Cargando…
Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men
Purpose: The main objective of this study was to investigate the physiological effects of repetitive diving-induced hyperoxic conditions at 1.35 atmospheres absolute (ATA) on neuromuscular strength performance. We hypothesized that following five days of consecutive, resting, long-duration (6 h or m...
Autores principales: | , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Frontiers Media S.A.
2019
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6684734/ https://www.ncbi.nlm.nih.gov/pubmed/31417421 http://dx.doi.org/10.3389/fphys.2019.00960 |
_version_ | 1783442295863902208 |
---|---|
author | Myers, Christopher M. Kim, Jeong-Su Florian, John P. |
author_facet | Myers, Christopher M. Kim, Jeong-Su Florian, John P. |
author_sort | Myers, Christopher M. |
collection | PubMed |
description | Purpose: The main objective of this study was to investigate the physiological effects of repetitive diving-induced hyperoxic conditions at 1.35 atmospheres absolute (ATA) on neuromuscular strength performance. We hypothesized that following five days of consecutive, resting, long-duration (6 h or more) hyperoxic water immersions (WIs) neuromuscular strength performance would be reduced with a longer recovery time in comparison to previously reported normoxic WIs. Methods: Thirteen (n = 13) active male divers [31.3 ± 1.7 (24–43) years, mean ± years] completed five consecutive days of 6-h resting WIs with 18-h surface intervals while breathing 100% O(2) (n = 13) at 1.35 ATA. Skeletal muscle performance assessments occurred immediately before and after each WI and 24 and 72 h after the final WI. Performance assessments included maximum voluntary isometric contraction (MVIC) and maximal isokinetic (IK) knee extensions and elbow flexions, and isometric maximum handgrip (MHG) strength. Neuromuscular activation was also measured on the quadriceps, biceps brachii, and brachioradialis via surface electromyography (sEMG). Results: MHG declined by 7.8% (p < 0.001) by WI 5 with performance returning to baseline by 24-h post-WI. Brachioradialis neuromuscular activation increased by 42% on WI 5. MVIC knee extension performance dropped by 4% (p = 0.001) on WI 3 with a 11% overall decrease in quadriceps neuromuscular activation. Maximal IK knee extension dropped by 3.3% on WI 5 with 9% drop in overall quadriceps activation during the same period. MVIC elbow flexion declined by 5.1% on WI 5 but returned to baseline by 72-h post-WI. Maximal IK elbow flexion performance dropped by 8.6% on WI 5 with a continual decline in biceps brachii neuromuscular activation of 24% on WI 5. Conclusion: Consecutive, resting, long-duration hyperoxic WIs reduce muscular performance in multiple muscle groups and alter neuromuscular activation after 3 days of WI with performance adaptations recovering toward baseline by the end of the WI 5. However, neuromuscular activation remains decreased and appears to last beyond the 72-h post-WI recovery period. |
format | Online Article Text |
id | pubmed-6684734 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | Frontiers Media S.A. |
record_format | MEDLINE/PubMed |
spelling | pubmed-66847342019-08-15 Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men Myers, Christopher M. Kim, Jeong-Su Florian, John P. Front Physiol Physiology Purpose: The main objective of this study was to investigate the physiological effects of repetitive diving-induced hyperoxic conditions at 1.35 atmospheres absolute (ATA) on neuromuscular strength performance. We hypothesized that following five days of consecutive, resting, long-duration (6 h or more) hyperoxic water immersions (WIs) neuromuscular strength performance would be reduced with a longer recovery time in comparison to previously reported normoxic WIs. Methods: Thirteen (n = 13) active male divers [31.3 ± 1.7 (24–43) years, mean ± years] completed five consecutive days of 6-h resting WIs with 18-h surface intervals while breathing 100% O(2) (n = 13) at 1.35 ATA. Skeletal muscle performance assessments occurred immediately before and after each WI and 24 and 72 h after the final WI. Performance assessments included maximum voluntary isometric contraction (MVIC) and maximal isokinetic (IK) knee extensions and elbow flexions, and isometric maximum handgrip (MHG) strength. Neuromuscular activation was also measured on the quadriceps, biceps brachii, and brachioradialis via surface electromyography (sEMG). Results: MHG declined by 7.8% (p < 0.001) by WI 5 with performance returning to baseline by 24-h post-WI. Brachioradialis neuromuscular activation increased by 42% on WI 5. MVIC knee extension performance dropped by 4% (p = 0.001) on WI 3 with a 11% overall decrease in quadriceps neuromuscular activation. Maximal IK knee extension dropped by 3.3% on WI 5 with 9% drop in overall quadriceps activation during the same period. MVIC elbow flexion declined by 5.1% on WI 5 but returned to baseline by 72-h post-WI. Maximal IK elbow flexion performance dropped by 8.6% on WI 5 with a continual decline in biceps brachii neuromuscular activation of 24% on WI 5. Conclusion: Consecutive, resting, long-duration hyperoxic WIs reduce muscular performance in multiple muscle groups and alter neuromuscular activation after 3 days of WI with performance adaptations recovering toward baseline by the end of the WI 5. However, neuromuscular activation remains decreased and appears to last beyond the 72-h post-WI recovery period. Frontiers Media S.A. 2019-07-31 /pmc/articles/PMC6684734/ /pubmed/31417421 http://dx.doi.org/10.3389/fphys.2019.00960 Text en Copyright © 2019 Myers, Kim and Florian. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. |
spellingShingle | Physiology Myers, Christopher M. Kim, Jeong-Su Florian, John P. Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title | Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title_full | Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title_fullStr | Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title_full_unstemmed | Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title_short | Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men |
title_sort | consecutive, resting, long-duration hyperoxic exposures alter neuromuscular responses during maximal strength exercises in trained men |
topic | Physiology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6684734/ https://www.ncbi.nlm.nih.gov/pubmed/31417421 http://dx.doi.org/10.3389/fphys.2019.00960 |
work_keys_str_mv | AT myerschristopherm consecutiverestinglongdurationhyperoxicexposuresalterneuromuscularresponsesduringmaximalstrengthexercisesintrainedmen AT kimjeongsu consecutiverestinglongdurationhyperoxicexposuresalterneuromuscularresponsesduringmaximalstrengthexercisesintrainedmen AT florianjohnp consecutiverestinglongdurationhyperoxicexposuresalterneuromuscularresponsesduringmaximalstrengthexercisesintrainedmen |