Impaired Heat Adaptation From Combined Heat Training and 'Live High, Train Low' Hypoxia
| Autor: | Stephen Crowcroft, Erin L McCleave, Philo U. Saunders, Katie M. Slattery, Rob Duffield, Aaron J. Coutts, Avish P. Sharma |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Adult
Male Thermotolerance medicine.medical_specialty Hot Temperature Acclimatization Physical Therapy Sports Therapy and Rehabilitation Sweating 030204 cardiovascular system & hematology Biology Running 03 medical and health sciences Young Adult 0302 clinical medicine Heart Rate Internal medicine medicine Humans Orthopedics and Sports Medicine Plasma Volume Hypoxia Heat Adaptation 030229 sport sciences Hypoxia (medical) Cardiology Exercise Test Female medicine.symptom |
| Zdroj: | International journal of sports physiology and performance. 14(5) |
| ISSN: | 1555-0273 |
| Popis: | Purpose: To determine whether combining training in heat with “Live High, Train Low” hypoxia (LHTL) further improves thermoregulatory and cardiovascular responses to a heat-tolerance test compared with independent heat training. Methods: A total of 25 trained runners (peak oxygen uptake = 64.1 [8.0] mL·min−1·kg−1) completed 3-wk training in 1 of 3 conditions: (1) heat training combined with “LHTL” hypoxia (H+H; FiO2 = 14.4% [3000 m], 13 h·d−1; train at Results: Submaximal heart rate (effect size [ES] = −0.60 [−0.89; −0.32]) and core temperature (ES = −0.55 [−0.99; −0.10]) were reduced in HOT until 1 wkP. Sweat rate (ES = 0.36 [0.12; 0.59]) and sweat sodium concentration (ES = −0.82 [−1.48; −0.16]) were, respectively, increased and decreased until 3 wkP in HOT. Submaximal heart rate (ES = −0.38 [−0.85; 0.08]) was likely reduced in H+H at 3 wkP, whereas CONT had unclear physiological changes. Perceived exertion and thermal sensation were reduced across all groups. Conclusions: Despite greater physiological stress from combined heat training and “LHTL” hypoxia, thermoregulatory adaptations are limited in comparison with independent heat training. The combined stimuli provide no additional physiological benefit during exercise in hot environments. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|