Launstein Ethan D, Miller Kevin C, O'Connor Paul, Adams William M, Abrego Megan L
College of Health Professions, Central Michigan University, Mount Pleasant, MI, USA.
Department of Kinesiology, University of North Carolina at Greensboro, Greensboro, NC, USA.
Temperature (Austin). 2021 Jan 4;8(3):245-253. doi: 10.1080/23328940.2020.1855958. eCollection 2021.
The Israeli Defense Force's heat tolerance test (HTT) helps clinicians make return-to-activity decisions following exertional heatstroke. Participants fail the test and are "heat intolerant" if rectal temperature (T) or heart rate (HR) exceed 38.5°C or 150 bpm, respectively. Ideally, tests assessing athlete heat tolerance would incorporate sport-specific factors (e.g., protective equipment). Because few clothes are worn during a HTT, its ability to assess American football players' heat tolerance may be limited. We hypothesized wearing an American football uniform (PADS) during a HTT would lead to more classifications of heat intolerance. In this randomized, counterbalanced, crossover study, 10 men without recent exertional heat illness (age: 23 ± 3 y; mass: 78.5 ± 10.3 kg; height: 179.6 ± 7.6 cm) completed a standard HTT (CONTROL) or an HTT with PADS donned. T and HR were monitored continuously for 2 hours or until T reached 39.5°C. We noted when HTT failure criteria occurred. All participants failed the HTT in PADS (n = 2, T >38.5°C; n = 8, HR >150 bpm); 5 failed in CONTROL (n = 1, T >38.5°C; n = 4, HR >150 bpm). Participants completed more of the HTT before failure in CONTROL than PADS (61.7 ± 23.5 min vs. 43.4 ± 14.2 min; t = 1.9, =.04). The HTT cannot be made more sport-specific by simply donning PADS because PADS impaired thermoregulatory ability and produced more false positive HTT results. Consequently, the HTT should not be the sole determinant of an American football players return-to-activity following heat illness. New methods of testing heat tolerance in American football players are needed since the existing HTT is not sport specific.ABBREVIATIONS: EHS: exertional heatstroke; HR: heart rate; HTT: The Israeli Defense Force's heat tolerance test; PADS: full American football uniform consisting of a helmet; shoulder, knee, thigh, hip and tailbone pads; a jersey top; undergarments; and half-length pants; PHT: probability of heat tolerance; RMANOVA: repeated measures analysis of variance; RPE: rating of perceived exertion; RTP: return to play; TCR: thermal-circulatory ratio; T rectal temperature; VO: maximal oxygen consumption.
以色列国防军的耐热性测试（HTT）有助于临床医生在劳力性热射病后做出恢复活动的决策。如果直肠温度（T）或心率（HR）分别超过38.5°C或150次/分钟，参与者测试不合格，即“耐热性差”。理想情况下，评估运动员耐热性的测试应纳入特定运动因素（如防护装备）。由于在HTT期间穿着的衣物很少，其评估美式橄榄球运动员耐热性的能力可能有限。我们假设在HTT期间穿着美式橄榄球制服（护具）会导致更多耐热性差的分类。在这项随机、平衡、交叉研究中，10名近期无劳力性热病史的男性（年龄：23±3岁；体重：78.5±10.3千克；身高：179.6±7.6厘米）完成了标准HTT（对照组）或穿着护具的HTT。连续监测T和HR 2小时或直至T达到39.5°C。我们记录了HTT失败标准出现的时间。所有参与者在穿着护具的HTT中均测试不合格（n = 2，T>38.5°C；n = 8，HR>150次/分钟）；5名在对照组中测试不合格（n = 1，T>38.5°C；n = 4，HR>150次/分钟）。与穿着护具相比，参与者在对照组中测试失败前完成HTT的时间更长（61.7±23.5分钟对43.4±14.2分钟；t = 1.9，P = 0.04）。仅仅穿上护具并不能使HTT更具运动特异性，因为护具会损害体温调节能力并产生更多HTT假阳性结果。因此，HTT不应成为美式橄榄球运动员热病史后恢复活动的唯一决定因素。由于现有的HTT并非特定于运动项目，因此需要新的方法来测试美式橄榄球运动员的耐热性。
EHS：劳力性热射病；HR：心率；HTT：以色列国防军的耐热性测试；PADS：由头盔、肩部、膝盖、大腿、臀部和尾骨护垫、运动衫上衣、内衣和短裤组成的完整美式橄榄球制服；PHT：耐热性概率；RMANOVA：重复测量方差分析；RPE：主观用力程度分级；RTP：恢复比赛；TCR：热循环比；T：直肠温度；VO：最大耗氧量
