Preventing Exertional Heat Stroke in Football: Time for a Paradigm Shift.

CONTEXT: Among American sports, football has the highest incidence of exertional heat stroke (EHS), despite decades of prevention strategies. Based on recent reports, 100% of high school and college EHS football fatalities occur during conditioning sessions. Linemen are the at-risk population, constituting 97% of football EHS deaths. Linemen heat up faster and cool down slower than other players. EVIDENCE ACQUISITION: Case series were identified from organized, supervised football at the youth, high school, and collegiate levels and compiled in the National Registry of Catastrophic Sports Injuries. Sources for event occurrence were media reports and newspaper clippings, autopsy reports, certificates of death, school-sponsored investigations, and published medical literature. Articles were identified through PubMed with search terms "football," "exertional heat stroke," and "prevention." STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 5. RESULTS: Football EHS is tied to (1) high-intensity drills and conditioning that is not specific to individual player positions, (2) physical exertion as punishment; (3) failure to modify physical activity for high heat and humidity, (4) failure to recognize early signs and symptoms of EHS, and (5) death when cooling is delayed. CONCLUSION: To prevent football EHS, (1) all training and conditioning should be position specific; (2) physical activity should be modified per the heat load; (3) understand that some players have a "do-or-die" mentality that supersedes their personal safety; (4) never use physical exertion as punishment; (5) eliminate conditioning tests, serial sprints, and any reckless drills that are inappropriate for linemen; and (6) consider air-conditioned venues for linemen during hot practices. To prevent EHS, train linemen based on game demands. STRENGTH-OF-RECOMMENDATION TAXONOMY: n/a.

In-Season Nutrition Strategies and Recovery Modalities to Enhance Recovery for Basketball Players: A Narrative Review.

Basketball players face multiple challenges to in-season recovery. The purpose of this article is to review the literature on recovery modalities and nutritional strategies for basketball players and practical applications that can be incorporated throughout the season at various levels of competition. Sleep, protein, carbohydrate, and fluids should be the foundational components emphasized throughout the season for home and away games to promote recovery. Travel, whether by air or bus, poses nutritional and sleep challenges, therefore teams should be strategic about packing snacks and fluid options while on the road. Practitioners should also plan for meals at hotels and during air travel for their players. Basketball players should aim for a minimum of 8 h of sleep per night and be encouraged to get extra sleep during congested schedules since back-to back games, high workloads, and travel may negatively influence night-time sleep. Regular sleep monitoring, education, and feedback may aid in optimizing sleep in basketball players. In addition, incorporating consistent training times may be beneficial to reduce bed and wake time variability. Hydrotherapy, compression garments, and massage may also provide an effective recovery modality to incorporate post-competition. Future research, however, is warranted to understand the influence these modalities have on enhancing recovery in basketball players. Overall, a strategic well-rounded approach, encompassing both nutrition and recovery modality strategies, should be carefully considered and implemented with teams to support basketball players' recovery for training and competition throughout the season.

Selected In-Season Nutritional Strategies to Enhance Recovery for Team Sport Athletes: A Practical Overview.

Team sport athletes face a variety of nutritional challenges related to recovery during the competitive season. The purpose of this article is to review nutrition strategies related to muscle regeneration, glycogen restoration, fatigue, physical and immune health, and preparation for subsequent training bouts and competitions. Given the limited opportunities to recover between training bouts and games throughout the competitive season, athletes must be deliberate in their recovery strategy. Foundational components of recovery related to protein, carbohydrates, and fluid have been extensively reviewed and accepted. Micronutrients and supplements that may be efficacious for promoting recovery include vitamin D, omega-3 polyunsaturated fatty acids, creatine, collagen/vitamin C, and antioxidants. Curcumin and bromelain may also provide a recovery benefit during the competitive season but future research is warranted prior to incorporating supplemental dosages into the athlete's diet. Air travel poses nutritional challenges related to nutrient timing and quality. Incorporating strategies to consume efficacious micronutrients and ingredients is necessary to support athlete recovery in season.

Influence of Clothing on Thermoregulation and Comfort During Exercise in the Heat.

Davis, JK, Laurent, CM, Allen, KE, Zhang, Y, Stolworthy, NI, Welch, TR, and Nevett, ME. Influence of clothing on thermoregulation and comfort during exercise in the heat. J Strength Cond Res 31(12): 3435-3443, 2017-Sport textiles of synthetic fiber have been proposed to have superior properties for keeping wearers cooler, drier, and more comfortable compared with natural fibers. The impact of various fiber content and fabric construction on thermoregulation and perceptual responses are not well understood. Eight male collegiate athletes performed 3 counterbalanced trials of 45-minute treadmill run at 60% of maximal oxygen uptake in an environmental chamber (32° C). Three different fibers, consisting of 100% cotton, a blend of natural fibers (50/50% cotton/soybean), and a synthetic fiber (100% polyester) with mesh loops to facilitate ventilation through the clothing, were tested. Heat strain indices, microenvironment temperature, ratings of perceived exertion (RPE), and clothing comfort were measured. Session RPE (S-RPE) and session thermal sensation (S-TS) were recorded 20 minutes after each trial. There was no effect of clothing on rectal, skin, and body temperatures, heart rate, RPE, or comfort measures (p ≥ 0.05). A significant effect was observed for synthetic fiber compared with cotton on S-RPE (p = 0.03), S-TS (p = 0.04), and the microenvironment temperature at the chest (p = 0.02). No significant difference was shown for any other fibers on S-RPE, S-TS, or other microenvironment areas (p ≥ 0.05). These results show that clothing fiber content and fabric construction had no effect on thermoregulation, RPE, or clothing comfort during moderate-intensity exercise in the heat; whereas synthetic fabric construction indeed effectively reduced regional microenvironment temperature and attenuated global exertion and TS, which may have important implications for exercise tolerance in the heat.

Thermoregulation, Fluid Balance, and Sweat Losses in American Football Players.

Numerous studies have reported on the thermoregulation and hydration challenges athletes face in team and individual sports during exercise in the heat. Comparatively less research, however, has been conducted on the American Football player. Therefore, the purpose of this article is to review data collected in laboratory and field studies and discuss the thermoregulation, fluid balance, and sweat losses of American Football players. American Football presents a unique challenge to thermoregulation compared with other sports because of the encapsulating nature of the required protective equipment, large body size of players, and preseason practice occurring during the hottest time of year. Epidemiological studies report disproportionately higher rates of exertional heat illness and heat stroke in American Football compared with other sports. Specifically, larger players (e.g., linemen) are at increased risk for heat ailments compared with smaller players (e.g., backs) because of greater body mass index, increased body fat, lower surface area to body mass ratio, lower aerobic capacity, and the stationary nature of the position, which can reduce heat dissipation. A consistent finding across studies is that larger players exhibit higher sweating rates than smaller players. Mean sweating rates from 1.0 to 2.9 L/h have been reported for college and professional American Football players, with several studies reporting 3.0 L/h or more in some larger players. Sweat sodium concentration of American Football players does not seem to differ from that of athletes in other sports; however, given the high volume of sweat loss, the potential for sodium loss is higher in American Football than in other sports. Despite high sweating rates with American Football players, the observed disturbances in fluid balance have generally been mild (mean body mass loss ≤2 %). The majority of field-based studies have been conducted in the northeastern part of the United States, with limited studies in different geographical regions (i.e., southeast) of the United States. Further, there have been a limited number of studies examining body core temperature of American Football players during preseason practice, especially at the high school level. Future field-based research in American Football with various levels of competition in hotter geographical regions of the United States is warranted.

Crossmodal session rating of perceived exertion response at low and moderate intensities.

Session rating of perceived exertion (SRPE) permits global effort estimations after an exercise bout and has shown promise for evaluating training load. However, factors mediating SRPE are not well understood. The purpose of this study was to compare SRPE between cycling and treadmill exercise at low and moderate intensities. In a counterbalanced order, male subjects (n = 7) completed a VO2max trial on a cycle ergometer and a motor-driven treadmill. Then, participants completed trials at 50 and 75% mode-specific VO2max on a cycle ergometer (BK75, BK50) and a treadmill (TM75, TM50) to achieve ∼ 400-kcal energy expenditure per trial. Acute RPE (i.e., during exercise) at 5 minutes, midway, and test termination were recorded with SRPE (20-minutes postexercise) expressed as overall (SRPEO), legs (SRPEL), and breathing also recorded were heart rate (HR) and change in rectal temperature (ΔTrec). Significance was accepted at p ≤ 0.05. Repeated-measures analysis of variance revealed significantly greater SRPE for higher intensities within each mode. Crossmodal comparisons also show a higher SRPE at moderate (75% VO2max) intensities [SRPEO] = BK75: 7.6 ± 1.0, TM75: 6.9 ± 1.3) vs. lower (50% VO2max) intensities (BK50: 4.6 ± 1.4, TM50: 4.6 ± 1.1). Within modes, SRPE corresponded well with ΔTrec and HR. Acute RPE was linked with intensity and drifted upward across time. Results indicated that overall and differentiated SRPEs are magnified with exercise intensity with the corresponding disruption in internal environment potentially mediating subjective responses. From a practical application standpoint, SRPE provides a subjective assessment for immediate evaluation of daily training. Results indicate that, when using SRPE to monitor training, consideration should be given to responses across differing exercise modes.