Neuromuscular Fatigue and Muscle Damage After a Women’s Rugby Sevens Tournament

2015 ◽  
Vol 10 (6) ◽  
pp. 808-814 ◽  
Author(s):  
Anthea C. Clarke ◽  
Judith M. Anson ◽  
David B. Pyne
Keyword(s):  
Creatine Kinase ◽  
Muscle Damage ◽  
High Speed ◽  
Fold Increase ◽  
Neuromuscular Function ◽  
Neuromuscular Fatigue ◽  
Lower Body ◽  
Countermovement Jump ◽  
Baseline Testing ◽  
Time Distance

Purpose:To examine relationships between on-field game movement patterns and changes in markers of neuromuscular fatigue and muscle damage during a 2-d women’s rugby sevens tournament.Methods:Female national (mean ± SD n = 12, 22.3 ± 2.5 y, 1.67 ± 0.04 m, 65.8 ± 4.6 kg) and state (n = 10, 24.4 ± 4.3 y, 1.67 ± 0.03 m, 66.1 ± 7.9 kg) representative players completed baseline testing for lower-body neuromuscular function (countermovement-jump [CMJ] test), muscle damage (capillary creatine kinase [CK]), perceived soreness, and perceived recovery. Testing was repeated after games on days 1 and 2 of the tournament. GPS (5-Hz) data were collected throughout the tournament (4−6 games/player).Results:National players were involved in greater on-field movements for total time, distance, high-speed running (>5 m/s), and impacts >10 g (effect size [ES] = 0.55−0.97) and displayed a smaller decrement in performance from day 1 to day 2. Despite this, state players had a much greater 4-fold increase (ΔCK = 737 U/L) in CK compared with the 2-fold increase (ΔCK = 502 U/L) in national players (ES = 0.73). Both groups had similar perceived soreness and recovery while CMJ performance was unchanged. High-speed running and impacts >10 g were largely correlated (r = .66−.91) with ΔCK for both groups.Conclusion:A 2-day women’s rugby sevens tournament elicits substantial muscle damage; however, there was little change in lower-body neuromuscular function. Modest increases in CK can largely be attributed to high-speed running and impacts >10 g that players typically endure.

Recovery Kinetics After Speed-Endurance Training in Male Soccer Players

2020 ◽  
Vol 15 (3) ◽  
pp. 395-408
Author(s):  
Theofanis Tzatzakis ◽  
Konstantinos Papanikolaou ◽  
Dimitrios Draganidis ◽  
Panagiotis Tsimeas ◽  
Savvas Kritikos ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Muscle Damage ◽  
Voluntary Contraction ◽  
Neuromuscular Fatigue ◽  
Knee Extensors ◽  
Countermovement Jump ◽  
Jump Performance ◽  
Strength Performance ◽  
Kinetics Of

Purpose: To determine the recovery kinetics of performance, muscle damage, and neuromuscular fatigue following 2 speed-endurance production training (SEPT) protocols in soccer. Methods: Ten well-trained, male soccer athletes randomly completed 3 trials: work-to-rest ratio (SEPT) 1:5, SEPT/1:8, and a control trial. Training load during SEPT was monitored using global positioning system and heart-rate monitors. Performance (isokinetic strength of knee extensors and flexors, speed, and countermovement jump) and muscle damage (delayed-onset muscle soreness [DOMS] and creatine kinase) were evaluated at baseline and at 0, 24, 48 and 72 h posttraining. Maximal voluntary contraction (fatigue index) of knee extensors and flexors was additionally assessed at 1, 2, and 3 h posttraining. Results: Fatigue increased (P < .05) in SEPT/1:5 (∼4–30%) for 3 h and in SEPT/1:8 (∼8–17%) for 2 h. Strength performance declined (P < .05) in both SEPT trials (∼5–20%) for 48 h. Speed decreased (∼4–18%; P < .05) for 72 h in SEPT/1:5 and for 48 h in SEPT/1:8. Countermovement-jump performance decreased (∼7–12%; P < .05) in both SEPT trials for 24 h. DOMS increased (P < .05) in SEPT/1:5 (∼2-fold) for 72 and in SEPT/1:8 (∼1- to 2-fold) for 48 h. Creatine kinase increased (∼1- to 2-fold, P < .05) in both SEPT trials for 72 h. Conclusions: SEPT induces short-term neuromuscular fatigue; provokes a prolonged deterioration of strength (48 h), speed (72 h), and jump performance (24 h); and is associated with a prolonged (72-h) rise of DOMS and creatine kinase. Time for recovery is reduced when longer work-to-rest ratios are applied. Fitness status may affect quality of SEPT and recovery kinetics.

Influence of Neuromuscular Fatigue on Accelerometer Load in Elite Australian Football Players

2013 ◽  
Vol 8 (4) ◽  
pp. 373-378 ◽  
Author(s):  
Stuart J. Cormack ◽  
Mitchell G. Mooney ◽  
Will Morgan ◽  
Michael R. McGuigan
Keyword(s):  
High Speed ◽  
Neuromuscular Fatigue ◽  
Football Players ◽  
Countermovement Jump ◽  
Baseline Measure ◽  
Running Activity ◽  
Australian Football ◽  
Percent Contribution ◽  
Playing Time ◽  
The Impact

Purpose:To determine the impact of neuromuscular fatigue (NMF) assessed from variables obtained during a countermovement jump on exercise intensity measured with triaxial accelerometers (load per minute [LPM]) and the association between LPM and measures of running activity in elite Australian Football.Methods:Seventeen elite Australian Football players performed the Yo-Yo Intermittent Recovery Test level 2 (Yo-Yo IR2) and provided a baseline measure of NMF (flight time:contraction time [FT:CT]) from a countermovement jump before the season. Weekly samples of FT:CT, coaches’ rating of performance (votes), LPM, and percent contribution of the 3 vectors from the accelerometers in addition to high-speed-running meters per minute at >15 km/h and total distance relative to playing time (m/min) from matches were collected. Samples were divided into fatigued and nonfatigued groups based on reductions in FT:CT. Percent contributions of vectors to LPM were assessed to determine the likelihood of a meaningful difference between fatigued and nonfatigued groups. Pearson correlations were calculated to determine relationships between accelerometer vectors and running variables, votes, and Yo-Yo IR2 score.Results:Fatigue reduced the contribution of the vertical vector by (mean ± 90% CI) –5.8% ± 6.1% (86% likely) and the number of practically important correlations.Conclusions:NMF affects the contribution of individual vectors to total LPM, with a likely tendency toward more running at low speed and less acceleration. Fatigue appears to limit the influence of the aerobic and anaerobic qualities assessed via the Yo-Yo IR2 test on LPM and seems implicated in pacing.

scholarly journals Changes in markers of fatigue following a competitive match in elite academy rugby union players

2016 ◽  
Vol 28 (1) ◽  
pp. 2-5 ◽  
Author(s):  
G Roe
Keyword(s):  
Creatine Kinase ◽  
Whole Blood ◽  
Sports Injuries ◽  
Well Being ◽  
Rugby Union ◽  
Flight Time ◽  
Lower Body ◽  
Countermovement Jump ◽  
Mean Power ◽  
Push Up

Background: Post-match fatigue has yet to be investigated inacademy rugby union players.Objectives: To determine the magnitude of change in upper-(plyometric push-up (PP) flight-time) and lower-body(countermovement jump (CMJ) mean power) neuromuscularfunction (NMF), whole blood creatine kinase (CK) and perceptionof well-being following a competitive match in academy rugbyunion players.Methods: Fourteen academy rugby union players participatedin the study. Measures were taken 2 h pre-match (baseline) andimmediately post-match. Further testing was also undertaken at24-, 48- and 72 h respectively post-match. Changes in measuresfrom baseline were determined using magnitude-based inferences.Results: Decreases in CMJ mean power were likely substantialimmediately (-5.5±3.3%) post-match, very likely at 24 h (-7±3.9),likely at 48 h (-5.8±5.4), while likely trivial at 72 h (-0.8±3.8)post-match. PP flight-time was very likely reduced immediately(-15.3±7.3%) and 24 h (-11.5±5.7%) post-match, while possiblyincreased at 48 h (3.5±6.0%) and likely trivial at 72 h (-0.9±5.4%)post-match. Decreases in perception of well-being were almostcertainly substantial at 24 h (-24.0±4.3%), very likely at 48 h(-8.3±5.9%), and likely substantial at 72 h (-3.6±3.7%) post-match.Increases in CK were almost certainly substantial immediately(138.5±33%), 24 h (326±78%) and 48 h (176±62%) post-match,while very likely substantial at 72 h (57±35%) post-match.Conclusion: These findings demonstrate the transient andmultidimensional nature of post-match fatigue in academyrugby union players. Furthermore, the results demonstrate theindividual nature of recovery, with many players demonstratingdifferent recovery profiles from the group average.Keywords: collision sport, monitoring, sports injuries

scholarly journals Relationship between gastro-intestinal complaints and endotoxaemia, cytokine release and the acute-phase reaction during and after a long-distance triathlon in highly trained men

1999 ◽  
Vol 98 (1) ◽  
pp. 47-55 ◽  
Author(s):  
A. E. JEUKENDRUP ◽  
K. VET-JOOP ◽  
A. STURK ◽  
J. H. J. C. STEGEN ◽  
J. SENDEN ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Muscle Damage ◽  
Acute Phase ◽  
Endurance Exercise ◽  
Acute Phase Response ◽  
Fold Increase ◽  
C Reactive Protein ◽  
Long Distance ◽  
Reactive Protein ◽  
Ultra Endurance

The aim of the present study was to establish whether gastro-intestinal (GI) complaints observed during and after ultra-endurance exercise are related to gut ischaemia-associated leakage of endotoxins [lipopolysaccharide (LPS)] into the circulation and associated cytokine production. Therefore we collected blood samples from 29 athletes before, immediately after, and 1, 2 and 16 h after a long-distance triathlon for measurement of LPS, tumour necrosis factor-α and interleukin-6 (IL-6). As the cytokine response would trigger an acute-phase response, characteristic variables of these responses were also measured, along with creatine kinase (CK) to obtain an indicator of muscle damage. There was a high incidence (93% of all participants) of GI symptoms; 45% reported severe complaints and 7% of the participants abandoned the race because of severe GI distress. Mild endotoxaemia (5–15 pg/ml) was evident in 68% of the athletes immediately after the race, as also indicated by a reduction in IgG anti-LPS levels. In addition, we observed production of IL-6 (27–fold increase immediately after the race), leading to an acute-phase response (20-fold increase in C-reactive protein and 12% decrease in pre-albumin 16 h after the race). The extent of endotoxaemia was not correlated with the GI complaints or the IL-6 response, but did show a correlation with the elevation in C-reactive protein (rs 0.389; P = 0.037). Creatine kinase levels were increased significantly immediately post-race, and increased further in the follow-up period. Creatine kinase levels did not correlate with those of either IL-6 or C-reactive protein. It is therefore concluded that LPS does enter the circulation after ultra-endurance exercise and may, together with muscle damage, be responsible for the increased cytokine response and hence GI complaints in these athletes.

scholarly journals Workload, Fatigue, and Muscle Damage in an Under-20 Rugby Union Team Over an Intensified International Tournament

2018 ◽  
Vol 13 (8) ◽  
pp. 1059-1066 ◽  
Author(s):  
Mathieu Lacome ◽  
Christopher Carling ◽  
Jean-Philippe Hager ◽  
Gerard Dine ◽  
Julien Piscione
Keyword(s):  
Muscle Damage ◽  
High Speed ◽  
Perceived Exertion ◽  
Well Being ◽  
Rugby Union ◽  
Rating Of Perceived Exertion ◽  
Exposure Group ◽  
Progressive Decrease ◽  
Countermovement Jump ◽  
Match Play

Purpose:To examine the effects of an intensified tournament on workload, perceptual and neuromuscular fatigue, and muscle-damage responses in an international under-20 rugby union team.Methods:Players were subdivided into a high-exposure group (HEG, n = 13) and a low-exposure group (LEG, n = 11) according to match-play exposure time. Measures monitored over the 19-d period included training session (n = 10) and match (n = 5) workload determined via global positioning systems and session rating of perceived exertion. Well-being scores, countermovement jump height performance, and blood creatine kinase concentrations were collected at various time points.Results:Analysis of workload cumulated across the tournament entirety for training and match play combined showed that high-speed running distance was similar between groups, while a very likely larger session rating of perceived exertion load was reported in HEG vs LEG. In HEG, high-speed activity fluctuated across the 5 successive matches, albeit with no clear trend for a progressive decrease. No clear tendency for a progressive decrease in well-being scores prior to or following matches was observed in either group. In HEG, trivial to possibly small reductions in postmatch countermovement jump performance were observed, while unclear to most likely moderate increases in prematch blood creatine kinase concentrations occurred until prior to match 4.Conclusions:The magnitude of match-to-match changes in external workload, perceptual and neuromuscular fatigue, and muscle damage was generally unclear or small. These results suggest that irrespective of exposure time to match play players generally maintained performance and readiness to play across the intensified tournament. These findings support the need for holistic systematic player-monitoring programs.

scholarly journals Effects of Ultratrail Running on Neuromuscular Function, Muscle Damage and Hydration Status. Differences According to Training Level

2021 ◽  
Vol 18 (10) ◽  
pp. 5119
Author(s):  
Francisco Pradas ◽  
David Falcón ◽  
Carlos Peñarrubia-Lozano ◽  
Víctor Toro-Román ◽  
Luis Carrasco ◽  
...  
Keyword(s):  
Muscle Damage ◽  
Neuromuscular Function ◽  
Hydration Status ◽  
Training Level ◽  
Countermovement Jump ◽  
Squat Jump ◽  
Acute Response ◽  
High Level Group ◽  
High Level ◽  
Level Group

The status of trail running races has exponentially grown in recent years. The present study aimed to: (a) evaluate the acute response of ultratrail racing in terms of neuromuscular function, muscle damage and hydration status; (b) analyze if responses could differ according to training levels. Twenty runners participated in the present study. The participants were divided into amateur training level (n = 10; 43.30 ± 4.52 years) or high level competitors (n = 10; 41.40 ± 6.18). Neuromuscular response (squat jump, countermovement jump and Abalakov jump), muscle damage (alanine aminotransferase, bilirubin, creatine kinase and leukocytes) and hydration status (sodium and creatinine) were evaluated before and after the Guara Somontano Ultratrail Race (108 km distance, with an accumulated slope of 5800 m). The height and power achieved by vertical jumps were lower after the race (p < 0.001). The post-race muscle damage and creatinine parameters increased in both groups (p < 0.001). The high-level group obtained lower percentages of change in squat jump and countermovement jump than the amateur-level group (p < 0.05). However, the increase in creatinine was greater for the high-level group (p < 0.05). Ultratrail racing reduces neuromuscular function and increases muscle damage. High-level runners showed less neuromuscular fatigue compared to amateur ones.

scholarly journals 145 President Oral Presentation Pick: Prenatal stress increases skeletal muscle mitochondrial volume density and function in yearling Brahman calves

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 120-121
Author(s):  
Chloey P Guy ◽  
Catherine L Wellman ◽  
David G Riley ◽  
Charles R Long ◽  
Ron D Randel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Creatine Kinase ◽  
Muscle Damage ◽  
Prenatal Stress ◽  
Citrate Synthase ◽  
Volume Density ◽  
Assembly Factor ◽  
Mitochondrial Volume ◽  
Mitochondrial Volume Density ◽  
And Function

Abstract We previously determined that prenatal stress (PNS) differentially affected methylation of DNA from leukocytes of 28-d-old calves. Specifically, COX14 (cytochrome c oxidase (COX) assembly factor) and CKMT1B (mitochondrial creatine kinase U-type) were hypomethylated and COA5 (COX assembly factor 5), COX5A (COX subunit 5A), NRF1 (nuclear respiratory factor 1), and GSST1 (glutathione S-transferase theta-1) were hypermethylated in PNS compared to non-PNS calves (P ≤ 0.05). Our current objective was to test the hypothesis that PNS exhibit impaired mitochondrial function and greater oxidative stress than non-PNS calves. Blood and longissimus dorsi muscle samples were collected from yearling Brahman calves whose mothers were stressed by 2 h transportation at 60, 80, 100, 120, and 140 days of gestation (PNS; 8 bulls, 6 heifers) and non-PNS calves (4 bulls, 6 heifers). Serum was evaluated for the stress hormone, cortisol, and muscle damage marker, creatine kinase; muscle was analyzed for mitochondrial volume density and function by citrate synthase (CS) and COX activities, respectively, concentration of malondialdehyde, a lipid peroxidation marker, and activity of the antioxidant, superoxide dismutase (SOD). Data were analyzed using mixed linear models with treatment and sex as fixed effects. Serum cortisol was numerically higher in PNS than non-PNS calves but was not statistically different. Muscle CS and COX activities relative to protein were greater in PNS than non-PNS calves (P ≤ 0.03), but COX relative to CS activity was similar between groups. Activity of COX was greater in bulls than heifers (P = 0.03), but no other measure was affected by sex. All other measures were unaffected by PNS. Prenatal stress did not affect markers of muscle damage and oxidative stress in yearling Brahman calves at rest but mitochondrial volume density and function were greater in PNS calves. Acute stressors induce oxidative stress, so implications of differences in mitochondria in PNS calves following a stressor should be investigated.

scholarly journals 2D-3D integration of hexagonal boron nitride and a high-κ dielectric for ultrafast graphene-based electro-absorption modulators

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hitesh Agarwal ◽  
Bernat Terrés ◽  
Lorenzo Orsini ◽  
Alberto Montanaro ◽  
Vito Sorianello ◽  
...  
Keyword(s):  
Boron Nitride ◽  
Hafnium Oxide ◽  
High Speed ◽  
Hexagonal Boron Nitride ◽  
Temperature Stability ◽  
Cost Effective ◽  
Fold Increase ◽  
Building Blocks ◽  
High Quality ◽  
New Device

AbstractElectro-absorption (EA) waveguide-coupled modulators are essential building blocks for on-chip optical communications. Compared to state-of-the-art silicon (Si) devices, graphene-based EA modulators promise smaller footprints, larger temperature stability, cost-effective integration and high speeds. However, combining high speed and large modulation efficiencies in a single graphene-based device has remained elusive so far. In this work, we overcome this fundamental trade-off by demonstrating the 2D-3D dielectric integration in a high-quality encapsulated graphene device. We integrated hafnium oxide (HfO2) and two-dimensional hexagonal boron nitride (hBN) within the insulating section of a double-layer (DL) graphene EA modulator. This combination of materials allows for a high-quality modulator device with high performances: a ~39 GHz bandwidth (BW) with a three-fold increase in modulation efficiency compared to previously reported high-speed modulators. This 2D-3D dielectric integration paves the way to a plethora of electronic and opto-electronic devices with enhanced performance and stability, while expanding the freedom for new device designs.

scholarly journals High-quality brain perfusion SPECT images may be achieved with a high-speed recording using 360° CZT camera

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Manon Bordonne ◽  
Mohammad B. Chawki ◽  
Pierre-Yves Marie ◽  
Timothée Zaragori ◽  
Véronique Roch ◽  
...  
Keyword(s):  
Image Quality ◽  
High Speed ◽  
Brain Perfusion ◽  
Fold Increase ◽  
Brain Structures ◽  
Czt Camera ◽  
Recording Time ◽  
Brain Perfusion Spect ◽  
Central Brain ◽  
Perfusion Spect

Abstract Objective The aim of this study was to compare brain perfusion SPECT obtained from a 360° CZT and a conventional Anger camera. Methods The 360° CZT camera utilizing a brain configuration, with 12 detectors surrounding the head, was compared to a 2-head Anger camera for count sensitivity and image quality on 30-min SPECT recordings from a brain phantom and from 99mTc-HMPAO brain perfusion in 2 groups of 21 patients investigated with the CZT and Anger cameras, respectively. Image reconstruction was adjusted according to image contrast for each camera. Results The CZT camera provided more than 2-fold increase in count sensitivity, as compared with the Anger camera, as well as (1) lower sharpness indexes, giving evidence of higher spatial resolution, for both peripheral/central brain structures, with respective median values of 5.2%/3.7% versus 2.4%/1.9% for CZT and Anger camera respectively in patients (p < 0.01), and 8.0%/6.9% versus 6.2%/3.7% on phantom; and (2) higher gray/white matter contrast on peripheral/central structures, with respective ratio median values of 1.56/1.35 versus 1.11/1.20 for CZT and Anger camera respectively in patients (p < 0.05), and 2.57/2.17 versus 1.40/1.12 on phantom; and (3) no change in noise level. Image quality, scored visually by experienced physicians, was also significantly higher on CZT than on the Anger camera (+ 80%, p < 0.01), and all these results were unchanged on the CZT images obtained with only a 15 min recording time. Conclusion The 360° CZT camera provides brain perfusion images of much higher quality than a conventional Anger camera, even with high-speed recordings, thus demonstrating the potential for repositioning brain perfusion SPECT to the forefront of brain imaging.

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