Smoljanić Jovana, Morris Nathan B, Dervis Sheila, Jay Ollie
School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; and.
School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada; and Thermal Ergonomics Laboratory, Exercise and Sports Science, Faculty of Health Sciences, University of Sydney, New South Wales, Australia.
J Appl Physiol (1985). 2014 Dec 15;117(12):1451-9. doi: 10.1152/japplphysiol.00665.2014. Epub 2014 Oct 9.
We sought to determine the independent influence of running economy (RE) and aerobic fitness [maximum oxygen consumption (V̇O 2max)] on thermoregulatory responses during treadmill running by conducting two studies. In study 1, seven high (HI-FIT: 61 ± 5 ml O2 · kg(-1) · min(-1)) and seven low (LO-FIT: 45 ± 4 ml O2 · kg(-1) · min(-1)) V̇O 2max males matched for physical characteristics and RE (HI-FIT: 200 ± 21; LO-FIT: 200 ± 18 ml O2 · kg(-1) · km(-1)) ran for 60 min at 1) 60%V̇O 2max and 2) a fixed metabolic heat production (Hprod) of 640 W. In study 2, seven high (HI-ECO: 189 ± 15.3 ml O2 · kg(-1) · km(-1)) and seven low (LO-ECO: 222 ± 10 ml O2 · kg(-1) · km(-1)) RE males matched for physical characteristics and V̇O 2max (HI-ECO: 60 ± 3; LO-ECO: 61 ± 7 ml O2 · kg(-1) · min(-1)) ran for 60 min at a fixed 1) speed of 10.5 km/h and 2) Hprod of 640 W. Environmental conditions were 25.4 ± 0.8°C, 37 ± 12% RH. In study 1, at Hprod of 640 W, similar changes in esophageal temperature (ΔTes; HI-FIT: 0.63 ± 0.20; LO-FIT: 0.63 ± 0.22°C; P = 0.986) and whole body sweat losses (WBSL; HI-FIT: 498 ± 66; LO-FIT: 497 ± 149 g; P = 0.984) occurred despite different relative intensities (HI-FIT: 55 ± 6; LO-FIT: 39 ± 2% V̇O 2max; P < 0.001). At 60% V̇O 2max, ΔTes (P = 0.029) and WBSL (P = 0.003) were greater in HI-FIT (1.14 ± 0.32°C; 858 ± 130 g) compared with LO-FIT (0.73 ± 0.34°C; 609 ± 123 g), as was Hprod (HI-FIT: 12.6 ± 0.9; LO-FIT: 9.4 ± 1.0 W/kg; P < 0.001) and the evaporative heat balance requirement (Ereq; HI-FIT: 691 ± 74; LO-FIT: 523 ± 65 W; P < 0.001). Similar sweating onset ΔTes and thermosensitivities occurred between V̇O 2max groups. In study 2, at 10.5 km/h, ΔTes (1.16 ± 0.31 vs. 0.78 ± 0.28°C; P = 0.017) and WBSL (835 ± 73 vs. 667 ± 139 g; P = 0.015) were greater in LO-ECO, as was Hprod (13.5 ± 0.6 vs. 11.3 ± 0.8 W/kg; P < 0.001) and Ereq (741 ± 89 vs. 532 ± 130 W; P = 0.007). At Hprod of 640 W, ΔTes (P = 0.910) and WBSL (P = 0.710) were similar between HI-ECO (0.55 ± 0.31°C; 501 ± 88 g) and LO-ECO (0.57 ± 0.16°C; 483 ± 88 g), but running speed was different (HI-ECO: 8.2 ± 0.6; LO-ECO: 7.2 ± 0.4 km/h; P = 0.025). In conclusion, thermoregulatory responses during treadmill running are not altered by V̇O 2max, but by RE because of differences in Hprod and Ereq.
我们通过两项研究来确定跑步经济性（RE）和有氧适能[最大摄氧量（V̇O₂max）]对跑步机跑步过程中体温调节反应的独立影响。在研究1中，七名高（HI-FIT：61±5 ml O₂·kg⁻¹·min⁻¹）和七名低（LO-FIT：45±4 ml O₂·kg⁻¹·min⁻¹）V̇O₂max的男性，他们在身体特征和RE方面相匹配（HI-FIT：200±21；LO-FIT：200±18 ml O₂·kg⁻¹·km⁻¹），分别在以下两种条件下跑60分钟：1）60%V̇O₂max；2）固定代谢产热（Hprod）为640 W。在研究2中，七名高（HI-ECO：189±15.3 ml O₂·kg⁻¹·km⁻¹）和七名低（LO-ECO：222±10 ml O₂·kg⁻¹·km⁻¹）RE的男性，他们在身体特征和V̇O₂max方面相匹配（HI-ECO：60±3；LO-ECO：61±7 ml O₂·kg⁻¹·min⁻¹），分别在以下两种条件下跑60分钟：1）固定速度10.5 km/h；2）Hprod为640 W。环境条件为25.4±0.8°C，37±12%相对湿度。在研究1中，在Hprod为640 W时，尽管相对强度不同（HI-FIT：55±6；LO-FIT：39±2%V̇O₂max；P<0.001），食管温度的变化（ΔTes；HI-FIT：0.63±0.20；LO-FIT：0.63±0.22°C；P = 0.986）和全身汗液流失（WBSL；HI-FIT：498±66；LO-FIT：497±149 g；P = 0.984）相似。在60%V̇O₂max时，与LO-FIT（0.73±0.34°C；609±123 g）相比，HI-FIT的ΔTes（P = 0.029）和WBSL（P = 0.003）更大，Hprod（HI-FIT：12.6±0.9；LO-FIT：9.4±1.0 W/kg；P<0.001）和蒸发散热平衡需求（Ereq；HI-FIT：691±74；LO-FIT：523±65 W；P<0.001）也是如此。V̇O₂max组之间的出汗起始ΔTes和热敏感性相似。在研究2中，在10.5 km/h时，LO-ECO的ΔTes（1.16±0.31 vs. 0.78±0.28°C；P = 0.017）和WBSL（835±73 vs. 667±139 g；P = 0.015）更大，Hprod（13.5±0.6 vs. 11.3±0.8 W/kg；P<0.001）和Ereq（741±89 vs. 532±130 W；P = 0.007）也是如此。在Hprod为640 W时，HI-ECO（0.55±0.31°C；501±88 g）和LO-ECO（0.57±0.16°C；483±88 g）之间的ΔTes（P = 0.910）和WBSL（P = 0.710）相似，但跑步速度不同（HI-ECO：8.2±0.6；LO-ECO：7.2±0.4 km/h；P = 0.025）。总之，跑步机跑步过程中的体温调节反应不受V̇O₂max的影响，而是受RE的影响，这是由于Hprod和Ereq的差异。
