Dustin R Slivka1, Matthew W S Heesch2, Charles L Dumke3, John S Cuddy4, Walter S Hailes4, Brent C Ruby4. 1. School of Health, Physical Education and Recreation, University of Nebraska at Omaha, Omaha, NE (Dr Slivka and Mr Heesch). Electronic address: dslivka@unomaha.edu. 2. School of Health, Physical Education and Recreation, University of Nebraska at Omaha, Omaha, NE (Dr Slivka and Mr Heesch). 3. Department of Health and Human Performance, University of Montana, Missoula, MT (Dr Dumke). 4. Montana Center for Work Physiology and Exercise Metabolism, University of Montana, Missoula, MT (Mr Cuddy, Mr Hailes, and Dr Ruby).
Abstract
BACKGROUND: The ability to physically perform at high altitude may require unique strategies to acclimatize before exposure. The effect of acute hypoxic exposure on the metabolic response of the skeletal muscle may provide insight into the value of short-term preacclimatization strategies. OBJECTIVE: To determine the human skeletal muscle response to a single acute bout of exercise in a hypoxic environment on metabolic gene expression. METHODS:Eleven recreationally active male participants (24 ± 4 years, 173 ± 20 cm, 82 ± 12 kg, 15.2 ± 7.1% fat, 4.0 ± 0.6 L/min maximal oxygen consumption) completed two 1-hourcycling exercise trials at 60% of peak power followed by 4 hours of recovery in ambient environmental conditions (975 m) and at normobaric hypoxic conditions simulating 3000 m in a randomized counterbalanced order. Muscle biopsies were obtained from the vastus lateralis before exercise and 4 hours after exercise for real-time polymerase chain reaction analysis of select metabolic genes. RESULTS: Gene expression of hypoxia-inducible factor 1 alpha, cytochrome c oxidase subunit 4, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, hexokinase, phosphofructokinase, mitochondrial fission 1, and mitofusin-2 increased with exercise (P < .05) but did not differ with hypoxic exposure (P > .05). Optic atrophy 1 did not increase with exercise or differ between environmental conditions (P > .05). CONCLUSIONS: The improvements in mitochondrial function reported with intermittent hypoxic training may not be explained by a single acute hypoxic exposure, and thus it appears that a longer period of preacclimatization than a single exposure may be required.
RCT Entities:
BACKGROUND: The ability to physically perform at high altitude may require unique strategies to acclimatize before exposure. The effect of acute hypoxic exposure on the metabolic response of the skeletal muscle may provide insight into the value of short-term preacclimatization strategies. OBJECTIVE: To determine the human skeletal muscle response to a single acute bout of exercise in a hypoxic environment on metabolic gene expression. METHODS: Eleven recreationally active male participants (24 ± 4 years, 173 ± 20 cm, 82 ± 12 kg, 15.2 ± 7.1% fat, 4.0 ± 0.6 L/min maximal oxygen consumption) completed two 1-hour cycling exercise trials at 60% of peak power followed by 4 hours of recovery in ambient environmental conditions (975 m) and at normobaric hypoxic conditions simulating 3000 m in a randomized counterbalanced order. Muscle biopsies were obtained from the vastus lateralis before exercise and 4 hours after exercise for real-time polymerase chain reaction analysis of select metabolic genes. RESULTS: Gene expression of hypoxia-inducible factor 1 alpha, cytochrome c oxidase subunit 4, peroxisome proliferator-activated receptor gamma coactivator 1 alpha, hexokinase, phosphofructokinase, mitochondrial fission 1, and mitofusin-2 increased with exercise (P < .05) but did not differ with hypoxic exposure (P > .05). Optic atrophy 1 did not increase with exercise or differ between environmental conditions (P > .05). CONCLUSIONS: The improvements in mitochondrial function reported with intermittent hypoxic training may not be explained by a single acute hypoxic exposure, and thus it appears that a longer period of preacclimatization than a single exposure may be required.
Authors: Erich Hohenauer; Livia Freitag; Miriam Herten; Julia Siallagan; Elke Pollock; Wolfgang Taube; Ron Clijsen Journal: Front Physiol Date: 2022-06-16 Impact factor: 4.755
Authors: Elliott C R Hall; Christopher Murgatroyd; Georgina K Stebbings; Brian Cunniffe; Lee Harle; Matthew Salter; Aroul Ramadass; Jurjen W Westra; Ewan Hunter; Alexandre Akoulitchev; Alun G Williams Journal: Genes (Basel) Date: 2020-08-07 Impact factor: 4.096