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Mira J, Brownstein CG, Kennouche D, Varesco G, Roma E, Lapole T, Millet GY. Reliability of Corticospinal and Motoneuronal Excitability Evaluation during Unfatiguing and Fatiguing Cycling Exercise. Med Sci Sports Exerc 2024; 56:1849-1859. [PMID: 38619970 DOI: 10.1249/mss.0000000000003465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
INTRODUCTION Central nervous system excitability depends on the task performed, muscle group solicited, and contraction type. However, little is known on corticospinal and motoneuronal excitability measured during locomotor exercise. This study aimed at determining the reliability of motor-evoked potentials (MEP) and thoracic motor-evoked potentials (TMEP) in dynamic mode during unfatiguing and fatiguing cycling exercise. METHODS Twenty-two participants completed four visits. Visit 1 comprised familiarization and an incremental cycling test to determine maximal power output ( Wmax ). The remaining visits encompassed unfatiguing evaluations, which included a total of eight brief bouts of moderate- (50% Wmax ) and high-intensity cycling (80% Wmax ), four at each intensity. In each bout, a set of two TMEPs, five MEPs, and one M-max were obtained. Subsequently, a fatiguing exercise to exhaustion at 80% Wmax was performed, with four sets of measurements 3 min through the exercise and four additional sets at exhaustion, both measured at 50% Wmax . RESULTS Intraclass correlation coefficients (ICCs) for 5, 10, 15, and 20 MEP·Mmax -1 revealed excellent reliability at both intensities and during cycling to exhaustion (ICC ≥0.92). TMEP·Mmax -1 showed ICCs ≥0.82 for moderate and high intensity, and it was not affected by fatigability. Overall standard error of measurement was 0.090 (0.083, 0.097) for MEP·Mmax -1 and 0.114 (0.105, 0.125) for TMEP·Mmax -1 . A systematic bias associated with the number of stimulations, especially at high intensity, suggested that the evaluation itself may be influenced by fatigability. A mean reduction of 8% was detected in TMEP·Mmax -1 at exhaustion. CONCLUSIONS Motoneuronal and corticospinal excitability measured in dynamic mode presented good to excellent reliability in unfatiguing and fatiguing exercise. Further studies inducing greater fatigability must be conducted to assess the sensitivity of central nervous system excitability during cycling.
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Affiliation(s)
- José Mira
- Université Jean Monnet Saint-Etienne, Lyon 1, Université Savoie Mont-Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, F-42023, Saint-Etienne, France
| | - Callum G Brownstein
- School of Biomedical, Nutritional, and Sport Sciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UNITED KINGDOM
| | - Djahid Kennouche
- Université Jean Monnet Saint-Etienne, Lyon 1, Université Savoie Mont-Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, F-42023, Saint-Etienne, France
| | - Giorgio Varesco
- Nantes Université, Laboratory Movement - Interactions - Performance (MIP), UR 4334, F-44000 Nantes, France
| | - Enrico Roma
- Université Jean Monnet Saint-Etienne, Lyon 1, Université Savoie Mont-Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, F-42023, Saint-Etienne, France
| | - Thomas Lapole
- Université Jean Monnet Saint-Etienne, Lyon 1, Université Savoie Mont-Blanc, Laboratoire Interuniversitaire de Biologie de la Motricité, F-42023, Saint-Etienne, France
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Zhang J, McClean ZJ, Khaledi N, Morgan SJ, Millet GY, Aboodarda SJ. Reliability of transcranial magnetic stimulation-evoked responses on knee extensor muscles during cycling. Exp Brain Res 2024; 242:1681-1695. [PMID: 38806709 DOI: 10.1007/s00221-024-06859-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 05/19/2024] [Indexed: 05/30/2024]
Abstract
Transcranial magnetic stimulation (TMS) measures the excitability and inhibition of corticomotor networks. Despite its task-specificity, few studies have used TMS during dynamic movements and the reliability of TMS paired pulses has not been assessed during cycling. This study aimed to evaluate the reliability of motor evoked potentials (MEP) and short- and long-interval intracortical inhibition (SICI and LICI) on vastus lateralis and rectus femoris muscle activity during a fatiguing single-leg cycling task. Nine healthy adults (2 female) performed two identical sessions of counterweighted single-leg cycling at 60% peak power output until failure. Five single pulses and ten paired pulses were delivered to the motor cortex, and two maximal femoral nerve stimulations (Mmax) were administered during two baseline cycling bouts (unfatigued) and every 5 min throughout cycling (fatigued). When comparing both baseline bouts within the same session, MEP·Mmax-1 and LICI (both ICC: >0.9) were rated excellent while SICI was rated good (ICC: 0.7-0.9). At baseline, between sessions, in the vastus lateralis, Mmax (ICC: >0.9) and MEP·Mmax-1 (ICC: 0.7) demonstrated good reliability; LICI was moderate (ICC: 0.5), and SICI was poor (ICC: 0.3). Across the fatiguing task, Mmax demonstrated excellent reliability (ICC > 0.8), MEP·Mmax-1 ranged good to excellent (ICC: 0.7-0.9), LICI was moderate to excellent (ICC: 0.5-0.9), and SICI remained poorly reliable (ICC: 0.3-0.6). These results corroborate the cruciality of retaining mode-specific testing measurements and suggest that during cycling, Mmax, MEP·Mmax-1, and LICI measures are reliable whereas SICI, although less reliable across days, can be reliable within the same session.
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Affiliation(s)
- Jenny Zhang
- Faculty of Kinesiology, University of Calgary, KNB 420, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Zachary J McClean
- Faculty of Kinesiology, University of Calgary, KNB 420, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Neda Khaledi
- Faculty of Kinesiology, University of Calgary, KNB 420, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
- Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran
| | - Sophie-Jayne Morgan
- Faculty of Kinesiology, University of Calgary, KNB 420, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada
| | - Guillaume Y Millet
- Inter-university Laboratory of Human Movement Biology, Université Jean Monnet Saint-Etienne, Université Savoie Mont-Blanc, Lyon 1, Saint-Etienne, F-42023, France
| | - Saied Jalal Aboodarda
- Faculty of Kinesiology, University of Calgary, KNB 420, 2500 University Drive NW, Calgary, AB, T2N 1N4, Canada.
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Rocha JVDS, de Almeida RF, de Lima Cordeiro BN, Cardoso Sarcinelli CH, Zimerer C, Arêas FZ. Effects of bi-hemispheric anodal transcranial direct current stimulation on soccer player performance: a triple-blinded, controlled, and randomized study. Front Sports Act Living 2024; 6:1350660. [PMID: 38584685 PMCID: PMC10995377 DOI: 10.3389/fspor.2024.1350660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 02/27/2024] [Indexed: 04/09/2024] Open
Abstract
The search for increased performance and physical performance are linked to the use of ergogenic resources. The vertical jump is one of the measures commonly used to evaluate the performance of lower limbs in athletes. Transcranial direct current stimulation (tDCS) is a non-invasive, safe, economically viable technique that can modulate cortical excitability, which can influence the increase in the performance of athletes in general. This study aimed to investigate whether the use of tDCS on the primary motor cortex (M1) improves the performance of soccer players. A cross-sectional study was conducted. Twenty-seven players were randomized into three groups: Active tDCS group (n = 9), Sham group (n = 9), and control group (n = 9). Stimulation was applied at 2 mA for 15 min using a cephalic mount. Visual Pain Scale (VAS) and Subjective Recovery Scale (SRS) were monitored before and after tDCS. In addition, the participants performed the Countermovement Jump (CMJ) before and after the stimulation intercalated with Heart Rate (HR) and Rating of Perceived Exertion (RPE CR-10). No differences were found in any of the performance variables analyzed (p > 0.05) nor in the responses of HR (p > 0.05), RPE (p > 0.05), VAS (p > 0.05), and SRS (p > 0.05) between groups. The tDCS in M1 did not change the performance of the vertical jump, and there was no improvement in the subjective scales. New studies should also be developed with different stimulus intensities in different cortical areas and sports modalities.
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Affiliation(s)
- Jader Vinicius Da Silva Rocha
- Universidade Federal do Espirito Santo, Vitória, Brazil
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Brazil
| | | | - Bárbara Naeme de Lima Cordeiro
- Universidade Federal do Espirito Santo, Vitória, Brazil
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Brazil
| | | | - Carla Zimerer
- Universidade Federal do Espirito Santo, Vitória, Brazil
| | - Fernando Zanela Arêas
- Universidade Federal do Espirito Santo, Vitória, Brazil
- Department of Physiological Sciences, Federal University of Espirito Santo, Vitória, Brazil
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Amann M, Sidhu SK, McNeil CJ, Gandevia SC. Critical considerations of the contribution of the corticomotoneuronal pathway to central fatigue. J Physiol 2022; 600:5203-5214. [PMID: 36326193 PMCID: PMC9772161 DOI: 10.1113/jp282564] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Accepted: 10/31/2022] [Indexed: 11/06/2022] Open
Abstract
Neural drive originating in higher brain areas reaches exercising limb muscles through the corticospinal-motoneuronal pathway, which links the motor cortex and spinal motoneurones. The properties of this pathway have frequently been observed to change during fatiguing exercise in ways that could influence the development of central fatigue (i.e. the progressive reduction in voluntary muscle activation). However, based on differences in motor cortical and motoneuronal excitability between exercise modalities (e.g. single-joint vs. locomotor exercise), there is no characteristic response that allows for a categorical conclusion about the effect of these changes on functional impairments and performance limitations. Despite the lack of uniformity in findings during fatigue, there is strong evidence for marked 'inhibition' of motoneurones as a direct result of voluntary drive. Endogenous forms of neuromodulation, such as via serotonin released from neurones, can directly affect motoneuronal output and central fatigue. Exogenous forms of neuromodulation, such as brain stimulation, may achieve a similar effect, although the evidence is weak. Non-invasive transcranial direct current stimulation can cause transient or long-lasting changes in cortical excitability; however, variable results across studies cast doubt on its claimed capacity to enhance performance. Furthermore, with these studies, it is difficult to establish a cause-and-effect relationship between brain responsiveness and exercise performance. This review briefly summarizes changes in the corticomotoneuronal pathway during various types of exercise, and considers the relevance of these changes for the development of central fatigue, as well as the potential of non-invasive brain stimulation to enhance motor cortical excitability, motoneuronal output and, ultimately, exercise performance.
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Affiliation(s)
- Markus Amann
- Department of Anesthesiology, University of Utah, Salt Lake City, UT, USA
| | - Simranjit K. Sidhu
- School of Biomedicine, The University of Adelaide, South Australia, Australia
| | - Chris J McNeil
- School of Health and Exercise Sciences, University of British Columbia, Kelowna, BC, Canada
| | - Simon C Gandevia
- Neuroscience Research Australia and University of New South Wales, Sydney, Australia
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Comparison of Electroencephalogram Power Spectrum Characteristics of Left and Right Dragon Boat Athletes after 1 km of Rowing. Brain Sci 2022; 12:brainsci12121621. [PMID: 36552080 PMCID: PMC9776062 DOI: 10.3390/brainsci12121621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/29/2022] Open
Abstract
Purpose: This study aimed to detect differences in post-exercise brain activity between the left and right paddlers due to exercise by analyzing the resting-state electroencephalogram (EEG) power spectrum before and after exercise. Methods: Twenty-one right paddlers and twenty-two left paddlers completed a 1 km all-out test on a dragon boat ergometer, and their heart rate and exercise time were recorded. EEG signals were collected from superficial brain layers before and after exercise; then, the EEG power spectrum was extracted and compared in different frequency bands. In addition, the degree of lateralization in each brain region was assessed by the asymmetry index. Results: There was no significant difference in the power spectrum values and asymmetry indices between the left and right paddlers before rowing (p ˃ 0.05). However, after rowing, the left-paddlers group had significantly higher spectral power values in θ and α bands than the right-paddlers group (p < 0.05), and brain lateralization in both groups of athletes occurred mainly in the ipsilateral hemisphere of the frontal and central regions. Conclusion: The 1 km of rowing induced more brain activation in the left paddlers, and both left and right paddlers showed functional aggregation of hemispheric lateralization.
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Clos P, Mater A, Legrand H, Poirier G, Ballay Y, Martin A, Lepers R. Corticospinal Excitability Is Lower During Eccentric Than Concentric Cycling in Men. Front Physiol 2022; 13:854824. [PMID: 35370788 PMCID: PMC8966379 DOI: 10.3389/fphys.2022.854824] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/14/2022] [Indexed: 11/16/2022] Open
Abstract
How corticospinal excitability changes during eccentric locomotor exercise is unknown. In the present study, 13 volunteers performed 30-min strenuous concentric and eccentric cycling bouts at the same power output (60% concentric peak power output). Transcranial magnetic and electrical femoral nerve stimulations were applied at exercise onset (3rd min) and end (25th min). Motor-evoked potentials (MEPs) amplitude was measured for the rectus femoris (RF) and vastus lateralis (VL) muscles with surface electromyography (EMG) and expressed as a percentage of maximal M-wave amplitude (MMAX). EMG amplitude 100 ms prior to MEPs and the silent period duration were calculated. There was no change in any neural parameter during the exercises (all P > 0.24). VL and RF MMAX were unaffected by exercise modality (all P > 0.38). VL MEP amplitude was greater (26 ± 11.4 vs. 15.2 ± 7.7% MMAX; P = 0.008) during concentric than eccentric cycling whereas RF MEP amplitude was not different (24.4 ± 10.8 vs. 17.2 ± 9.8% MMAX; P = 0.051). While VL EMG was higher during concentric than eccentric cycling (P = 0.03), RF EMG showed no significant difference (P = 0.07). Similar silent period durations were found (RF: 120 ± 30 ms; VL: 114 ± 27 ms; all P > 0.61), but the silent period/MEP ratio was higher during eccentric than concentric cycling for both muscles (all P < 0.02). In conclusion, corticospinal excitability to the knee extensors is lower and relative silent period longer during eccentric than concentric cycling, yet both remained unaltered with time.
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Marshall PW, Forward T, Enoka RM. Fatigability of the knee extensors following high- and low-load resistance exercise sessions in trained men. Eur J Appl Physiol 2021; 122:245-254. [PMID: 34669044 DOI: 10.1007/s00421-021-04832-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 10/14/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE Fatigability after gym-based resistance exercises with high and low loads has not been well described, thus limiting the translation of exhaustive low-weight prescription into athletic practice. We compared the fatigability and recovery of the knee extensor muscles for up to 1H after sessions that involved either high- or low-load resistance exercises. METHODS 16 trained men performed two resistance exercise sessions between 5 and 7 days apart. The LIGHT session involved five sets to task failure at 50% of maximal knee-extension strength, whereas the HEAVY session accrued repetitions across seven sets at intensities ≥ 80% maximal knee-extension strength. Measures of quadriceps maximal torque and rate of torque development were measured before, after, and 1H after each exercise session. Muscle activation (electromyography and voluntary activation) and contractility were measured from doublet stimulation of the femoral nerve during and after maximal contractions, respectively. RESULTS Greater declines in maximal rate of torque development were observed after the LIGHT compared with the HEAVY session (p < 0.001), with full recovery after 1H. Voluntary activation (100-Hz doublet stimulation) and surface electromyograms were reduced immediately after the HEAVY session only (p < 0.05), with greater declines in quadriceps twitch amplitudes after the LIGHT session (p < 0.01). Voluntary activation (100-Hz doublet stimulation) was reduced at 1H after both the HEAVY and LIGHT sessions (p < 0.05). CONCLUSIONS Despite differences in the decreases in muscle activation and contractility after high- and low-load resistance-exercise sessions, recovery of neuromuscular function was essentially complete after 1H of rest for both sessions.
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Affiliation(s)
- Paul W Marshall
- Department of Exercise Sciences, University of Auckland, Building 907, Newmarket, 1023, Auckland, New Zealand. .,Human Performance Laboratory, School of Health Sciences, Western Sydney University, Penrith, Australia.
| | - Thomas Forward
- Human Performance Laboratory, School of Health Sciences, Western Sydney University, Penrith, Australia
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
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Ghorbani M, Clark CCT. Brain function during central fatigue induced by intermittent high-intensity cycling. Neurol Sci 2021; 42:3655-3661. [PMID: 33439390 DOI: 10.1007/s10072-020-04965-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 12/04/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND The central governor model putatively explains the mechanism of endurance exercise-induced central fatigue, however high-intensity exercise-induced central fatigue strategies have not been investigated yet. This study aimed to examine how central fatigue affects neural response alterations, as measured by electroencephalographic (EEG) recordings, in intermittent high-intensity cycling. METHODS Neural responses were assessed by measuring the alteration of brainwaves based on spectral energy band estimates during an intermittent, high-intensity, 60-min exercise bout on a cycle ergometer. The cycle ergometer incline was changed every 10 min in an intermittent pattern (10-20-5-20-5-10°). EEG was used to analyze altering brain function. Heart rate (HR), blood lactate (BL), and rating of perceived exertion (RPE) were measured after the participants completed each change in incline. RESULTS The results showed that HR, BL, and RPE increased at an incline of 20° in comparison to a 5° incline. The spectral power of EEG was significantly increased (P ˂ 0.01) in the alpha and beta frequency ranges with a change in inclines between 5 and 20°. The spectral power of the EEG was significantly increased (P ˂ 0.01) over the whole frequency range from rest (theta + 251%, alpha + 165%, beta + 145%). CONCLUSION Higher, relative intensities (10 and 20°) increased brain function, regardless of fatigue occurrence. HIIT (high-intensity interval training) led to an alteration in the neural response. Further work investigating the usefulness of HIIT to improve brain function is warranted.
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Affiliation(s)
- Mehrangiz Ghorbani
- Department of Physical Education and Sport Sciences, Islamic Azad University Bijar Branch, Bijar, Iran.
| | - Cain C T Clark
- Centre for Sport, Exercise and Life Sciences, Coventry University, Coventry, CV1 5FB, UK
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Marshall PW, Finn HT, Enoka RM. Declines in muscle contractility and activation during isometric contractions of the knee extensors vary with contraction intensity and exercise volume. Exp Physiol 2021; 106:2096-2106. [PMID: 34411379 DOI: 10.1113/ep089788] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 08/16/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Is there a critical threshold beyond which the loss of muscle contractility is regulated by the level of muscle activation during single-limb exercise of differing intensities and volumes? What is the main finding and its importance? Plateaus in the decline in muscle contractility during single-limb knee extension depended on both exercise volume and contraction intensity. A plateau was only evident with an increase in exercise volume. Muscle activation increased and did not decline despite substantial reductions in contractility. The findings indicate that the decrease in muscle contractility exhibited by resistance-trained men during the performance of submaximal isometric contractions with the knee extensors was not regulated by the level of muscle activation. ABSTRACT Our study examined the influence of contraction intensity and exercise volume on changes in muscle contractility and activation of the knee extensor muscles. Maximal voluntary torque (MVT) and rate of change in torque, surface electromyograms, voluntary activation, V-waves and quadriceps resting twitch measures were assessed in 10 resistance-trained men during two experimental sessions. Each session began with an initial baseline series of contractions at a fixed intensity of 40% or 80% MVT. The 40%-only session continued with five contractions to task failure at 40% MVT. The 80% session continued with five contractions to failure each at 80%, 60% and 40% MVT. Greater reductions in MVT were observed during the baseline contractions of the 40%-only session compared with the 80% session at each matched-volume time point (P < 0.05), with similar changes in twitch values (P < 0.001). MVT and twitch values plateaued at each intensity during the 80% session and were significantly different across intensities: 80% > 60% > 40% (P < 0.001). There were no differences for measures during the five contractions at 40% MVT performed on the different days, despite a greater volume of exercise performed prior to the 40% MVT during the 80% session. At each contraction intensity, a plateau in contractility loss was observed as more contractions were performed. We found that initial increases in muscle activation were maintained in the presence of increases in exercise volume and, in contrast to the critical-threshold hypothesis, did not decline in parallel with reductions in muscle contractility.
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Affiliation(s)
- Paul W Marshall
- Department of Exercise Sciences, University of Auckland, Auckland, New Zealand.,Human Performance Laboratory, School of Health Sciences, Western Sydney University, Sydney, Australia
| | - Harrison T Finn
- Neuroscience Research Australia (NeuRA), Sydney, Australia.,University of New South Wales, Sydney, Australia
| | - Roger M Enoka
- Department of Integrative Physiology, University of Colorado, Boulder, CO, USA
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Lockyer EJ, Compton CT, Forman DA, Pearcey GE, Button DC, Power KE. Moving forward: methodological considerations for assessing corticospinal excitability during rhythmic motor output in humans. J Neurophysiol 2021; 126:181-194. [PMID: 34133230 DOI: 10.1152/jn.00027.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The use of transcranial magnetic stimulation to assess the excitability of the central nervous system to further understand the neural control of human movement is expansive. The majority of the work performed to-date has assessed corticospinal excitability either at rest or during relatively simple isometric contractions. The results from this work are not easily extrapolated to rhythmic, dynamic motor outputs, given that corticospinal excitability is task-, phase-, intensity-, direction-, and muscle-dependent (Power KE, Lockyer EJ, Forman DA, Button DC. Appl Physiol Nutr Metab 43: 1176-1185, 2018). Assessing corticospinal excitability during rhythmic motor output, however, involves technical challenges that are to be overcome, or at the minimum considered, when attempting to design experiments and interpret the physiological relevance of the results. The purpose of this narrative review is to highlight the research examining corticospinal excitability during a rhythmic motor output and, importantly, to provide recommendations regarding the many factors that must be considered when designing and interpreting findings from studies that involve limb movement. To do so, the majority of work described herein refers to work performed using arm cycling (arm pedaling or arm cranking) as a model of a rhythmic motor output used to examine the neural control of human locomotion.
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Affiliation(s)
- Evan J Lockyer
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Chris T Compton
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Davis A Forman
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Gregory E Pearcey
- Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Department of Physiology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.,Shirley Ryan Ability Lab, Chicago, Illinois
| | - Duane C Button
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
| | - Kevin E Power
- Human Neurophysiology Lab, School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, Newfoundland, Canada.,Faculty of Medicine, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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Laginestra FG, Amann M, Kirmizi E, Giuriato G, Barbi C, Ruzzante F, Pedrinolla A, Martignon C, Tarperi C, Schena F, Venturelli M. Electrically induced quadriceps fatigue in the contralateral leg impairs ipsilateral knee extensors performance. Am J Physiol Regul Integr Comp Physiol 2021; 320:R747-R756. [PMID: 33729017 PMCID: PMC8163605 DOI: 10.1152/ajpregu.00363.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 02/23/2021] [Accepted: 03/12/2021] [Indexed: 11/22/2022]
Abstract
Muscle fatigue induced by voluntary exercise, which requires central motor drive, causes central fatigue that impairs endurance performance of a different, nonfatigued muscle. This study investigated the impact of quadriceps fatigue induced by electrically induced (no central motor drive) contractions on single-leg knee-extension (KE) performance of the subsequently exercising ipsilateral quadriceps. On two separate occasions, eight males completed constant-load (85% of maximal power-output) KE exercise to exhaustion. In a counterbalanced manner, subjects performed the KE exercise with no pre-existing quadriceps fatigue in the contralateral leg on one day (No-PreF), whereas on the other day, the same KE exercise was repeated following electrically induced quadriceps fatigue in the contralateral leg (PreF). Quadriceps fatigue was assessed by evaluating pre- to postexercise changes in potentiated twitch force (ΔQtw,pot; peripheral fatigue), and voluntary muscle activation (ΔVA; central fatigue). As reflected by the 57 ± 11% reduction in electrically evoked pulse force, the electrically induced fatigue protocol caused significant knee-extensors fatigue. KE endurance time to exhaustion was shorter during PreF compared with No-PreF (4.6 ± 1.2 vs 7.7 ± 2.4 min; P < 0.01). Although ΔQtw,pot was significantly larger in No-PreF compared with PreF (-60% vs -52%, P < 0.05), ΔVA was greater in PreF (-14% vs -10%, P < 0.05). Taken together, electrically induced quadriceps fatigue in the contralateral leg limits KE endurance performance and the development of peripheral fatigue in the ipsilateral leg. These findings support the hypothesis that the crossover effect of central fatigue is mainly mediated by group III/IV muscle afferent feedback and suggest that impairments associated with central motor drive may only play a minor role in this phenomenon.
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Affiliation(s)
| | - Markus Amann
- Department of Anaesthesiology, University of Utah, Salt Lake City, Utah
| | - Emine Kirmizi
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
- Department of Physiology, Faculty of Medicine, Uludag University, Eskisehir, Turkey
| | - Gaia Giuriato
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Chiara Barbi
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Federico Ruzzante
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Anna Pedrinolla
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Camilla Martignon
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Cantor Tarperi
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
| | - Federico Schena
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
| | - Massimo Venturelli
- Department of Neurosciences, Biomedicine, and Movement, University of Verona, Verona, Italy
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12
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Sidhu SK. Remote muscle priming anodal transcranial direct current stimulation attenuates short interval intracortical inhibition and increases time to task failure of a constant workload cycling exercise. Exp Brain Res 2021; 239:1975-1985. [PMID: 33891144 DOI: 10.1007/s00221-021-06103-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 03/31/2021] [Indexed: 10/21/2022]
Abstract
Anodal transcranial direct current stimulation (atDCS), a non-invasive neuromodulatory technique has been shown to increase the excitability of targeted brain area and influence endurance exercise performance. However, the effect of atDCS applied on an unexercised muscle motor cortex (M1) representation on GABAA-mediated intracortical inhibition and endurance exercise performance remains unknown. In two separate sessions, twelve subjects performed fatigue cycling exercise (80% peak power output) sustained to task failure in a double-blinded design, following either ten minutes of bicephalic anodal tDCS (atDCS) or sham applied on a non-exercised hand muscle M1 representation. Short interval intracortical inhibition (SICI) was measured at baseline, post neuromodulation and post-exercise using paired-pulse transcranial magnetic stimulation (TMS) in a resting hand muscle. There was a greater decrease in SICI (P < 0.05) post fatigue cycling with atDCS priming compared to sham. Time to task failure (TTF) was significantly increased following atDCS compared to sham (P < 0.05). These findings suggest that atDCS applied over the non-exercised muscle M1 representation can augment cycling exercise performance; and although this outcome may be mediated via a multitude of mechanisms, a decrease in the global excitability of GABAA inhibitory interneurons may be a possible contributing factor.
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Affiliation(s)
- Simranjit K Sidhu
- Discipline of Physiology, Adelaide Medical School, The University of Adelaide, S433, Helen Mayo South, Frome Rd, Adelaide, SA, 5005, Australia.
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13
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Brownstein CG, Millet GY, Thomas K. Neuromuscular responses to fatiguing locomotor exercise. Acta Physiol (Oxf) 2021; 231:e13533. [PMID: 32627930 DOI: 10.1111/apha.13533] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/26/2020] [Accepted: 06/29/2020] [Indexed: 12/26/2022]
Abstract
Over the last two decades, an abundance of research has explored the impact of fatiguing locomotor exercise on the neuromuscular system. Neurostimulation techniques have been implemented prior to and following locomotor exercise tasks of a wide variety of intensities, durations, and modes. These techniques have allowed for the assessment of alterations occurring within the central nervous system and the muscle, while techniques such as transcranial magnetic stimulation and spinal electrical stimulation have permitted further segmentalization of locomotor exercise-induced changes along the motor pathway. To this end, the present review provides a comprehensive synopsis of the literature pertaining to neuromuscular responses to locomotor exercise. Sections of the review were divided to discuss neuromuscular responses to maximal, severe, heavy and moderate intensity, high-intensity intermittent exercise, and differences in neuromuscular responses between exercise modalities. During maximal and severe intensity exercise, alterations in neuromuscular function reside primarily within the muscle. Although post-exercise reductions in voluntary activation following maximal and severe intensity exercise are generally modest, several studies have observed alterations occurring at the cortical and/or spinal level. During prolonged heavy and moderate intensity exercise, impairments in contractile function are attenuated with respect to severe intensity exercise, but are still widely observed. While reductions in voluntary activation are greater during heavy and moderate intensity exercise, the specific alterations occurring within the central nervous system remain unclear. Further work utilizing stimulation techniques during exercise and integrating new and emerging techniques such as high-density electromyography is warranted to provide further insight into neuromuscular responses to locomotor exercise.
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Affiliation(s)
- Callum G. Brownstein
- Inter‐University Laboratory of Human Movement Biology Université LyonUJM‐Saint‐Etienne Saint‐Etienne France
| | - Guillaume Y. Millet
- Inter‐University Laboratory of Human Movement Biology Université LyonUJM‐Saint‐Etienne Saint‐Etienne France
- Institut Universitaire de France (IUF) France
| | - Kevin Thomas
- Faculty of Health and Life Sciences Northumbria University Newcastle upon Tyne United Kingdom
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14
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Ciccone AB, Fry AC, Emerson DM, Gallagher PM, Herda TJ, Weir JP. Effects of Transspinal Direct Current Stimulation on Cycling Perception of Effort and Time to Exhaustion. J Strength Cond Res 2021; 35:347-352. [PMID: 33306592 DOI: 10.1519/jsc.0000000000003876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
ABSTRACT Ciccone, AB, Fry, AC, Emerson, DM, Gallagher, PM, Herda, TJ, and Weir, JP. Effects of transspinal direct current stimulation on cycling perception of effort and time to exhaustion. J Strength Cond Res 35(2): 347-352, 2021-In the past decade, researchers have investigated the efficacy of transspinal direct current stimulation (tsDCS) on the central nervous system and afferent neuron function in humans. Recently, data have suggested it may be possible for such tsDCS-induced changes in neuromuscular function to enhance performance. This study used noninvasive thoracic spine tsDCS to determine if cycling performance and perception of effort could be modulated by tsDCS. In 3 different stimulation conditions, anodal, cathodal, and sham, subjects cycled at 80% of their maximal aerobic capacity until exhaustion and reported their rating of perceived exertion (RPE) every minute. From this period, we compared the RPE responses over the first 3 minutes and time to exhaustion. There was no significant difference in time to exhaustion between anodal (408 ± 121 seconds), cathodal (413 ± 168 seconds), and sham (440 ± 189 seconds) conditions (p = 0.58). There was no significant difference in RPE from minutes 1-3 (collapsed across time) between anodal (12.9 ± 2.4 arbitrary units (AUs)), cathodal (13.3 ± 2.2 AUs), and sham (12.9 ± 2.1 AUs) conditions (p = 0.51). These data suggest tsDCS condition did not influence cycling performance or perception of effort during high-intensity cycling. Therefore, thoracic spine and lower abdominal montage delivering a current density of 0.071 mA·cm-2 for 20 minutes likely does not substantially improve high-intensity cycling work capacity. Therefore, more research is needed to investigate the efficacy of tsDCS and which stimulation methods may and may not enhance human performance.
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Affiliation(s)
- Anthony B Ciccone
- Department of Exercise Science and Outdoor Recreation, Utah Valley University, Orem, Utah; and
| | - Andrew C Fry
- Osness Human Performance Laboratories, Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
| | - Dawn M Emerson
- Osness Human Performance Laboratories, Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
| | - Philip M Gallagher
- Osness Human Performance Laboratories, Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
| | - Trent J Herda
- Osness Human Performance Laboratories, Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
| | - Joseph P Weir
- Osness Human Performance Laboratories, Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence, Kansas
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15
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Shyamali Kaushalya F, Romero-Arenas S, García-Ramos A, Colomer-Poveda D, Marquez G. Acute effects of transcranial direct current stimulation on cycling and running performance. A systematic review and meta-analysis. Eur J Sport Sci 2021; 22:113-125. [PMID: 33280514 DOI: 10.1080/17461391.2020.1856933] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Transcranial direct current stimulation (tDCS) has been proven to induce positive effects on athletic performance. The present study aimed to analyse the effect of anodal-tDCS on endurance (time to exhaustion [TTE] or endurance time trial [ETT]) and sprint performance during cycling and running tasks. We performed a systematic literature review in the databases Medline (via PubMed), SPORTDiscus and Science Direct. We included only randomised controlled trials conducted with healthy individuals in which an anodal-tDCS protocol was applied prior to cycling or running tests. The effect of anodal-tDCS (experimental condition) was compared against sham stimulation (control condition). A total of 15 interventions from 13 studies were included. The sub-group analysis revealed a positive effect of anodal-tDCS on TTE (standardised mean differences [SMD] = 0.37; 90% confidence interval [CI] = 0.13, 0.61; p = 0.01), but not on ETT (SMD = 0.00; 90% CI = -0.29, 0.30; p = 1.00) or sprint performance (SMD = 0.19; 90% CI = -0.23, 0.60; p = 0.46). The current meta-analysis suggests that the effect of anodal-tDCS on whole-body dynamic exercises (running and cycling) could be task dependent. Specifically, anodal-tDCS enhance running and cycling time to exhaustion performance during TTE tasks but not ETT or sprint tasks. The increase in cortical excitability induced by anodal-tDCS may lead to lower ratings of perceived exertion by reducing the input required to perform the physical task. Task should be taken into account, because it is probably influencing the result obtained by anodal-tDCS.
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Affiliation(s)
- Fernando Shyamali Kaushalya
- Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain
| | - Salvador Romero-Arenas
- Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain
| | - Amador García-Ramos
- Department of Sports Sciences and Physical Conditioning, Faculty of Education, Universidad Catolica de la Santisima Concepcion, Concepción, Chile.,Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain
| | | | - Gonzalo Marquez
- Department of Physical Education and Sport, Faculty of Sport Sciences, Catholic University of Murcia (UCAM), Murcia, Spain.,Department of Physical Education, Faculty of Sciences of Sport and Physical Education, University of A Coruña, A Coruña, Spain
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16
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Hureau TJ, Weavil JC, Sidhu SK, Thurston TS, Reese VR, Zhao J, Nelson AD, Birgenheier NM, Richardson RS, Amann M. Ascorbate attenuates cycling exercise-induced neuromuscular fatigue but fails to improve exertional dyspnea and exercise tolerance in COPD. J Appl Physiol (1985) 2021; 130:69-79. [PMID: 33151775 PMCID: PMC7944926 DOI: 10.1152/japplphysiol.00611.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 11/22/2022] Open
Abstract
We examined the effect of intravenous ascorbate (VitC) administration on exercise-induced redox balance, inflammation, exertional dyspnea, neuromuscular fatigue, and exercise tolerance in patients with chronic obstructive pulmonary disease (COPD). Eight COPD patients completed constant-load cycling (∼80% of peak power output, 83 ± 10 W) to task failure after intravenous VitC (2 g) or saline (placebo, PL) infusion. All participants repeated the shorter of the two exercise trials (isotime) with the other infusate. Quadriceps fatigue was determined by pre- to postexercise changes in quadriceps twitch torque (ΔQtw, electrical femoral nerve stimulation). Corticospinal excitability before, during, and after exercise was assessed by changes in motor evoked potentials triggered by transcranial magnetic stimulation. VitC increased superoxide dismutase (marker for endogenous antioxidant capacity) by 129% and mitigated C-reactive protein (marker for inflammation) in the plasma during exercise but failed to alter the exercise-induced increase in lipid peroxidation (malondialdehyde) and free radicals [electron paramagnetic resonance (EPR)-spectroscopy]. Although VitC did, indeed, decrease neuromuscular fatigue (ΔQtw: PL -29 ± 5%, VitC -23 ± 6%, P < 0.05), there was no impact on corticospinal excitability and time to task failure (∼8 min, P = 0.8). Interestingly, in terms of pulmonary limitations to exercise, VitC had no effect on perceived exertional dyspnea (∼8.5/10) and its determinants, including oxygen saturation ([Formula: see text]) (∼92%) and respiratory muscle work (∼650 cmH2O·s·min-1) (P > 0.3). Thus, although VitC facilitated indicators for antioxidant capacity, diminished inflammatory markers, and improved neuromuscular fatigue resistance, it failed to improve exertional dyspnea and cycling exercise tolerance in patients with COPD. As dyspnea is recognized to limit exercise tolerance in COPD, the otherwise beneficial effects of VitC may have been impacted by this unaltered sensation.NEW & NOTEWORTHY We investigated the effect of intravenous vitamin C on redox balance, exertional dyspnea, neuromuscular fatigue, and exercise tolerance in chronic obstructive pulmonary disease (COPD) patients. Acute vitamin C administration increased superoxide dismutase (marker of antioxidant capacity) and attenuated fatigue development but failed to improve exertional dyspnea and exercise tolerance. These findings suggest that a compromised redox balance plays a critical role in the development of fatigue in COPD but also highlight the significance of exertional dyspnea as an important symptom limiting the patients' exercise tolerance.
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Affiliation(s)
- Thomas J Hureau
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
- EA 3072 Mitochondria, Oxidative Stress and Muscular Protection Laboratory, Department of Medicine, University of Strasbourg, Strasbourg, France
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah
| | - Simranjit K Sidhu
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Van R Reese
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Jia Zhao
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | - Ashley D Nelson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
| | | | - Russell S Richardson
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
| | - Markus Amann
- Department of Internal Medicine, University of Utah, Salt Lake City, Utah
- Geriatric Research, Education, and Clinical Center, Salt Lake City Department of Veterans Affairs Medical Center, Salt Lake City, Utah
- Department of Anesthesiology, University of Utah, Salt Lake City, Utah
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, Utah
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17
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Amann M, Wan HY, Thurston TS, Georgescu VP, Weavil JC. On the Influence of Group III/IV Muscle Afferent Feedback on Endurance Exercise Performance. Exerc Sport Sci Rev 2020; 48:209-216. [PMID: 32658041 DOI: 10.1249/jes.0000000000000233] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This review discusses evidence suggesting that group III/IV muscle afferents affect locomotor performance by influencing neuromuscular fatigue. These neurons regulate the hemodynamic and ventilatory response to exercise and, thus, assure appropriate locomotor muscle O2 delivery, which optimizes peripheral fatigue development and facilitates endurance performance. In terms of central fatigue, group III/IV muscle afferents inhibit motoneuronal output and thereby limit exercise performance.
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Affiliation(s)
| | - Hsuan-Yu Wan
- Department of Anesthesiology, University of Utah
| | - Taylor S Thurston
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
| | - Vincent P Georgescu
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT
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18
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Ansdell P, Thomas K, Hicks KM, Hunter SK, Howatson G, Goodall S. Physiological sex differences affect the integrative response to exercise: acute and chronic implications. Exp Physiol 2020; 105:2007-2021. [PMID: 33002256 DOI: 10.1113/ep088548] [Citation(s) in RCA: 143] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the topic of this review? We review sex differences within physiological systems implicated in exercise performance; specifically, how they integrate to determine metabolic thresholds and fatigability. Thereafter, we discuss the implications that these sex differences might have for long-term adaptation to exercise. What advances does it highlight? The review collates evidence from recent physiological studies that have investigated sex as a biological variable, demonstrating that the physiological response to equivalent 'dosages' of exercise is not the same in males and females; thus, highlighting the need to research diversity in physiological responses to interventions. ABSTRACT The anatomical and physiological differences between males and females are thought to determine differences in the limits of human performance. The notion of studying sex as a biological variable has recently been emphasized in the biosciences as a vital step in enhancing human health. In this review, we contend that the effects of biological sex on acute and chronic responses must be studied and accounted for when prescribing aerobic exercise, much like any intervention targeting the optimization of physiological function. Emerging evidence suggests that the response of physiological systems to exercise differs between males and females, potentially mediating the beneficial effects in healthy and clinical populations. We highlight evidence that integrative metabolic thresholds during exercise are influenced by phenotypical sex differences throughout many physiological systems. Furthermore, we discuss evidence that female skeletal muscle is more resistant to fatigue elicited by equivalent dosages of high-intensity exercise. How the different acute responses affect the long-term trainability of males and females is considered, with discussion about tailoring exercise to the characteristics of the individual presented within the context of biological sex. Finally, we highlight the influence of endogenous and exogenous sex hormones on physiological responses to exercise in females. Sex is one of many mediating influences on the outcomes of exercise, and with careful experimental designs, physiologists can advance the collective understanding of diversity in physiology and optimize outcomes for both sexes.
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Affiliation(s)
- Paul Ansdell
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Kevin Thomas
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Kirsty M Hicks
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.,Water Research Group, School of Environmental Sciences and Development, North-West University, Potchefstroom, South Africa
| | - Stuart Goodall
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
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19
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Ansdell P, Škarabot J, Atkinson E, Corden S, Tygart A, Hicks KM, Thomas K, Hunter SK, Howatson G, Goodall S. Sex differences in fatigability following exercise normalised to the power-duration relationship. J Physiol 2020; 598:5717-5737. [PMID: 32964441 DOI: 10.1113/jp280031] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/07/2020] [Indexed: 01/24/2023] Open
Abstract
KEY POINTS Knee-extensors demonstrate greater fatigue resistance in females compared to males during single-limb and whole-body exercise. For single-limb exercise, the intensity-duration relationship is different between sexes, with females sustaining a greater relative intensity of exercise. This study established the power-duration relationship during cycling, then assessed fatigability during critical power-matched exercise within the heavy and severe intensity domains. When critical power and the curvature constant were expressed relative to maximal ramp test power, no sex difference was observed. No sex difference in time to task failure was observed in either trial. During heavy and severe intensity cycling, females experienced lesser muscle de-oxygenation. Following both trials, females experienced lesser reductions in knee-extensor contractile function, and following heavy intensity exercise, females experienced less reduction in voluntary activation. These data demonstrate that whilst the relative power-duration relationship is not different between males and females, the mechanisms of fatigability during critical power-matched exercise are mediated by sex. ABSTRACT Due to morphological differences, females demonstrate greater fatigue resistance of locomotor muscle during single-limb and whole-body exercise modalities. Whilst females sustain a greater relative intensity of single-limb, isometric exercise than males, limited investigation has been performed during whole-body exercise. Accordingly, this study established the power-duration relationship during cycling in 18 trained participants (eight females). Subsequently, constant-load exercise was performed at critical power (CP)-matched intensities within the heavy and severe domains, with the mechanisms of fatigability assessed via non-invasive neurostimulation, near-infrared spectroscopy and pulmonary gas exchange during and following exercise. Relative CP (72 ± 5 vs. 74 ± 2% Pmax , P = 0.210) and curvature constant (51 ± 11 vs. 52 ± 10 J Pmax -1 , P = 0.733) of the power-duration relationship were similar between males and females. Subsequent heavy (P = 0.758) and severe intensity (P = 0.645) exercise time to task failures were not different between sexes. However, females experienced lesser reductions in contractile function at task failure (P ≤ 0.020), and greater vastus lateralis oxygenation (P ≤ 0.039) during both trials. Reductions in voluntary activation occurred following both trials (P < 0.001), but were less in females following the heavy trial (P = 0.036). Furthermore, during the heavy intensity trial only, corticospinal excitability was reduced at the cortical (P = 0.020) and spinal (P = 0.036) levels, but these reductions were not sex-dependent. Other than a lower respiratory exchange ratio in the heavy trial for females (P = 0.039), no gas exchange variables differed between sexes (P ≥ 0.052). Collectively, these data demonstrate that whilst the relative power-duration relationship is not different between males and females, the mechanisms of fatigability during CP-matched exercise above and below CP are mediated by sex.
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Affiliation(s)
- Paul Ansdell
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Jakob Škarabot
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Elliott Atkinson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Sarah Corden
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Amber Tygart
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Kirsty M Hicks
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Kevin Thomas
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK.,Water Research Group, School of Environmental Sciences and Development, North-West University, Potchefstroom, South Africa
| | - Stuart Goodall
- Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, UK
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20
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Coates KD, Aboodarda SJ, Krüger RL, Martin T, Metz LM, Jarvis SE, Millet GY. Multiple sclerosis-related fatigue: the role of impaired corticospinal responses and heightened exercise fatigability. J Neurophysiol 2020; 124:1131-1143. [PMID: 32877296 DOI: 10.1152/jn.00165.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
It is unclear whether motor fatigability and perceived fatigue share a common pathophysiology in people with multiple sclerosis (PwMS). This cross-sectional investigation explored the relationship between the mechanisms of motor fatigability from cycling and fatigue severity in PwMS. Thirteen highly fatigued (HF) and thirteen nonfatigued (LF) PwMS and thirteen healthy controls (CON) completed a step test until volitional exhaustion on an innovative cycle ergometer. Neuromuscular evaluations involving femoral nerve electrical stimulation and transcranial magnetic stimulation were performed every 3 min throughout cycling. One-way ANOVA at baseline and exhaustion uncovered evidence of consistently smaller motor evoked potential (MEP) amplitudes (P = 0.011) and prolonged MEP latencies (P = 0.041) in HF as well as a greater decline in maximal voluntary contraction force (HF: 63 ± 13%; LF: 75 ± 13%; CON: 73 ± 11% of pre; P = 0.037) and potentiated twitch force (HF: 35 ± 13%; LF: 50 ± 16%; CON: 47 ± 17% of pre; P = 0.049) in HF at volitional exhaustion. Hierarchical regression determined that fatigue severity on the Fatigue Severity Scale was predicted by prolonged MEP latencies (change in r2 = 0.389), elevated peripheral muscle fatigability (change in r2 = 0.183), and depressive symptoms (change in r2 = 0.213). These findings indicate that MS-related fatigue is distinguished by disrupted corticospinal responsiveness, which could suggest progressive pathology, but fatigability from whole body exercise and depressive symptoms also influence perceptions of fatigue in PwMS.NEW & NOTEWORTHY The etiology of fatigability from whole body exercise was examined for the first time to accurately elucidate the relationship between fatigue and fatigability in multiple sclerosis (MS). Compromised corticospinal responsiveness predicted fatigue severity, providing a novel, objective indicator of fatigue in MS. Although the impaired corticomotor transmission did not aggravate muscle activation in this group of people with multiple sclerosis (PwMS) of lower disability, heightened muscle fatigability was seen to contribute to perceptions of fatigue in PwMS.
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Affiliation(s)
- Kyla D Coates
- Neuromuscular Fatigue Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Saied Jalal Aboodarda
- Neuromuscular Fatigue Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Renata L Krüger
- Neuromuscular Fatigue Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada
| | - Tristan Martin
- Neuromuscular Fatigue Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Unité Mixte de Recherche-S 1075 Comete Moblites: Vieillissement Pathologies Santé, Institut National de la Santé et de la Recherche Médicale, Normandy University, Caen, France
| | - Luanne M Metz
- Hotchkiss Brain Institute and the Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Scott E Jarvis
- Hotchkiss Brain Institute and the Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Guillaume Y Millet
- Neuromuscular Fatigue Laboratory, Faculty of Kinesiology, University of Calgary, Calgary, Alberta, Canada.,Inter-University Laboratory of Human Movement Biology, Jean Monnet University-Saint-Etienne, University of Lyon, Saint-Etienne, France.,Institut Universitaire de France, Paris, France
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21
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Ghorbani M, Ghazalian F, Ebrahim K, Abednatanzi H. Altered Neural Response Induced by Central-Fatigue in the Cortical Area During High-Intensity Interval Pedaling. Basic Clin Neurosci 2020; 10:631-639. [PMID: 32477480 PMCID: PMC7253810 DOI: 10.32598/bcn.9.10.440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 01/10/2019] [Accepted: 06/30/2019] [Indexed: 11/20/2022] Open
Abstract
Introduction The central-governor model explains the mechanism of endurance exercise-induced central fatigue, but high-intensity exercise-induced central fatigue has not been investigated yet. This study aimed to research how central fatigue during high-intensity intermittent pedaling alters the neural response, which results in Electroencephalography (EEG) recordings. Methods We assessed neural response by measuring the alternation of brainwave spectral power during an intermittent high-intensity 60-minute exercise on an ergometer cycle. The cadences were changed every 10 minutes according to intermittent pattern altering (90-120-60-120-60-90 rpm). EEG was used to analyze altering brain function. Heart Rate (HR), Blood Lactate (BL), and Rating of Perceived Exertion (RPE) were measured after the change in cadences. Results HR, BL, and RPE increased at a cadence of 120 rpm compared with 60 rpm on the ergometer cycle. The spectral power of EEG, according to cadence × brainwaves, significantly increased (P<0.01) in the alpha and beta frequency ranges with a change in cadences between 60 rpm and 120 rpm. The spectral power of the EEG significantly increased (P<0.01) over the whole frequency range from rest to warming (theta: 251%, alpha: 165%, beta: 145%) and significantly reduced in theta, alpha, and beta (theta: 176%, alpha: 142%, beta: 77%) (P≤0.01). Conclusion High-intensity exercises (90 and 120 cadences) increased brain function, regardless of fatigue occurrence. High-intensity interval training (HIIT) led to altering the neural response. It would be required to investigate the usefulness of HIIT to treat some of the psychotic disorders.
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Affiliation(s)
- Mehrangiz Ghorbani
- Department of Physical Education and Sport Sciences, Faculty of Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.,Department of Physical Education and Sport Sciences, Bijar Branch, Islamic Azad University, Bijar, Iran
| | - Farshad Ghazalian
- Department of Physical Education and Sport Sciences, Faculty of Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Khosrow Ebrahim
- Department of Physical Education and Sport Sciences, Faculty of Humanities, Shahid Beheshti University, Tehran, Iran
| | - Hossein Abednatanzi
- Department of Physical Education and Sport Sciences, Faculty of Humanities and Social Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran
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22
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Clos P, Garnier Y, Martin A, Lepers R. Corticospinal excitability is altered similarly following concentric and eccentric maximal contractions. Eur J Appl Physiol 2020; 120:1457-1469. [PMID: 32347373 DOI: 10.1007/s00421-020-04377-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Accepted: 04/13/2020] [Indexed: 01/24/2023]
Abstract
PURPOSE To examine corticospinal excitability and neuromuscular function following the completion of eccentric (ECC) or concentric (CON) maximal exercises of same mechanical work. METHODS Ten males (29.9 ± 11.8 years) performed maximal isokinetic knee extensor contractions in four experimental sessions. The two first sessions (one in ECC and one in CON) ended with a dynamic peak torque loss of 20%. The work completed in each contraction type was then achieved in the other contraction type. Neuromuscular function- maximal voluntary isometric contraction (MVIC), voluntary activation level (VAL), potentiated doublet (Dt), M-wave- and corticospinal excitability- motor evoked potential (MEP) amplitude and silent period (SP)-were assessed in the vastus lateralis (VL) and rectus femoris (RF) muscles at 20% MVIC before and immediately after exercise. RESULTS To lose 20% of dynamic peak torque subjects performed 1.8 times more work in ECC than CON (P = 0.03), inducing a non-different decline in MVIC (P = 0.15). VAL dropped after the ECC sessions only (- 8.5 ± 6.7%; all P < 0.027). Only, the CON session featuring the greatest work affected Dt amplitude (- 9.4 ± 23.8%; P = 0.047). In both muscles, MEP amplitude decreased (all P < 0.001) and MEP SP stayed constant (all P > 0.45), irrespective of contraction type (all P > 0.15). CONCLUSION Same-work maximal ECC and CON exercises induced similar fatigue level but from different origins (preferentially central for ECC vs peripheral for CON). Yet, net corticospinal excitability did not depend on contraction type.
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Affiliation(s)
- Pierre Clos
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, 21000, Dijon, France.
| | - Yoann Garnier
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, 21000, Dijon, France
- Clermont-Auvergne University, AME2P, Clermont-Ferrand, France
| | - Alain Martin
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, 21000, Dijon, France
| | - Romuald Lepers
- INSERM UMR1093-CAPS, Université Bourgogne Franche-Comté, UFR des Sciences du Sport, 21000, Dijon, France
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Changes in the quadriceps spinal reflex pathway after repeated sprint cycling are not influenced by ischemic preconditioning. Eur J Appl Physiol 2020; 120:1189-1202. [PMID: 32239310 DOI: 10.1007/s00421-020-04359-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Accepted: 03/24/2020] [Indexed: 12/11/2022]
Abstract
PURPOSE We examined the effect of ischemic preconditioning (IPC) on changes in muscle force, activation, and the spinal reflex pathway during and after repeated sprint cycling. METHODS Eight recreationally active men (high-intensity cardiorespiratory training > 3 times per week, > 6 months) completed two exercise sessions (5 sets of 5 cycling sprints, 150% max W), preceded by either IPC (3 × 5 min leg occlusions at 220 mmHg) or SHAM (3 × 5 min at 20 mmHg). Knee extensor maximal force and rate of force were measured before (PRE), immediately post (POST), 1H, and 24H after cycling. Twitch interpolation and resting potentiated twitches were applied to estimate voluntary activation and muscle contractility, respectively. Quadriceps H-reflex recruitment curves were collected at all time-points using 10 Hz doublet stimulation to allow estimation of H-reflex post-activation depression. Surface electromyograms and tissue oxygenation (via near-infrared spectroscopy) were continuously recorded during cycling. RESULTS IPC did not affect any measure of neuromuscular function or performance during cycling. Maximal force and muscle contractility were significantly lower at POST and 1H compared to PRE and 24H by up to 50% (p < 0.01). Maximal force was lower than PRE at 24H by 8.7% (p = 0.028). Voluntary activation and rate of force were unchanged. A rightwards shift was observed for the H-reflex recruitment curve POST, and post-activation depression was higher than all other time-points at 24H (p < 0.05). Muscle activation and oxygenation decreased during cycling. CONCLUSIONS IPC has a nominal effect on mechanisms associated with neuromuscular function during and after exercise in healthy populations.
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Sasada S, Endoh T, Ishii T, Kawashima K, Sato S, Hayashi A, Komiyama T. Differential effects of transcranial direct current stimulation on sprint and endurance cycling. TRANSLATIONAL SPORTS MEDICINE 2020. [DOI: 10.1002/tsm2.129] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Syusaku Sasada
- Department of Food and Nutrition Science Sagami Women's University Kanagawa Japan
| | - Takashi Endoh
- Faculty of Development and Education Uekusa Gakuen University Chiba Japan
| | - Tomoya Ishii
- Division of Health and Sport Education United of Graduate School of Education Tokyo Gakugei University Tokyo Japan
| | | | - Shuta Sato
- Graduate School of Education Chiba University Chiba Japan
| | | | - Tomoyoshi Komiyama
- Division of Health and Sport Education United of Graduate School of Education Tokyo Gakugei University Tokyo Japan
- Graduate School of Education Chiba University Chiba Japan
- Faculty of Education Chiba University Chiba Japan
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25
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Brownstein CG, Souron R, Royer N, Singh B, Lapole T, Millet GY. Disparate kinetics of change in responses to electrical stimulation at the thoracic and lumbar level during fatiguing isometric knee extension. J Appl Physiol (1985) 2020; 128:159-167. [DOI: 10.1152/japplphysiol.00635.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The present study compared the fatigue-induced change of matched-amplitude thoracic evoked potential (TMEP) and lumbar evoked potential (LEP) following electrical stimulation. Ten participants performed a 3 × 3 min isometric knee extension contraction separated by 4 min of recovery at the level of EMG required to produce 50% maximal voluntary contraction (MVC) force at baseline. The TMEP and LEP were evoked during the ongoing contraction at baseline and every minute into the fatiguing protocol and during recovery. Both responses were also assessed during a transcranial magnetic stimulation (TMS) evoked silent period to elicit a TMS-TMEP and TMS-LEP to assess responses without the confounding influence of descending drive. The results displayed disparate kinetics of the TMS-TMEP and TMS-LEP throughout the fatiguing protocol. The TMS-TMEP was reduced at all time points during exercise ( P < 0.001), whereas the TMS-LEP was reduced at 2 min into set 1 and 1 min into sets 2 and 3 ( P ≤ 0.04). TMS-LEPs were higher than the TMS-TMEPs at most time points ( P ≤ 0.04). No change was observed in the TMEP or LEP. When evoked during the silent period, the reduction in TMEP is greater than the LEP during fatiguing isometric exercise. The disparate kinetics of change suggest that differential mechanisms are responsible for evoked responses to thoracic and lumbar stimulation. More research is required to identify the mechanisms responsible for the TMEP and LEP before precise inferences can be made on what fatigue-induced changes in these variables reflect. NEW & NOTEWORTHY Assessing spinal excitability using lumbar stimulation when measuring responses in lower limbs has been suggested as an alternative method that could circumvent the issues associated with thoracic stimulation. The present study compared responses to the two types of stimuli throughout a fatiguing protocol and demonstrated that lumbar evoked responses differ substantially from thoracic responses when measured in the absence of voluntary drive. These findings suggest that different mechanisms are responsible for evoked responses to thoracic and lumbar stimuli.
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Affiliation(s)
- Callum G. Brownstein
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
| | - Robin Souron
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
| | - Nicolas Royer
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
| | - Benjamin Singh
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
| | - Thomas Lapole
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
| | - Guillaume Y. Millet
- Inter-university Laboratory of Human Movement Biology, University of Lyon, Jean Monnet University, Saint-Etienne, France
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26
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Ansdell P, Brownstein CG, Škarabot J, Hicks KM, Howatson G, Thomas K, Hunter SK, Goodall S. Sex differences in fatigability and recovery relative to the intensity-duration relationship. J Physiol 2019; 597:5577-5595. [PMID: 31529693 DOI: 10.1113/jp278699] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 09/12/2019] [Indexed: 12/15/2022] Open
Abstract
KEY POINTS Females demonstrate greater fatigue resistance than males during contractions at intensities relative to maximum force. However, previous studies have not accounted for the influence of metabolic thresholds on fatigability. This study is the first to test whether sex differences in fatigability exist when exercise intensity is normalised relative to a metabolic threshold: the critical intensity derived from assessment of the intensity-duration relationship during intermittent, isometric knee extensor contractions. We show that critical intensity in females occurred at a higher percentage of maximum force compared to males. Furthermore, females demonstrated greater fatigue resistance at exercise intensities above and below this metabolic threshold. Our data suggest that the sex difference was mediated by lesser deoxygenation of the knee extensors during exercise. These data highlight the importance of accounting for metabolic thresholds when comparing fatigability between sexes, whilst emphasising the notion that male data are not generalisable to female populations. ABSTRACT Females are less fatigable than males during isometric exercise at intensities relative to maximal voluntary contraction (MVC); however, whether a sex difference in fatigability exists when exercise is prescribed relative to a critical intensity is unknown. This study established the intensity-duration relationship, and compared fatigability and recovery between sexes following intermittent isometric contractions normalised to critical intensity. Twenty participants (10 females) completed four intermittent isometric knee extension trials to task failure to determine critical intensity and the curvature constant (W'), followed by fatiguing tasks at +10% and -10% relative to critical intensity. Neuromuscular assessments were completed at baseline and for 45 min post-exercise. Non-invasive neurostimulation, near-infrared spectroscopy, and non-invasive haemodynamic monitoring were used to elucidate the physiological mechanisms responsible for sex differences. Females demonstrated a greater critical intensity relative to MVC than males (25 ± 3 vs. 21 ± 2% MVC, P = 0.003), with no sex difference for W' (18,206 ± 6331 vs. 18,756 ± 5762 N s, P = 0.850). Time to task failure was greater for females (62.37 ± 17.25 vs. 30.43 ± 12.75 min, P < 0.001) during the +10% trial, and contractile function recovered faster post-exercise (P = 0.034). During the -10% trial females experienced less contractile dysfunction (P = 0.011). Throughout the +10% trial, females demonstrated lesser decreases in deoxyhaemoglobin (P = 0.007) and an attenuated exercise pressor reflex. These data show that a sex difference in fatigability exists even when exercise is matched for critical intensity. We propose that greater oxygen availability during exercise permits females to sustain a higher relative intensity than males, and is an explanatory factor for the sex difference in fatigability during intermittent, isometric contractions.
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Affiliation(s)
- Paul Ansdell
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK
| | - Callum G Brownstein
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK.,Université Lyon, UJM-Saint-Etienne, Inter-university Laboratory of Human Movement Biology, Saint-Etienne, France
| | - Jakob Škarabot
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK
| | - Kirsty M Hicks
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK
| | - Glyn Howatson
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK.,Water Research Group, School of Environmental Sciences and Development, Northwest University, Potchefstroom, South Africa
| | - Kevin Thomas
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK
| | - Sandra K Hunter
- Department of Physical Therapy, Marquette University, Milwaukee, WI, USA
| | - Stuart Goodall
- Faculty of Health and Life Sciences, Northumbria University, Newcastle Upon Tyne, UK
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27
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Weavil JC, Amann M. Corticospinal excitability during fatiguing whole body exercise. PROGRESS IN BRAIN RESEARCH 2018; 240:219-246. [PMID: 30390833 PMCID: PMC6363483 DOI: 10.1016/bs.pbr.2018.07.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The corticospinal pathway is considered the primary conduit for voluntary motor control in humans. The efficacy of the corticospinal pathway to relay neural signals from higher brain areas to the locomotor muscle, i.e., corticospinal excitability, is subject to alterations during exercise. While the integrity of this motor pathway has historically been examined during single-joint contractions, a small number of investigations have recently focused on whole body exercise, such as cycling or rowing. Although differences in methodologies employed between these studies complicate the interpretation of the existing literature, it appears that the net excitability of the corticospinal pathway remains unaltered during fatiguing whole body exercise. Importantly, this lack of an apparent effect does not designate the absence of change, but a counterbalance of excitatory and inhibitory influences on the two components of the corticospinal pathway, namely the motor cortex and the spinal motoneurons. Specific emphasis is put on group III/IV afferent feedback from locomotor muscle which has been suggested to play a significant role in mediating these changes. Overall, this review aims at summarizing our limited understanding of how fatiguing whole body exercise influences the corticospinal pathway.
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Affiliation(s)
- Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT, United States; Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States.
| | - Markus Amann
- Geriatric Research, Education, and Clinical Center, Salt Lake City VAMC, Salt Lake City, UT, United States; Department of Internal Medicine, University of Utah, Salt Lake City, UT, United States; Department of Anesthesiology, University of Utah, Salt Lake City, UT, United States
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28
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Sidhu SK, Weavil JC, Thurston TS, Rosenberger D, Jessop JE, Wang E, Richardson RS, McNeil CJ, Amann M. Fatigue-related group III/IV muscle afferent feedback facilitates intracortical inhibition during locomotor exercise. J Physiol 2018; 596:4789-4801. [PMID: 30095164 DOI: 10.1113/jp276460] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 07/25/2018] [Indexed: 01/22/2023] Open
Abstract
KEY POINTS This study investigated the influence of group III/IV muscle afferents on corticospinal excitability during cycling exercise and focused on GABAB neuron-mediated inhibition as a potential underlying mechanism. The study provides novel evidence to demonstrate that group III/IV muscle afferent feedback facilitates inhibitory intracortical neurons during whole body exercise. Firing of these interneurons probably contributes to the development of central fatigue during physical activity. ABSTRACT We investigated the influence of group III/IV muscle afferents in determining corticospinal excitability during cycling exercise and focused on GABAB neuron-mediated inhibition as a potential underlying mechanism. Both under control conditions (CTRL) and with lumbar intrathecal fentanyl (FENT) impairing feedback from group III/IV leg muscle afferents, subjects (n = 11) cycled at a comparable vastus-lateralis EMG signal (∼0.26 mV) before (PRE; 100 W) and immediately after (POST; 90 ± 2 W) fatiguing constant-load cycling exercise (80% Wpeak; 221 ± 10 W; ∼8 min). During, PRE and POST cycling, single and paired-pulse (100 ms interstimulus interval) transcranial magnetic stimulations (TMS) were applied to elicit unconditioned and conditioned motor-evoked potentials (MEPs), respectively. To distinguish between cortical and spinal contributions to the MEPs, cervicomedullary stimulations (CMS) were used to elicit unconditioned (CMS only) and conditioned (TMS+CMS, 100 ms interval) cervicomedullary motor-evoked potentials (CMEPs). While unconditioned MEPs were unchanged from PRE to POST in CTRL, unconditioned CMEPs increased significantly, resulting in a decrease in unconditioned MEP/CMEP (P < 0.05). This paralleled a reduction in conditioned MEP (P < 0.05) and no change in conditioned CMEP. During FENT, unconditioned and conditioned MEPs and CMEPs were similar and comparable during PRE and POST (P > 0.2). These findings reveal that feedback from group III/IV muscle afferents innervating locomotor muscle decreases the excitability of the motor cortex during fatiguing cycling exercise. This impairment is, at least in part, determined by the facilitating effect of these sensory neurons on inhibitory GABAB intracortical interneurons.
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Affiliation(s)
- Simranjit K Sidhu
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Adelaide Medical School, Discipline of Physiology, The University of Adelaide, Australia
| | - Joshua C Weavil
- Geriatric Research, Education, and Clinical Center, VAMC, Salt Lake City, UT, USA
| | - Taylor S Thurston
- Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | | | - Jacob E Jessop
- Department of Anesthesiology, University of Utah, Salt Lake City, UT, USA
| | - Eivind Wang
- Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - Russell S Richardson
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, VAMC, Salt Lake City, UT, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA
| | - Chris J McNeil
- Centre for Heart, Lung and Vascular Health, School of Health and Exercise Sciences, University of British Columbia, Kelowna, British Columbia, Canada
| | - Markus Amann
- Department of Internal Medicine, University of Utah, Salt Lake City, UT, USA.,Geriatric Research, Education, and Clinical Center, VAMC, Salt Lake City, UT, USA.,Department of Nutrition and Integrative Physiology, University of Utah, Salt Lake City, UT, USA.,Department of Anesthesiology, University of Utah, Salt Lake City, UT, USA
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29
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Aboodarda SJ, Mira J, Floreani M, Jaswal R, Moon SJ, Amery K, Rupp T, Millet GY. Effects of endurance cycling training on neuromuscular fatigue in healthy active men. Part II: Corticospinal excitability and voluntary activation. Eur J Appl Physiol 2018; 118:2295-2305. [DOI: 10.1007/s00421-018-3951-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/23/2018] [Indexed: 10/28/2022]
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30
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Coratella G, Grosprêtre S, Gimenez P, Mourot L. Greater fatigability in knee-flexors vs. knee-extensors after a standardized fatiguing protocol. Eur J Sport Sci 2018; 18:1110-1118. [PMID: 29738677 DOI: 10.1080/17461391.2018.1469674] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The present study aimed to investigate the effects of a standardized fatiguing protocol on central and peripheral fatigue in knee-flexors and knee-extensors. Thirteen healthy men (age: 23 ± 3 years; height: 1.78 ± 0.09 m; body-mass: 73.6 ± 9.2 kg) volunteered for the present study. Maximal voluntary contraction (MVC), Electromyography (EMG) activity, voluntary activation level (VAL) as an index of central fatigue and twitch potentiation as an index of peripheral fatigue were measured before and after the fatiguing protocol. The fatiguing protocol consisted of a 0.6 duty-cycle to exhaustion (6 s isometric contraction, 4 s recovery) at 70% MVC. After the fatiguing protocol, MVC decreased in both (Effect-size (ES) = 1.14) and knee-extensors (ES = 1.14), and EMG activity increased in both knee-flexors (ES = 2.33) and knee-extensors (ES = 1.54). Decreases in VAL occurred in knee-flexors (ES = 0.92) but not in knee-extensors (ES = 0.04). Decreases in potentiation occurred in both knee-flexors (ES = 0.84) and knee-extensors (ES = 0.58). The greater central occurrence of fatigue in knee-flexors than in knee-extensors may depend on the different muscle morphology and coupled with a greater tolerance to fatigue in knee-extensors. The present data add further insight to the complicated knee-flexors-to-knee-extensors strength relationship and the mechanisms behind the different occurrence of fatigue.
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Affiliation(s)
- Giuseppe Coratella
- a EA4660-C3S Laboratory - Culture, Sports, Health and Society and Exercise Performance, Health, Innovation Platform , Univ. Bourgogne Franche-Comté , Besançon , France.,b Department of Biomedical Sciences for Health , University of Milan , Milan , Italy
| | - Sidney Grosprêtre
- a EA4660-C3S Laboratory - Culture, Sports, Health and Society and Exercise Performance, Health, Innovation Platform , Univ. Bourgogne Franche-Comté , Besançon , France
| | - Philippe Gimenez
- a EA4660-C3S Laboratory - Culture, Sports, Health and Society and Exercise Performance, Health, Innovation Platform , Univ. Bourgogne Franche-Comté , Besançon , France
| | - Laurent Mourot
- c EA3920-Prognostic Markers and Regulatory Factors of Heart and Vascular Diseases and Exercise Performance, Health, Innovation Platform , Univ. Bourgogne Franche-Comté , Besançon , France.,d Department of Physical Training , Tomsk Polytechnic University , Tomsk , Russia
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31
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DOYLE-BAKER DOUGLAS, TEMESI JOHN, MEDYSKY MARYE, HOLASH ROBERTJ, MILLET GUILLAUMEY. An Innovative Ergometer to Measure Neuromuscular Fatigue Immediately after Cycling. Med Sci Sports Exerc 2018; 50:375-387. [DOI: 10.1249/mss.0000000000001427] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Finn HT, Rouffet DM, Kennedy DS, Green S, Taylor JL. Motoneuron excitability of the quadriceps decreases during a fatiguing submaximal isometric contraction. J Appl Physiol (1985) 2018; 124:970-979. [PMID: 29357479 DOI: 10.1152/japplphysiol.00739.2017] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
During fatiguing voluntary contractions, the excitability of motoneurons innervating arm muscles decreases. However, the behavior of motoneurons innervating quadriceps muscles is unclear. Findings may be inconsistent because descending cortical input influences motoneuron excitability and confounds measures during exercise. To overcome this limitation, we examined effects of fatigue on quadriceps motoneuron excitability tested during brief pauses in descending cortical drive after transcranial magnetic stimulation (TMS). Participants ( n = 14) performed brief (~5-s) isometric knee extension contractions before and after a 10-min sustained contraction at ~25% maximal electromyogram (EMG) of vastus medialis (VM) on one ( n = 5) or two ( n = 9) days. Electrical stimulation over thoracic spine elicited thoracic motor evoked potentials (TMEP) in quadriceps muscles during ongoing voluntary drive and 100 ms into the silent period following TMS (TMS-TMEP). Femoral nerve stimulation elicited maximal M-waves (Mmax). On the 2 days, either large (~50% Mmax) or small (~15% Mmax) TMS-TMEPs were elicited. During the 10-min contraction, VM EMG was maintained ( P = 0.39), whereas force decreased by 52% (SD 13%) ( P < 0.001). TMEP area remained unchanged ( P = 0.9), whereas large TMS-TMEPs decreased by 49% (SD 28%) ( P = 0.001) and small TMS-TMEPs by 71% (SD 22%) ( P < 0.001). This decline was greater for small TMS-TMEPs ( P = 0.019; n = 9). Therefore, without the influence of descending drive, quadriceps TMS-TMEPs decreased during fatigue. The greater reduction for smaller responses, which tested motoneurons that were most active during the contraction, suggests a mechanism related to repetitive activity contributes to reduced quadriceps motoneuron excitability during fatigue. By contrast, the unchanged TMEP suggests that ongoing drive compensates for altered motoneuron excitability. NEW & NOTEWORTHY We provide evidence that the excitability of quadriceps motoneurons decreases with fatigue. Our results suggest that altered intrinsic properties brought about by repetitive activation of the motoneurons underlie their decreased excitability. Furthermore, we note that testing during voluntary contraction may not reflect the underlying depression of motoneuron excitability because of compensatory changes in ongoing voluntary drive. Thus, this study provides evidence that processes intrinsic to the motoneuron contribute to muscle fatigue of the knee extensors.
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Affiliation(s)
- Harrison T Finn
- Neuroscience Research Australia, Randwick, New South Wales , Australia.,University of New South Wales , Kensington, New South Wales , Australia
| | - David M Rouffet
- Victoria University , Melbourne, Victoria , Australia.,Australian Institute for Musculoskeletal Science, Victoria University , Melbourne , Australia.,Institute of Sport, Exercise, and Active Living, Victoria University , Melbourne , Australia
| | - David S Kennedy
- University of Sydney, Cumberland, New South Wales , Australia.,University of Technology , Ultimo, New South Wales , Australia
| | - Simon Green
- Western Sydney University, Campbelltown, New South Wales , Australia
| | - Janet L Taylor
- Neuroscience Research Australia, Randwick, New South Wales , Australia.,University of New South Wales , Kensington, New South Wales , Australia.,Edith Cowan University , Perth, Western Australia , Australia
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Transcriptome analysis reveals long intergenic non-coding RNAs involved in skeletal muscle growth and development in pig. Sci Rep 2017; 7:8704. [PMID: 28821716 PMCID: PMC5562803 DOI: 10.1038/s41598-017-07998-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 07/06/2017] [Indexed: 02/06/2023] Open
Abstract
Long intergenic non-coding RNAs (lincRNAs) play essential roles in numerous biological processes and are widely studied. The skeletal muscle is an important tissue that plays an essential role in individual movement ability. However, lincRNAs in pig skeletal muscles are largely undiscovered and their biological functions remain elusive. In this study, we assembled transcriptomes using RNA-seq data published in previous studies of our laboratory group and identified 323 lincRNAs in porcine leg muscle. We found that these lincRNAs have shorter transcript length, fewer exons and lower expression level than protein-coding genes. Gene ontology and pathway analyses indicated that many potential target genes (PTGs) of lincRNAs were involved in skeletal-muscle-related processes, such as muscle contraction and muscle system process. Combined our previous studies, we found a potential regulatory mechanism in which the promoter methylation of lincRNAs can negatively regulate lincRNA expression and then positively regulate PTG expression, which can finally result in abnormal phenotypes of cloned piglets through a certain unknown pathway. This work detailed a number of lincRNAs and their target genes involved in skeletal muscle growth and development and can facilitate future studies on their roles in skeletal muscle growth and development.
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Polarity-dependent improvement of maximal-effort sprint cycling performance by direct current stimulation of the central nervous system. Neurosci Lett 2017; 657:97-101. [PMID: 28778807 DOI: 10.1016/j.neulet.2017.07.056] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2016] [Revised: 07/24/2017] [Accepted: 07/30/2017] [Indexed: 01/26/2023]
Abstract
Sprint motor performance, such as in short-distance running or cycling, gradually decreases after reaching a maximum speed or cadence. This may be attributed to the central nervous system. Brain stimulation studies have recently revealed the plastic nature of the human brain and spinal cord, but it is unclear how direct current stimulation (DCS) affects sprint motor performance. To address this issue, we investigated DCS's effect on healthy volunteers' sprint cycling performance. DCS was applied to the lumbar spinal cord (3mA) or the leg area of the motor cortex (2mA) for 15min with 3 different polarities: anodal, cathodal, and sham. After DCS, the subjects performed maximal-effort sprint cycling for 30s under a constant load. Pooled mean power during the 30s was significantly greater after cathodal transcutaneous spinal DCS to the lumbar spinal cord (tsDCS) than anodal or sham tsDCS. The improvement with cathodal stimulation was notable both 0-5 and 20-25s after the performance onset. There were no significant inter-conditional differences in peak power. Pooled mean power was significantly greater after anodal transcranial DCS to the motor cortex (tDCS) than after cathodal tDCS, although mean powers of anodal and sham tDCS were not significantly different. The increase in mean power after cathodal tsDCS could result from a reduction in central fatigue. This stimulus method might improve sprint performance.
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Group III/IV locomotor muscle afferents alter motor cortical and corticospinal excitability and promote central fatigue during cycling exercise. Clin Neurophysiol 2016; 128:44-55. [PMID: 27866119 DOI: 10.1016/j.clinph.2016.10.008] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 08/17/2016] [Accepted: 10/09/2016] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To investigate the influence of group III/IV muscle afferents on the development of central fatigue and corticospinal excitability during exercise. METHODS Fourteen males performed cycling-exercise both under control-conditions (CTRL) and with lumbar intrathecal fentanyl (FENT) impairing feedback from leg muscle afferents. Transcranial magnetic- and cervicomedullary stimulation was used to monitor cortical versus spinal excitability. RESULTS While fentanyl-blockade during non-fatiguing cycling had no effect on motor-evoked potentials (MEPs), cervicomedullary-evoked motor potentials (CMEPs) were 13±3% higher (P<0.05), resulting in a decrease in MEP/CMEP (P<0.05). Although the pre- to post-exercise reduction in resting twitch was greater in FENT vs. CTRL (-53±3% vs. -39±3%; P<0.01), the reduction in voluntary muscle activation was smaller (-2±2% vs. -10±2%; P<0.05). Compared to the start of fatiguing exercise, MEPs and CMEPs were unchanged at exhaustion in CTRL. In contrast, MEPs and MEP/CMEP increased 13±3% and 25±6% in FENT (P<0.05). CONCLUSION During non-fatiguing exercise, group III/IV muscle afferents disfacilitate, or inhibit, spinal motoneurons and facilitate motor cortical cells. In contrast, during exhaustive exercise, group III/IV muscle afferents disfacilitate/inhibit the motor cortex and promote central fatigue. SIGNIFICANCE Group III/IV muscle afferents influence corticospinal excitability and central fatigue during whole-body exercise in humans.
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