ArticleHigh altitude medicine & biology2014
Muscle activation during exercise in severe acute hypoxia: role of absolute and relative intensity.
Article in High altitude medicine & biology, 2014. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 13 papers.
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Who cites it
13 citing papers in PubMed, 28 citations in OpenAlex.
- Effect of hypoxia on muscle activation at equivalent absolute and relative intensity during incremental and constant load exercise to task failure.Experimental physiology · 2026Article
- Non-invasive motor unit analysis reveals specific responses during maximal muscle contraction under normobaric hypoxia.Pflugers Archiv : European journal of physiology · 2025Article
- Comments on: Electromyographic signature of isometric squat in the highest refuge in Europe.European journal of translational myology · 2023Article
- Electromyographic signature of isometric squat in the highest refuge in Europe.European journal of translational myology · 2023Article
- Neuromuscular and Muscle Tissue Hemodynamic Responses When Exposed to Normobaric Hypoxia during Lower-Body Fatiguing Muscle Actions.Journal of musculoskeletal & neuronal interactions · 2023Article
- Neuromuscular responses at acute moderate and severe hypoxic exposure during fatiguing exercise of the biceps brachii.Current research in physiology · 2021Article
- The plateau in the NIRS-derived [HHb] signal near the end of a ramp incremental test does not indicate the upper limit of OAmerican journal of physiology. Regulatory, integrative and comparative physiology · 2017Article
- The Physiological Mechanisms of Performance Enhancement with Sprint Interval Training Differ between the Upper and Lower Extremities in Humans.Frontiers in physiology · 2016Article
- Increased PIO2 at Exhaustion in Hypoxia Enhances Muscle Activation and Swiftly Relieves Fatigue: A Placebo or a PIO2 Dependent Effect?Frontiers in physiology · 2016Article
- What limits performance during whole-body incremental exercise to exhaustion in humans?The Journal of physiology · 2015Article
- Limitations to oxygen transport and utilization during sprint exercise in humans: evidence for a functional reserve in muscle O2 diffusing capacity.The Journal of physiology · 2015Article
- Task Failure during Exercise to Exhaustion in Normoxia and Hypoxia Is Due to Reduced Muscle Activation Caused by Central Mechanisms While Muscle Metaboreflex Does Not Limit Performance.Frontiers in physiology · 2015Article
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Corrections and comments
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Authors and funding
7 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The aim of this study was to determine the influence of severe acute hypoxia on muscle activation during whole body dynamic exercise. Eleven young men performed four incremental cycle ergometer tests to exhaustion breathing normoxic (FIO2=0.21, two tests) or hypoxic gas (FIO2=0.108, two tests). Surface electromyography (EMG) activities of rectus femoris (RF), vastus medialis (VL), vastus lateralis (VL), and biceps femoris (BF) were recorded. The two normoxic and the two hypoxic tests were averaged to reduce EMG variability. Peak VO2 was 34% lower in hypoxia than in normoxia (p<0.05). The EMG root mean square (RMS) increased with exercise intensity in all muscles (p<0.05), with greater effect in hypoxia than in normoxia in the RF and VM (p<0.05), and a similar trend in VL (p=0.10). At the same relative intensity, the RMS was greater in normoxia than in hypoxia in RF, VL, and BF (p<0.05), with a similar trend in VM (p=0.08). Median frequency increased with exercise intensity (p<0.05), and was higher in hypoxia than in normoxia in VL (p<0.05). Muscle contraction burst duration increased with exercise intensity in VM and VL (p<0.05), without clear effects of FIO2. No significant FIO2 effects on frequency domain indices were observed when compared at the same relative intensity. In conclusion, muscle activation during whole body exercise increases almost linearly with exercise intensity, following a muscle-specific pattern, which is adjusted depending on the FIO2 and the relative intensity of exercise. Both VL and VM are increasingly involved in power output generation with the increase of intensity and the reduction in FIO2.
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