Keen Megan L, Miller Kevin C, Zuhl Micah N
1School of Rehabilitation and Medical Sciences, Central Michigan University, Mount Pleasant, Michigan; and 2School of Health Sciences, Central Michigan University, Mount Pleasant, Michigan.
J Strength Cond Res. 2017 Nov;31(11):2983-2991. doi: 10.1519/JSC.0000000000002207.
Keen, ML, Miller, KC, and Zuhl, MN. Thermoregulatory and perceptual effects of a percooling garment worn underneath an American football uniform. J Strength Cond Res 31(11): 2983-2991, 2017-American football athletes are at the highest risk of developing exertional heat illness (EHI). We investigated whether percooling (i.e., cooling during exercise) garments affected perceptual or physiological variables in individuals exercising in the heat while wearing football uniforms. Twelve male participants (age = 24 ± 4 year, mass = 80.1 ± 8.5 kg, height = 182.5 ± 10.4 cm) completed this cross-over, counterbalanced study. On day 1, we measured peak oxygen consumption (V[Combining Dot Above]O2). On days 2 and 3, participants wore percooling garments with (ICE) or without (CON) ice packs over the femoral and brachial arteries. They donned a football uniform and completed 3, 20-minute bouts of treadmill exercise at ∼50% of peak V[Combining Dot Above]O2 (∼33° C, ∼42% relative humidity) followed by a 10-minute rest period. Ice packs were replaced every 20 minutes. Rating of perceived exertion (RPE), thermal sensation, and thirst sensation were measured before and after each exercise bout. Environmental symptoms questionnaire (ESQ) responses and urine specific gravity (Usg) were measured pretesting and after the last exercise bout. V[Combining Dot Above]O2, change in heart rate (ΔHR), and change in rectal temperature (ΔTrec) were measured every 5 minutes. Sweat rate, sweat volume, and percent hypohydration were calculated. No interactions (F17,187 ≤ 1.6, p ≥ 0.1) or main effect of cooling condition (F1,11 ≤ 1.4, p ≥ 0.26) occurred for ΔTrec, ΔHR, thermal sensation, thirst, RPE, ESQ, or Usg. No differences between conditions occurred for sweat volume, sweat rate, or percent hypohydration (t11 ≤ 0.7, p ≥ 0.25). V[Combining Dot Above]O2 differed between conditions over time (F15,165 = 3.3, p < 0.001); ICE was lower than CON at 30, 55, and 70 minutes (p ≤ 0.05). It is unlikely that these garments would prevent EHI or minimize dehydration in football athletes.
基恩，ML；米勒，KC；祖尔，MN。在美式橄榄球制服下穿着的预冷服装的体温调节和感知效果。《力量与体能研究杂志》31(11): 2983 - 2991，2017年 - 美式橄榄球运动员患运动性热疾病（EHI）的风险最高。我们调查了预冷（即在运动期间降温）服装是否会影响穿着橄榄球制服在高温环境下运动的个体的感知或生理变量。12名男性参与者（年龄 = 24 ± 4岁，体重 = 80.1 ± 8.5千克，身高 = 182.5 ± 10.4厘米）完成了这项交叉、平衡的研究。在第1天，我们测量了峰值耗氧量（V̇O₂）。在第2天和第3天，参与者在股动脉和肱动脉上方穿着带有（ICE）或不带有（CON）冰袋的预冷服装。他们穿上橄榄球制服，以约峰值V̇O₂的50%（约33℃，约42%相对湿度）完成3次、每次20分钟的跑步机运动，随后休息10分钟。每20分钟更换一次冰袋。在每次运动回合前后测量主观用力感觉（RPE）、热感觉和口渴感觉。在测试前和最后一次运动回合后测量环境症状问卷（ESQ）的回答和尿比重（Usg）。每5分钟测量一次V̇O₂、心率变化（ΔHR）和直肠温度变化（ΔTrec）。计算出汗率、出汗量和脱水百分比。对于ΔTrec、ΔHR、热感觉、口渴、RPE、ESQ或Usg，未出现交互作用（F17,187 ≤ 1.6，p ≥ 0.1）或冷却条件的主效应（F1,11 ≤ 1.4，p ≥ 0.26）。在出汗量、出汗率或脱水百分比方面，不同条件之间没有差异（t11 ≤ 0.7，p ≥ 0.25）。V̇O₂在不同条件下随时间有所不同（F15,165 = 3.3，p < 0.001）；在30、55和70分钟时，ICE组低于CON组（p ≤ 0.05）。这些服装不太可能预防橄榄球运动员的EHI或使脱水最小化。
