Neuromuscular recovery from severe- and extreme-intensity exercise in men and women

2022 ◽  
Author(s):  
Andrew M Alexander ◽  
Shane M Hammer ◽  
Kaylin D Didier ◽  
Lillie M Huckaby ◽  
Thomas J. Barstow
Keyword(s):  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Partial Recovery ◽  
Men And Women ◽  
Task Failure ◽  
Isometric Knee Extension ◽  
Severe Intensity ◽  
Time Courses ◽  
Knee Extension Exercise

Maximal voluntary contraction force (MVC), potentiated twitch force (Qpot), and voluntary activation (%VA) recover to baseline within 90s following extreme-intensity exercise. However, methodological limitations masked important recovery kinetics. We hypothesized reductions in MVC, Qpot, and %VA at task failure following extreme-intensity exercise would be less than following severe-intensity exercise, and Qpot and MVC following extreme-intensity exercise would show significant recovery within 120s but remain depressed following severe-intensity exercise. Twelve subjects (6 men) completed two severe-intensity (40, 50%MVC) and two extreme-intensity (70, 80%MVC) isometric knee-extension exercise bouts to task failure (Tlim). Neuromuscular function was measured at baseline, Tlim, and through 150s of recovery. Each intensity significantly reduced MVC and Qpot compared to baseline. MVC was greater at T¬lim (p<0.01) and at 150s of recovery (p=0.004) following exercise at 80%MVC compared to severe-intensity exercise. Partial recovery of MVC and Qpot were detected within 150s following Tlim for each exercise intensity; Qpot recovered to baseline values within 150s of recovery following exercise at 80%MVC. No differences in %VA were detected pre- to post-exercise or across recovery for any intensity. Although further analysis showed sex-specific differences in MVC and Qpot, future studies should closely examine sex-dependent responses to extreme-intensity exercise. It is clear, however, that these data reinforce that mechanisms limiting exercise tolerance during extreme-intensity exercise recover quickly. NOVELTY: •Severe- and extreme-intensity exercise cause independent responses in fatigue accumulation and the subsequent recovery time courses. •Recovery of MVC and Qpot occurs much faster following extreme-intensity exercise in both men and women.

scholarly journals Stressor-induced increase in muscle fatigability of young men and women is predicted by strength but not voluntary activation

2014 ◽  
Vol 116 (7) ◽  
pp. 767-778 ◽  
Author(s):  
Manda L. Keller-Ross ◽  
Hugo M. Pereira ◽  
Jaclyn Pruse ◽  
Tejin Yoon ◽  
Bonnie Schlinder-DeLap ◽  
...  
Keyword(s):  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Men And Women ◽  
Task Failure ◽  
Initial Strength ◽  
Math Task ◽  
Flexor Muscles ◽  
Elbow Flexor Muscles ◽  
Induced Changes ◽  
And Control

This study investigated mechanisms for the stressor-induced changes in muscle fatigability in men and women. Participants performed an isometric-fatiguing contraction at 20% maximal voluntary contraction (MVC) until failure with the elbow flexor muscles. Study one ( n = 55; 29 women) involved two experimental sessions: 1) a high-stressor session that required a difficult mental-math task before and during a fatiguing contraction and 2) a control session with no mental math. For some participants (n = 28; 14 women), cortical stimulation was used to examine mechanisms that contributed to muscle fatigability during the high-stressor and control sessions. Study two ( n = 23; nine women) determined the influence of a low stressor, i.e., a simple mental-math task, on muscle fatigability. In study one, the time-to-task failure was less for the high-stressor session than control ( P < 0.05) for women (19.4%) and men (9.5%): the sex difference response disappeared when covaried for initial strength (MVC). MVC force, voluntary activation, and peak-twitch amplitude decreased similarly for the control and high-stressor sessions ( P < 0.05). In study two, the time-to-task failure of men or women was not influenced by the low stressor ( P > 0.05). The greater fatigability, when exposed to a high stressor during a low-force task, was not exclusive to women but involved a strength-related mechanism in both weaker men and women that accelerated declines in voluntary activation and slowing of contractile properties.

Initial phase of maximal voluntary and electrically stimulated knee extension torque development at different knee angles

2004 ◽  
Vol 97 (5) ◽  
pp. 1693-1701 ◽  
Author(s):  
C. J. de Ruiter ◽  
R. D. Kooistra ◽  
M. I. Paalman ◽  
A. de Haan
Keyword(s):  
Muscle Activation ◽  
Knee Extensor ◽  
Surface Emg ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Knee Angle ◽  
Time Integral ◽  
Voluntary Contractions ◽  
Torque Development

We investigated the capacity for torque development and muscle activation at the onset of fast voluntary isometric knee extensions at 30, 60, and 90° knee angle. Experiments were performed in subjects ( n = 7) who had high levels (>90%) of activation at the plateau of maximal voluntary contractions. During maximal electrical nerve stimulation (8 pulses at 300 Hz), the maximal rate of torque development (MRTD) and torque time integral over the first 40 ms (TTI40) changed in proportion with torque at the different knee angles (highest values at 60°). At each knee angle, voluntary MRTD and stimulated MRTD were similar ( P < 0.05), but time to voluntary MRTD was significantly longer. Voluntary TTI40 was independent ( P > 0.05) of knee angle and on average (all subjects and angles) only 40% of stimulated TTI40. However, among subjects, the averaged (across knee angles) values ranged from 10.3 ± 3.1 to 83.3 ± 3.2% and were positively related ( r2 = 0.75, P < 0.05) to the knee-extensor surface EMG at the start of torque development. It was concluded that, although all subjects had high levels of voluntary activation at the plateau of maximal voluntary contraction, among subjects and independent of knee angle, the capacity for fast muscle activation varied substantially. Moreover, in all subjects, torque developed considerably faster during maximal electrical stimulation than during maximal voluntary effort. At different knee angles, stimulated MRTD and TTI40 changed in proportion with stimulated torque, but voluntary MRTD and TTI40 changed less than maximal voluntary torque.

scholarly journals Acute effect of tendon vibration applied during isometric contraction at two knee angles on maximal knee extension force production

PLoS ONE ◽  
2020 ◽  
Vol 15 (11) ◽  
pp. e0242324
Author(s):  
Jonathan Harnie ◽  
Thomas Cattagni ◽  
Christophe Cornu ◽  
Peter McNair ◽  
Marc Jubeau
Keyword(s):  
Isometric Contraction ◽  
Vastus Lateralis ◽  
Force Production ◽  
Knee Extensor ◽  
Acute Effect ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Tendon Vibration ◽  
Knee Angle

The aim of the current study was to investigate the effect of a single session of prolonged tendon vibration combined with low submaximal isometric contraction on maximal motor performance. Thirty-two young sedentary adults were assigned into two groups that differed based on the knee angle tested: 90° or 150° (180° = full knee extension). Participants performed two fatigue-inducing exercise protocols: one with three 10 min submaximal (10% of maximal voluntary contraction) knee extensor contractions and patellar tendon vibration (80 Hz) another with submaximal knee extensor contractions only. Before and after each fatigue protocol, maximal voluntary isometric contractions (MVC), voluntary activation level (assessed by the twitch interpolation technique), peak-to-peak amplitude of maximum compound action potentials of vastus medialis and vastus lateralis (assessed by electromyography with the use of electrical nerve stimulation), peak twitch amplitude and peak doublet force were measured. The knee extensor fatigue was significantly (P<0.05) greater in the 90° knee angle group (-20.6% MVC force, P<0.05) than the 150° knee angle group (-8.3% MVC force, P = 0.062). Both peripheral and central alterations could explain the reduction in MVC force at 90° knee angle. However, tendon vibration added to isometric contraction did not exacerbate the reduction in MVC force. These results clearly demonstrate that acute infrapatellar tendon vibration using a commercial apparatus operating at optimal conditions (i.e. contracted and stretched muscle) does not appear to induce knee extensor neuromuscular fatigue in young sedentary subjects.

scholarly journals Active hyperemia and vascular conductance differ between men and women for an isometric fatiguing contraction

2006 ◽  
Vol 101 (1) ◽  
pp. 140-150 ◽  
Author(s):  
Sandra K. Hunter ◽  
Jennie M. Schletty ◽  
Kristine M. Schlachter ◽  
Erin E. Griffith ◽  
Aaron J. Polichnowski ◽  
...  
Keyword(s):  
Blood Flow ◽  
Venous Occlusion ◽  
Voluntary Contraction ◽  
Time To Failure ◽  
Vascular Conductance ◽  
Similar Time ◽  
Men And Women ◽  
Task Failure ◽  
Target Force

To understand the role of muscle perfusion in the sex differences of muscle fatigue, we compared the time to task failure, postcontraction (active) hyperemia, and vascular conductance for an isometric fatiguing contraction performed by young men and women with the handgrip muscles at 20% of maximal voluntary contraction (MVC) force. In study 1, the men ( n = 16) were stronger than the women ( n = 18), and study 2, the men ( n = 7) and women ( n = 7) were matched for strength. Isometric contractions were sustained during two sessions: 1) until the target force could no longer be achieved or 2) for 4 min. For both studies, blood flow and vascular conductance were similar for the men and women at rest and after 10 min of occlusion, and at task failure for the fatiguing contraction estimated using forearm venous occlusion plethysmography. In study 1, the time to task failure was longer for the women (11.4 ± 2.8 min) than for the men (8.4 ± 2.4 min; P = 0.003). However, at the end of the 4-min contraction, active hyperemia and vascular conductance were greater for the men than the women (99 vs. 70% peak blood flow; P < 0.001). In study 2, the men and women had similar strength and a similar time to failure (8.4 ± 1.6 vs. 8.6 ± 2.3 min). Active hyperemia was greater for the men than the women (86 vs. 64% peak flow; P = 0.038) after the 4-min contraction, as was vascular conductance (80 vs. 57% peak conductance; P = 0.02). Thus the briefer time to failure of men than women for an isometric fatiguing contraction is a function of the greater strength of men but is not dependent on differences in the active hyperemia and vascular conductance.

scholarly journals Hyperthermia and central fatigue during prolonged exercise in humans

2001 ◽  
Vol 91 (3) ◽  
pp. 1055-1060 ◽  
Author(s):  
Lars Nybo ◽  
Bodil Nielsen
Keyword(s):  
Core Temperature ◽  
Maximal Oxygen Consumption ◽  
Knee Extensor ◽  
Central Fatigue ◽  
Knee Extension ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Total Force ◽  
Impaired Performance

The present study investigated the effects of hyperthermia on the contributions of central and peripheral factors to the development of neuromuscular fatigue. Fourteen men exercised at 60% maximal oxygen consumption on a cycle ergometer in hot (40°C; hyperthermia) and thermoneutral (18°C; control) environments. In hyperthermia, the core temperature increased throughout the exercise period and reached a peak value of 40.0 ± 0.1°C (mean ± SE) at exhaustion after 50 ± 3 min of exercise. In control, core temperature stabilized at ∼38.0 ± 0.1°C, and exercise was maintained for 1 h without exhausting the subjects. Immediately after the cycle trials, subjects performed 2 min of sustained maximal voluntary contraction (MVC) either with the exercised legs (knee extension) or with a “nonexercised” muscle group (handgrip). The degree of voluntary activation during sustained maximal knee extensions was assessed by superimposing electrical stimulation (EL) to nervus femoralis. Voluntary knee extensor force was similar during the first 5 s of contraction in hyperthermia and control. Thereafter, force declined in both trials, but the reduction in maximal voluntary force was more pronounced in the hyperthermic trial, and, from 30 to 120 s, the force was significantly lower in hyperthermia compared with control. Calculation of the voluntary activation percentage (MVC/MVC + EL) revealed that the degree of central activation was significantly lower in hyperthermia (54 ± 7%) compared with control (82 ± 6%). In contrast, total force of the knee extensors (MVC + force from EL) was not different in the two trials. Force development during handgrip contraction followed the same pattern of response as was observed for the knee extensors. In conclusion, these data demonstrate that the ability to generate force during a prolonged MVC is attenuated with hyperthermia, and the impaired performance is associated with a reduction in the voluntary activation percentage.

Exercising muscle mass influences neuromuscular, cardiorespiratory, and perceptual responses during and following ramp incremental cycling to task failure

2021 ◽  
Author(s):  
Jenny Zhang ◽  
Danilo Iannetta ◽  
Mohammed Alzeeby ◽  
Martin J. MacInnis ◽  
Saied Jalal Aboodarda
Keyword(s):  
Muscle Mass ◽  
Perceived Exertion ◽  
Central Fatigue ◽  
Exercise Duration ◽  
Peak Oxygen Uptake ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Peak Power Output ◽  
Task Failure ◽  
Single Twitch

Neuromuscular (NM), cardiorespiratory, and perceptual responses to maximal graded exercise using different amounts of active muscle mass remain unclear. We hypothesized that during dynamic exercise, peripheral NM fatigue (declined twitch force) and muscle pain would be greater using smaller muscle mass, whereas central fatigue (declined voluntary activation) and ventilatory variables would be greater using larger muscle mass. Twelve males (29.8±4.7 years) performed two cycling ramp incremental tests until task failure: (i) single-leg (SL) with 10 W·min-1ramp, and (ii) double-leg (DL) with 20 W·min-1ramp. NM fatigue was assessed at baseline, task failure (post), then after 1, 4, and 8 min of recovery. Cardiorespiratory and perceptual variables (i.e., ratings of perceived exertion (RPE), fatigue, pain, dyspnea) were measured throughout cycling. Exercise duration was similar between sessions (SL: 857.7±263.6; DL: 855.0±218.8 s; p=0.923) and higher absolute peak power output was attained in DL (SL: 163.2±43.8; DL: 307.0±72.0 W; p<0.001). While central fatigue did not differ between conditions (SL: -6.6±6.5%; DL: -3.5±4.8%; p=0.091), maximal voluntary contraction (SL: -41.6±10.9%; DL: -33.7±8.5%; p=0.032) and single twitch forces (SL: -59.4±18.8%; DL: -46.2±16.2%; p=0.003) declined more following SL. DL elicited higher peak oxygen uptake (SL: 42.1±10.0; DL:50.3±9.3 mL·kg-1·min-1; p<0.001), ventilation (SL: 137.1±38.1; DL: 171.5±33.2 L·min-1; p<0.001), and heart rate (SL: 167±21; DL: 187±8 bpm; p=0.005). Dyspnea (p=0.025) was higher in DL; however, RPE (p=0.005) and pain (p<0.001) were higher in SL. These results suggest that interplay between NM, cardiorespiratory, and perceptual determinants of exercise performance during incremental cycling to task failure are muscle mass-dependent.

Comparison of neuromuscular adjustments associated with sustained isometric contractions of four different muscle groups

2013 ◽  
Vol 114 (10) ◽  
pp. 1426-1434 ◽  
Author(s):  
Daria Neyroud ◽  
Jennifer Rüttimann ◽  
Anne F. Mannion ◽  
Guillaume Y. Millet ◽  
Nicola A. Maffiuletti ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Upper Limb ◽  
Voluntary Contraction ◽  
Voluntary Activation ◽  
Knee Extensors ◽  
Elbow Flexors ◽  
Plantar Flexors ◽  
Task Failure ◽  
Before And After ◽  
Muscle Groups

The extent and characteristics of muscle fatigue of different muscle groups when subjected to a similar fatiguing task may differ. Thirteen healthy young men performed sustained contractions at 50% maximal voluntary contraction (MVC) force until task failure, with four different muscle groups, over two sessions. Per session, one upper limb and one lower limb muscle group were tested (knee extensors and thumb adductor, or plantar and elbow flexors). Changes in voluntary activation level and contractile properties were derived from doublet responses evoked during and after MVCs before and after exercise. Time to task failure differed ( P < 0.05) between muscle groups (220 ± 64 s for plantar flexors, 114 ± 27 s for thumb adductor, 77 ± 25 s for knee extensors, and 72 ± 14 s for elbow flexors). MVC force loss immediately after voluntary task failure was similar (−30 ± 11% for plantar flexors, −37 ± 13% for thumb adductor, −34 ± 15% for knee extensors, and −40 ± 12% for elbow flexors, P > 0.05). Voluntary activation was decreased for plantar flexors only (from 95 ± 5% to 82 ± 9%, P < 0.05). Potentiated evoked doublet amplitude was more depressed for upper limb muscles (−59.3 ± 14.7% for elbow flexors and −60.1 ± 24.1% for thumb adductor, P < 0.05) than for knee extensors (−28 ± 15%, P < 0.05); no reduction was found in plantar flexors (−7 ± 12%, P > 0.05). In conclusion, despite different times to task failure when sustaining an isometric contraction at 50% MVC force for as long as possible, diverse muscle groups present similar loss of MVC force after task failure. Thus the extent of muscle fatigue is not affected by time to task failure, whereas this latter determines the etiology of fatigue.

scholarly journals Global and regional left ventricular circumferential strain during incremental cycling and isometric knee extension exercise

2018 ◽  
Vol 35 (8) ◽  
pp. 1149-1156
Author(s):  
Alexander Beaumont ◽  
Nicholas Sculthorpe ◽  
John Hough ◽  
Viswanath Unnithan ◽  
Joanna Richards
Keyword(s):  
Circumferential Strain ◽  
Knee Extension ◽  
Left Ventricular ◽  
Isometric Knee Extension ◽  
Knee Extension Exercise

scholarly journals Sex differences in response to cognitive stress during a fatiguing contraction

2009 ◽  
Vol 107 (5) ◽  
pp. 1486-1496 ◽  
Author(s):  
Tejin Yoon ◽  
Manda L. Keller ◽  
Bonnie Schlinder De-Lap ◽  
April Harkins ◽  
Romuald Lepers ◽  
...  
Keyword(s):  
Voluntary Contraction ◽  
Rate Pressure Product ◽  
Men And Women ◽  
Cognitive Stress ◽  
Task Failure ◽  
Initial Strength ◽  
Flexor Muscles ◽  
Target Force ◽  
Cognitive Stressor ◽  
And Control

This study compared the time to task failure for a submaximal fatiguing contraction in the presence and absence of a cognitive stressor in men and women. In study 1, 10 men and 10 women (22 ± 3 yr of age) performed an isometric fatiguing contraction at 20% maximal voluntary contraction force until task failure with the elbow flexor muscles during two separate sessions. Subjects performed a mental-math task during one of the fatiguing contractions that aimed to increase anxiety and stress (stressor session). Salivary cortisol and reported levels of arousal (visual analog scale for anxiety, and State-Trait Anxiety Inventory scores) were elevated during the stressor session compared with a control session for both sexes ( P < 0.05). Time to task failure, however, was briefer during the stressor session compared with control ( P = 0.005) but more so for the women (27.3 ± 20.1%) than the men (8.6 ± 23.1%) ( P = 0.03). The briefer time to task failure was associated with target force ( r2 = 0.21) and accompanied by a higher mean arterial pressure, heart rate, and rate-pressure product during the fatiguing contraction in the stressor session compared with control in women. In study 2 (11 men and 8 women, 20 ± 3 yr of age), time to task failure was similar for a fatiguing contraction with simple mental-math that did not increase stress (mental-attentiveness session) and control for both men and women. The greater change in fatigability of women than men with performance of a cognitive stressor involved initial strength and increases in indexes of sympathetic neural activity and cardiac work compared with control conditions.

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