receivers participated. Main Outcome Measure(s): Data were collected during both practice sessions on 2 separate days during the first week of August. Sweat rate was calculated as change in mass adjusted for all fluids consumed between prepractice and postpractice body mass measurements and the urine produced during practice divided by the length of the practice session. Gross daily sweat losses also were calculated. Results: Height, mass, and BSA were higher in linemen than in backs. Sweat rate was also higher in linemen (2385 ± 520 mL/h) than in backs (1410 ± 660 mL/h, P < .001), as was the total volume of sweat lost during both practices in 1 day (6870 ± 1034 mL/d versus 4110 ± 2287 mL/d, P  =  .014). Compared with backs, linemen consumed more fluids during practice (2030 ± 849 mL versus 1179 ± 753 mL, P  =  .025) but produced less urine (53 ± 73 mL versus 163 ± 141 mL, P  =  .018). There was no difference in postpractice weight loss (linemen  =  −1.15 ± 0.83%, backs  =  −1.06 ± 0.76%). Conclusions: Linemen sweated at higher rates, lost larger volumes of sweat, consumed more fluids, and produced less urine during practice compared with the physically smaller backs, but they did not lose a greater percentage of body weight. Sodium losses could be considerable in NFL players during the preseason because of high daily sweat losses in backs and in linemen.

Posturing Responses in Concussions Sustained by Elite American Football Players

2020 ◽  
Vol 25 (4) ◽  
pp. 203-207
Author(s):  
Scott L. Bruce ◽  
Kyra Dorney
Keyword(s):  
Current Literature ◽  
Brain Injuries ◽  
National Football League ◽  
National Collegiate Athletic Association ◽  
American Football ◽  
Football Players ◽  
Loss Of Consciousness ◽  
Inclusion Criteria ◽  
Association Football ◽  
Football Game

Current literature indicates loss of consciousness occurs in about 10% of concussions. Posturing presentations represent brain injuries and a loss of consciousness. The purpose of this study was to observe video evidence of football-game-related concussions to determine the rate in which a posturing presentation occurs in reported concussion. Over the course of three National Football League and three National Collegiate Athletic Association football seasons, 103 videos of 805 reported concussions met the inclusion criteria; 35 videos demonstrated a posturing presentation, for a rate of 33.98%. Our study indicates that the published statistic regarding loss of consciousness (occurring only about 10% of the time) may be too conservative.

Wet Bulb Globe Temperature Use in National Collegiate Athletic Association Football Bowl Subdivision Athletic Training Staffs

2020 ◽  
Vol 25 (6) ◽  
pp. 314-317
Author(s):  
Garrison A. Chan ◽  
Dale R. Wagner
Keyword(s):  
Athletic Training ◽  
National Collegiate Athletic Association ◽  
Athletic Trainers ◽  
Geographical Location ◽  
Football Bowl Subdivision ◽  
Wet Bulb Globe Temperature ◽  
Association Football ◽  
National Athletic Trainers Association ◽  
Globe Temperature ◽  
The University

Heat illnesses present a risk for athletes, especially football players. The National Athletic Trainers’ Association established recommendations to prevent heat illnesses, which include measuring wet bulb globe temperature (WBGT). This study aimed to determine the prevalence of WBGT use among the 130 National Collegiate Athletic Association Football Bowl Subdivision athletic training staffs. Of 82 respondents, 59 use WBGT to assess heat stress. The majority of Football Bowl Subdivision training programs (72% of respondents) use the WBGT, but adherence to this National Athletic Trainers’ Association recommendation varies throughout the season (practice versus games) and is likely influenced by the geographical location of the university.

scholarly journals Nontraumatic Exertional Fatalities in Football Players, Part 1: Epidemiology and Effectiveness of National Collegiate Athletic Association Bylaws

2020 ◽  
Vol 8 (8) ◽  
pp. 232596712094249 ◽  
Author(s):  
Barry P. Boden ◽  
Ken M. Fine ◽  
Ilan Breit ◽  
Wendee Lentz ◽  
Scott A. Anderson
Keyword(s):  
Ncaa Division I ◽  
National Collegiate Athletic Association ◽  
Sickle Cell Trait ◽  
Heat Stroke ◽  
The United States ◽  
National Registry ◽  
Division I ◽  
Football Players ◽  
Incidence Trends ◽  
The 1960S

Background: Football has the highest number of nontraumatic fatalities of any sport in the United States. Purpose: To compare the incidence of nontraumatic fatalities with that of traumatic fatalities, describe the epidemiology of nontraumatic fatalities in high school (HS) and college football players, and determine the effectiveness of National Collegiate Athletic Association (NCAA) policies to reduce exertional heat stroke (EHS) and exertional sickling (ES) with sickle cell trait (SCT) fatalities in athletes. Study Design: Descriptive epidemiology study. Methods: We retrospectively reviewed 20 academic years (1998-2018) of HS and college nontraumatic fatalities in football players using the National Registry of Catastrophic Sports Injuries (NRCSI). EHS and ES with SCT fatality rates were compared before and after the implementation of the NCAA football out-of-season model (bylaw 17.10.2.4 [2003]) and NCAA Division I SCT screening (bylaw 17.1.5.1 [2010]), respectively. Additionally, we compiled incidence trends for HS and college traumatic and nontraumatic fatalities in football players for the years 1960 through 2018 based on NRCSI data and previously published reports. Results: The risk (odds ratio) of traumatic fatalities in football players in the 2010s was 0.19 (95% CI, 0.13-0.26; P < .0001) lower in HS and 0.29 (95% CI, 0.29-0.72; P = .0078) lower in college compared with that in the 1960s. In contrast, the risk of nontraumatic fatalities in football players in the 2010s was 0.7 (95% CI, 0.50-0.98; P = .0353) in HS and 0.9 (95% CI, 0.46-1.72; P = .7413) in college compared with that in the 1960s. Since 2000, the risk of nontraumatic fatalities has been 1.89 (95% CI, 1.42-2.51; P < .001) and 4.22 (95% CI, 2.04-8.73; P < .001) higher than the risk of traumatic fatalities at the HS and college levels, respectively. During the 20 years studied, there were 187 nontraumatic fatalities (average, 9.4 per year). The causes of death were sudden cardiac arrest (57.7%), EHS (23.6%), ES with SCT (12.1%), asthma (4.9%), and hyponatremia (1.6%). The risk of a nontraumatic fatality was 4.1 (95% CI, 2.8-5.9; P < .0001) higher in NCAA compared with HS athletes. There was no difference in the risk of an EHS fatality in NCAA athletes (0.86 [95% CI, 0.17-4.25]; P = .85) after implementation in 2003 of the NCAA football out-of-season model. The risk of an ES with SCT fatality in Division I athletes was significantly lower after the 2010 NCAA SCT screening bylaw was implemented (0.12 [95% CI, 0.02-0.95]; P = .04). Conclusion: Since the 1960s, the risk of nontraumatic fatalities has declined minimally compared with the reduction in the risk of traumatic fatalities. Current HS and college nontraumatic fatality rates are significantly higher than rates of traumatic fatalities. The 2003 NCAA out-of-season model has failed to significantly reduce EHS fatalities. The 2010 NCAA SCT screening bylaw has effectively prevented ES with SCT fatalities in NCAA Division I football.

Collegiate Marching Band Artists Experience High Core Body Temperatures during Rehearsals and Performances

2020 ◽  
Vol 2020 (preprint) ◽  
pp. 0000-0000
Author(s):  
Dawn M. Emerson ◽  
Toni M. Torres-McGehee ◽  
Susan W. Yeargin ◽  
Melani R. Kelly ◽  
Nancy Uriegas ◽  
...  
Keyword(s):  
Risk Factors ◽  
Sweat Rate ◽  
Management Strategies ◽  
Ground Surface ◽  
Urine Specific Gravity ◽  
Marching Band ◽  
Wet Bulb Globe Temperature ◽  
Exertional Heat Illness ◽  
Globe Temperature ◽  
Hydration Characteristics

Abstract Context: No research has investigated thermoregulatory responses and exertional heat illness (EHI) risk factors in marching band (MB) artists performing physical activity in high environmental temperatures. Objective: Examine core temperature (Tc) and EHI risk factors in MB artists. Design: Descriptive epidemiology study. Setting: Three rehearsals and 2 football games for 2 NCAA Division I MBs. Participants: Nineteen volunteers completed the study (female = 13, males = 6; age = 20.5 ± 0.9 years; weight = 75.0 ± 19.1 kg; height = 165.1 ± 7.1 cm). Main Outcome Measures: We measured Tc pre-, post-, and every 15 minutes during activity and recorded wet-bulb globe temperature (WBGT) and relative humidity (RH) every 15 minutes. Other variables included activity time and intensity, ground surface, hydration characteristics (fluid volume, sweat rate, urine specific gravity, percent body mass loss [%BM]), and medical history (eg, previous EHI, medications). Statistical analysis included descriptives (mean ± standard deviation), comparative analyses determined differences within and between days, and linear regression identified variables that significantly explained Tc. Results: Mean rehearsal time = 102.8 ± 19.8 minutes and game time = 260.5 ± 47.7 minutes. Max game Tc (39.1 ± 1.1°C) was significantly higher than rehearsal (38.4 ± 0.7°C, P = .003). The highest max game Tc = 41.2°C. Participants consumed significantly more fluid than their sweat rates (P &lt; .003), which minimized %BM loss, particularly during rehearsals (−0.4 ± 0.6%). Mean game %BM loss = −0.9 ± 2.0%; however, 63.6% of the time, participants reported hypohydrated to game day. Max Tc was significantly predicted by max WBGT, max RH, ground surface, using mental health medications, and hours of sleep (adjusted R2 = 0.542, P &lt; .001). Conclusions: Marching band artists experience high Tc during activity and should have access to athletic trainers who can implement EHI prevention and management strategies.

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