Willmott Ashley G B, Hayes Mark, James Carl A, Gibson Oliver R, Maxwell Neil S
Centre for Sport and Exercise Science, Anglia Ruskin University, Cambridge, UK.
Environmental Extremes Laboratory, University of Brighton, Eastbourne, UK.
Temperature (Austin). 2019 Sep 19;7(2):178-190. doi: 10.1080/23328940.2019.1664370.
Athletes exercising in heat stress experience increased perceived fatigue acutely, however it is unknown whether heat acclimation (HA) reduces the magnitude of this perceptual response and whether different HA protocols influence the response. This study investigated sensations of fatigue following; acute exercise-heat stress; short- (5-sessions) and medium-term (10-sessions) HA; and between once- (ODHA) and twice-daily HA (TDHA) protocols. Twenty male participants (peak oxygen uptake: 3.75 ± 0.47 L·min-1) completed 10 sessions (60-min cycling at ~2 W·kg-1, 45°C/20% relative humidity) of ODHA (n = 10) or non-consecutive TDHA (n = 10). Sensations of fatigue (General, Physical, Emotional, Mental, Vigor and Total Fatigue) were assessed using the multi-dimensional fatigue scale inventory-short form pre and post session 1, 5 and 10. Heat adaptation was induced following ODHA and TDHA, with reductions in resting rectal temperature and heart rate, and increased plasma volume and sweat rate (P < 0.05). General, Physical and Total Fatigue increased from pre-to-post for session 1 within both groups (P < 0.05). Increases in General, Physical and Total Fatigue were attenuated in session 5 and 10 vs. session 1 of ODHA (P < 0.05). This change only occurred at session 10 of TDHA (P < 0.05). Whilst comparative heat adaptations followed ODHA and TDHA, perceived fatigue is prolonged within TDHA.
∆: Change; ANOVA: Analysis of variance; HA: Heat acclimation; HR: Heart rate; IL-6: Interleukin-6; MFS-SF: Multi-dimensional fatigue symptom inventory-short form (MFSI-SF); MTHA: Medium-term heat acclimation; Na: Sodium; ODHA: Once daily heat acclimation; PV: Plasma volume; RH: Relative humidity; RPE: Rating of perceived exertion; SD: Standard deviation; SE: Standard error of the slope coefficient or intercept; : Standard error of the estimate for the regression equation; STHA: Short-term heat acclimation; TDHA: Twice daily heat acclimation; TC: Thermal Comfort; T: Rectal temperature; TSS: Thermal sensation; V̇O: Peak oxygen uptake; WBSL: whole-body sweat loss.
在热应激环境中锻炼的运动员会在短时间内明显感到疲劳加剧，但目前尚不清楚热适应（HA）是否能减轻这种感知反应的程度，以及不同的热适应方案是否会对该反应产生影响。本研究调查了以下情况下的疲劳感：急性运动-热应激；短期（5次训练）和中期（10次训练）热适应；以及单日热适应（ODHA）和每日两次热适应（TDHA）方案之间的差异。20名男性参与者（峰值摄氧量：3.75±0.47L·min-1）完成了10次训练（在约2W·kg-1、45°C/20%相对湿度下进行60分钟骑行），其中10人采用ODHA方案，另外10人采用非连续的TDHA方案。在第1、5和10次训练前后，使用多维疲劳量表简表评估疲劳感（一般、身体、情绪、精神、活力和总疲劳）。ODHA和TDHA训练后均诱导了热适应，静息直肠温度和心率降低，血浆容量和出汗率增加（P<0.05）。两组中第1次训练前后的一般、身体和总疲劳感均增加（P<0.05）。与ODHA方案的第1次训练相比，第5次和第10次训练时一般、身体和总疲劳感的增加有所减弱（P<0.05）。这种变化仅在TDHA方案的第10次训练时出现（P<0.05）。虽然ODHA和TDHA方案都产生了相当的热适应效果，但TDHA方案下的疲劳感持续时间更长。
∆：变化；ANOVA：方差分析；HA：热适应；HR：心率；IL-6：白细胞介素-6；MFS-SF：多维疲劳症状量表简表（MFSI-SF）；MTHA：中期热适应；Na：钠；ODHA：单日热适应；PV：血浆容量；RH：相对湿度；RPE：自觉用力程度；SD：标准差；SE：斜率系数或截距的标准误差； ：回归方程估计值的标准误差；STHA：短期热适应；TDHA：每日两次热适应；TC：热舒适度；T：直肠温度；TSS：热感觉；V̇O：峰值摄氧量；WBSL：全身出汗量
