1
|
Nishikawa T, Hirono T, Holobar A, Kunugi S, Okudaira M, Ohya T, Watanabe K. Acute effects of caffeine or quercetin ingestion on motor unit firing pattern before and after resistance exercise. Eur J Appl Physiol 2024:10.1007/s00421-023-05376-0. [PMID: 38193908 DOI: 10.1007/s00421-023-05376-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 11/14/2023] [Indexed: 01/10/2024]
Abstract
The aim of the present study was to investigate the acute effect of caffeine or quercetin ingestion on motor unit firing patterns and muscle contractile properties before and after resistance exercise. High-density surface electromyography (HDs-EMG) during submaximal contractions and electrically elicited torque in knee extensor muscles were measured before (PRE) and 60 min after (POST1) ingestion of caffeine, quercetin glycosides, or placebo, and after resistance exercise (POST2) in ten young males. The Convolution Kernel Compensation technique was used to identify individual motor units of the vastus lateralis muscle for the recorded HDs-EMG. Ingestion of caffeine or quercetin induced significantly greater decreases in recruitment thresholds (RTs) from PRE to POST1 compared with placebo (placebo: 94.8 ± 9.7%, caffeine: 84.5 ± 16.2%, quercetin: 91.9 ± 36.7%), and there were significant negative correlations between the change in RTs (POST1-PRE) and RT at PRE for caffeine (rs = - 0.448, p < 0.001) and quercetin (rs = - 0.415, p = 0.003), but not placebo (rs = - 0.109, p = 0.440). Significant positive correlations between the change in firing rates (POST2-POST1) and RT at PRE were noted with placebo (rs = 0.380, p = 0.005) and quercetin (rs = 0.382, p = 0.007), but not caffeine (rs = 0.069, p = 0.606). No significant differences were observed in electrically elicited torque among the three conditions. These results suggest that caffeine or quercetin ingestion alters motor unit firing patterns after resistance exercise in different threshold-dependent manners in males.
Collapse
Affiliation(s)
- Taichi Nishikawa
- Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
| | - Tetsuya Hirono
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
| | - Aleš Holobar
- Faculty of Electrical Engineering and Computer Science, University of Maribor, Maribor, Slovenia
| | - Shun Kunugi
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
- Center for General Education, Aichi Institute of Technology, Toyota, Japan
| | - Masamichi Okudaira
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan
| | - Toshiyuki Ohya
- Laboratory for Exercise Physiology and Biomechanics, Graduate School of Health and Sport Sciences, Chukyo University, Toyota, Japan
| | - Kohei Watanabe
- Laboratory of Neuromuscular Biomechanics, School of Health and Sport Sciences, Chukyo University, Kaizu-Cho, Tokodachi, Toyota, 470-0093, Japan.
| |
Collapse
|
2
|
Taylor CA, Kopicko BH, Negro F, Thompson CK. Sex differences in the detection of motor unit action potentials identified using high-density surface electromyography. J Electromyogr Kinesiol 2022; 65:102675. [PMID: 35728511 PMCID: PMC10807372 DOI: 10.1016/j.jelekin.2022.102675] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 05/09/2022] [Accepted: 06/01/2022] [Indexed: 12/18/2022] Open
Abstract
Sex-related disparities in force production of humans have been widely observed. Previous literature has attributed differences in peripheral traits, such as muscle size, to explain these disparities. However, less is known about potential sex-related differences in central neuromuscular traits and many comparable studies, not exploring sex-related differences, exhibit a selection-bias in the recruitment of subjects making the generalization of their findings difficult. Utilizing high-density electromyography arrays and motor unit (MU) decomposition, the aim of the current study is to compare MU yield and discharge properties of the tibialis anterior between male and female humans. Twenty-four subjects (10 females) performed two submaximal (20%) isometric dorsiflexion contractions. On average, males yielded nearly twice the amount of MUs as females. Further, females had significantly higher MU discharge rate, lower MU action potential amplitude, and lower MU action potential frequency content than males despite similar levels of torque and MU discharge variability. These findings suggest differences in central neuromuscular control of force production between sexes; however, it is unclear how lower yield counts affect the accuracy of these results.
Collapse
Affiliation(s)
- Christopher A Taylor
- Department of Health and Rehabilitation Sciences, Temple University, United States
| | - Brian H Kopicko
- Department of Health and Rehabilitation Sciences, Temple University, United States
| | - Francesco Negro
- Department of Clinical and Experimental Sciences, Università degli Studi di Brescia, Italy
| | | |
Collapse
|
3
|
Martinez-Valdes E, Laine CM, Falla D, Mayer F, Farina D. High-density surface electromyography provides reliable estimates of motor unit behavior. Clin Neurophysiol 2015; 127:2534-41. [PMID: 26778718 DOI: 10.1016/j.clinph.2015.10.065] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 08/29/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To assess the intra- and inter-session reliability of estimates of motor unit behavior and muscle fiber properties derived from high-density surface electromyography (HDEMG). METHODS Ten healthy subjects performed submaximal isometric knee extensions during three recording sessions (separate days) at 10%, 30%, 50% and 70% of their maximum voluntary effort. The discharge timings of motor units of the vastus lateralis and medialis muscles were automatically identified from HDEMG by a decomposition algorithm. We characterized the number of detected motor units, their discharge rates, the coefficient of variation of their inter-spike intervals (CoVisi), the action potential conduction velocity and peak-to-peak amplitude. Reliability was assessed for each motor unit characteristics by intra-class correlation coefficient (ICC). Additionally, a pulse-to-noise ratio (PNR) was calculated, to verify the accuracy of the decomposition. RESULTS Good to excellent reliability within and between sessions was found for all motor unit characteristics at all force levels (ICCs>0.8), with the exception of CoVisi that presented poor reliability (ICC<0.6). PNR was high and similar for both muscles with values ranging between 45.1 and 47.6dB (accuracy>95%). CONCLUSION Motor unit features can be assessed non-invasively and reliably within and across sessions over a wide range of force levels. SIGNIFICANCE These results suggest that it is possible to characterize motor units in longitudinal intervention studies.
Collapse
Affiliation(s)
- E Martinez-Valdes
- Department of Sports Medicine and Sports Orthopaedics, University of Potsdam, Potsdam, Germany
| | - C M Laine
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen (BFNT), Bernstein Centre for Computational Neuroscience (BCCN), University Medical Center Göttingen, Georg-August University, Göttingen, Germany
| | - D Falla
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen (BFNT), Bernstein Centre for Computational Neuroscience (BCCN), University Medical Center Göttingen, Georg-August University, Göttingen, Germany; Pain Clinic, Center for Anesthesiology, Emergency and Intensive Care Medicine, University Hospital Göttingen, Göttingen, Germany
| | - F Mayer
- Department of Sports Medicine and Sports Orthopaedics, University of Potsdam, Potsdam, Germany
| | - D Farina
- Department of Neurorehabilitation Engineering, Bernstein Focus Neurotechnology Göttingen (BFNT), Bernstein Centre for Computational Neuroscience (BCCN), University Medical Center Göttingen, Georg-August University, Göttingen, Germany.
| |
Collapse
|