Effects of repeated long-duration water immersions on skeletal muscle performance in well-trained male divers

Myers, Christopher M.; Kim, Jeong‐Su; Florian, John P.

doi:10.1007/s00421-018-3928-6

Cited by 6 publications

(39 citation statements)

References 25 publications

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“…Skeletal neuromuscular performance alterations following repeated long-duration WIs, such as those experienced by military, commercial, and technical divers, with exposures longer than 6 h at 1.35 ATA, are not well understood. Data from previous research suggest that these types of exposures are comparable to those seen in microgravity environments ( Myers et al, 2017 ). Short and long-term exposures to microgravity analogs are known to alter skeletal neuromuscular performance in weight and non-weight bearing muscle groups, also known as load- and non-load bearing muscles.…”

Section: Introductionmentioning

confidence: 57%

“…This result illustrates the difference between maximal and submaximal exertion that occurs with quadriceps performance when exposed to consecutive, long-duration WIs. Previously, we reported an 11% and 5% increase post-WI than pre-WI maximal isokinetic exercise on WIs 3 and 5 ( Myers et al, 2017 ). Furthermore, overall performance increased by 3% throughout the dive week.…”

Section: Discussionmentioning

confidence: 75%

“…Our previous studies using long-duration WIs have demonstrated decrements to muscular strength after 3 days with full recovery by 72-h after the last exposure ( Myers et al, 2017 ). However, little is still known about the effects of these types of exposures on load- versus non-load bearing muscular endurance as only handgrip endurance was investigated ( Florian et al, 2013b , 2014 ).…”

Section: Introductionmentioning

confidence: 96%

“…Water immersion, complete submersion of the body in water, alters physiological function during and after water egress ( Florian et al, 2013a , b , 2014 ; Myers et al, 2017 ). Skeletal neuromuscular performance alterations following repeated long-duration WIs, such as those experienced by military, commercial, and technical divers, with exposures longer than 6 h at 1.35 ATA, are not well understood.…”

Section: Introductionmentioning

confidence: 99%

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Effects of Resting, Consecutive, Long-Duration Water Immersions on Neuromuscular Endurance in Well-Trained Males

et al. 2018

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Purpose: This study examined the effects of repeated long-duration water immersions (WI)s at 1.35 atmospheres absolute (ATA) on neuromuscular endurance performance. We hypothesized that, following 5 days of consecutive, resting, long-duration WIs, neuromuscular endurance performance would decrease.Methods: Fifteen well-trained, male subjects completed five consecutive 6-h resting WIs with 18-h surface intervals during the dive week while breathing compressed air at 1.35 ATA. Skeletal muscle endurance performance was assessed before and after each WI, and 24 and 72 h after the final WI. Muscular endurance assessments included 40% maximum handgrip endurance (MHE) and 50-repetition maximal isokinetic knee extensions. Near infrared spectroscopy was used to measure muscle oxidative capacity of the vastus lateralis and localized muscle tissue oxygenation of the vastus lateralis and flexor carpi radialis. Simultaneously, brachioradialis neuromuscular activation was measured by surface electromyography.Results: A 24.9% increase (p = 0.04) in the muscle oxidative capacity rate constant (k) occurred on WI 4 compared to baseline. No changes occurred in 40% MHE time to exhaustion or rate of fatigue or total work performed for the 50-repetition maximal isokinetic knee extension. The first quartile of deoxygenated hemoglobin concentration showed a 6 and 35% increase on WIs 3 and 5 (p = 0.026) with second quartile increases of 9 and 32% on WIs 3 and 5 (p = 0.049) during the 40% MHE testing when compared to WI 1.Conclusion: Our specific WI protocol resulted in no change to muscular endurance and oxygen kinetics in load bearing and non-load bearing muscles.

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Section: Introductionmentioning

confidence: 57%

Section: Discussionmentioning

confidence: 75%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

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Effects of Resting, Consecutive, Long-Duration Water Immersions on Neuromuscular Endurance in Well-Trained Males

et al. 2018

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“…Military, commercial, and technical divers are exposed to elevated hydrostatic pressures for extended periods, typically up to 6 h (Florian et al, 2016). The increased hydrostatic pressure and mechanical unloading during water immersion (WI) alter physiological function and may adversely impact physical performance after water egress (Myers et al, 2018). Furthermore, 100% oxygen may be used as the inspired gas to prevent nitrogen narcosis or mitigate the need for decompression (Brubakk et al, 2003).…”

Section: Introductionmentioning

confidence: 99%

Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men

2019

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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.

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The Nutrition Domain

Myers,

Foley

2023

The Human Weapon System

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Effects of repeated long-duration water immersions on skeletal muscle performance in well-trained male divers

Abstract: Our findings indicate that repeated WIs caused noticeable decrements in neuromuscular activation and performance of load bearing muscles on WI 3 while full recovery was observed by 72-h post-WI.

Cited by 6 publications

References 25 publications

Effects of Resting, Consecutive, Long-Duration Water Immersions on Neuromuscular Endurance in Well-Trained Males

Effects of Resting, Consecutive, Long-Duration Water Immersions on Neuromuscular Endurance in Well-Trained Males

Consecutive, Resting, Long-Duration Hyperoxic Exposures Alter Neuromuscular Responses During Maximal Strength Exercises in Trained Men

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