Shortening Work-Rest Durations Reduces Physiological and Perceptual Load during Uphill Walking in Simulated Cold High-Altitude Conditions
| Parent link: | High Altitude Medicine and Biology Vol. 21, iss. 3.— 2020.— [P. 249-257] |
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| Other Authors: | , , , , , , , , , |
| Summary: | Title screen Shortening work-rest durations re-duces physiological and perceptual load during uphill walking in simulated cold high-altitude conditions.HighAlt Med Biol. 21:249–257, 2020.Background:We investigated the effects of two different work-rest durations on the physiological and per-ceptual responses to a simulated mountain hike in a cold hypoxic environment.Materials and Methods:Twelve healthy nonacclimatized active men (age 31.3–5.3 years, body mass index22.4–1.5 kg/m2) completed a 80-minute work-matched intermittent exercise on a motorized treadmill (25%incline, fixed self-selected speed), in a simulated mountain environment (-25°C, FiO2=11%,&5000 m a.s.l.),wearing extreme cold weather gear, once with short (20·3 minutes walking with 1 minute rest; SHORT) andonce with long (10·6 minutes walking with 2 minutes rest; LONG) work-rest durations. Heart rate (HR), pulseoxygen saturation (SpO2), rate of perceived exertion (RPE), and thermal sensation (TS) were assessed throughoutthe exercise protocols. Cardiac autonomic modulation was assessed before (PRE) and after exercise (POST) insupine position, as well as during standing resting periods by means of HR recovery (HRR) assessment.Results:SpO2and TS were similar (p>0.05) in SHORT and LONG protocols. HR and RPE were increased,and HRR reduced during LONG compared to SHORT (p<0.05). Parasympathetic activity indices were re-duced at POST after both protocols (p<0.05), but to a lesser extent after SHORT (p<0.05).Conclusions:Reduced work-rest durations are associated with improved perceptual responses and less per-turbation of cardiac autonomic balance, compared to longer work-rest durations. Shorter exercise periods frommore frequent breaks during hikes at high altitude may represent a valid strategy to limit the impact of exerciseunder extreme environmental conditions. |
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2020
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| Online Access: | https://doi.org/10.1089/ham.2019.0136 |
| Format: | Electronic Book Chapter |
| KOHA link: | https://koha.lib.tpu.ru/cgi-bin/koha/opac-detail.pl?biblionumber=666439 |