Perceived exertion during muscle fatigue as reflected in movement-related cortical potentials

Neuroreport ◽  
2017 ◽  
Vol 28 (3) ◽  
pp. 115-122 ◽  
Author(s):  
Feng Guo ◽  
Yong-Jun Sun ◽  
Ri-Hui Zhang
Keyword(s):  
Muscle Fatigue ◽  
Perceived Exertion ◽  
Cortical Potentials

scholarly journals Effects of a Ketogenic Diet on Muscle Fatigue in Healthy, Young, Normal-Weight Women: A Randomized Controlled Feeding Trial

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 955 ◽  
Author(s):  
Anna Sjödin ◽  
Fredrik Hellström ◽  
EwaCarin Sehlstedt ◽  
Michael Svensson ◽  
Jonas Burén
Keyword(s):  
Muscle Fatigue ◽  
Mixed Models ◽  
Perceived Exertion ◽  
Daily Life ◽  
Control Diet ◽  
Normal Weight ◽  
Ratings Of Perceived Exertion ◽  
Daily Life Activities ◽  
Low Carbohydrate ◽  
Handgrip Test

Ketogenic low-carbohydrate high-fat (LCHF) diets are increasingly popular in broad sections of the population. The main objective of this study was to evaluate the effects of a non-energy-restricted ketogenic LCHF diet on muscle fatigue in healthy, young, and normal-weight women. Twenty-four women were randomly allocated to a 4-week ketogenic LCHF diet followed by a 4-week control diet (a National Food Agency recommended diet), or the reverse sequence due to the crossover design. Treatment periods were separated by a 15 week washout period. Seventeen women completed the study and were included in the analyses. Treatment effects were evaluated using mixed models. The ketogenic LCHF diet had no effect on grip strength or time to fatigue, measured with handgrip test (day 24–26). However, cycling time to fatigue decreased with almost two minutes (−1.85 min 95% CI:[−2.30;−1.40]; p < 0.001) during incremental cycling (day 25–27), accommodated with higher ratings of perceived exertion using the Borg scale (p < 0.01). Participants’ own diary notes revealed experiences of muscle fatigue during daily life activities, as well as during exercise. We conclude that in young and healthy women, a ketogenic LCHF diet has an unfavorable effect on muscle fatigue and might affect perceived exertion during daily life activities.

scholarly journals Cardiorespiratory, Metabolic and Muscular Responses during a Video-Recorded Aerobic Dance Session on an Air Dissipation Platform

2020 ◽  
Vol 17 (24) ◽  
pp. 9511
Author(s):  
Alessandra Moreira-Reis ◽  
José Luis Maté-Muñoz ◽  
Juan Hernández-Lougedo ◽  
Pablo García-Fernández ◽  
Eulogio Pleguezuelos-Cobo ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Perceived Exertion ◽  
Pulmonary Ventilation ◽  
Muscular Fatigue ◽  
Metabolic Responses ◽  
Hard Surface ◽  
Aerobic Dance ◽  
Jump Test ◽  
Before And After ◽  
Lactate Levels

Background: Aerobic dance (AD) is an appropriate physical activity for improving cardiorespiratory fitness. This study aimed to compare cardiorespiratory and metabolic responses, and muscle fatigue between an air dissipation platform (ADP) and a hard surface during a video-recorded AD session. Methods: 25 healthy young women (23.3 ± 2.5 years) completed three sessions. In session 1, participants performed an incremental test to exhaustion on a treadmill. One week after session 1, participants were randomly assigned in a crossover design to perform video-recorded AD sessions on an ADP and on a hard surface (sessions 2 and 3). Cardiorespiratory and metabolic responses were assessed during AD sessions. Muscular fatigue was measured before and after AD sessions by a countermovement jump test. Results: Significantly higher heart rate, respiratory exchange ratio, pulmonary ventilation, ventilatory oxygen equivalent, and ventilatory carbon dioxide equivalent were observed on an ADP than on a hard surface (p < 0.05). Despite a significant increase in lactate levels on an ADP (p ≤ 0.01), muscular fatigue and perceived exertion rating were similar on both surfaces (p > 0.05). Conclusions: Video-recorded AD on an ADP increased the cardioventilatory and metabolic responses compared to a hard surface, preventing further muscle fatigue.

scholarly journals Maximal repetition performance, rating of perceived exertion, and muscle fatigue during paired set training performed with different rest intervals

2015 ◽  
Vol 13 (2) ◽  
pp. 104-110 ◽  
Author(s):  
Marianna de Freitas Maia ◽  
Gabriel Andrade Paz ◽  
Humberto Miranda ◽  
Vicente Lima ◽  
Claudio Melibeu Bentes ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Perceived Exertion ◽  
Rating Of Perceived Exertion ◽  
Performance Rating ◽  
Rest Intervals

Locomotor muscle fatigue increases cardiorespiratory responses and reduces performance during intense cycling exercise independently from metabolic stress

2008 ◽  
Vol 294 (3) ◽  
pp. R874-R883 ◽  
Author(s):  
Samuele M. Marcora ◽  
Andrea Bosio ◽  
Helma M. de Morree
Keyword(s):  
Muscle Fatigue ◽  
Exercise Performance ◽  
High Intensity ◽  
Perceived Exertion ◽  
Metabolic Stress ◽  
Motor Command ◽  
Time To Exhaustion ◽  
Test Duration ◽  
Cardiorespiratory Responses ◽  
Locomotor Muscles

Locomotor muscle fatigue, defined as an exercise-induced reduction in maximal voluntary force, occurs during prolonged exercise, but its effects on cardiorespiratory responses and exercise performance are unknown. In this investigation, a significant reduction in locomotor muscle force (−18%, P < 0.05) was isolated from the metabolic stress usually associated with fatiguing exercise using a 100-drop-jumps protocol consisting of one jump every 20 s from a 40-cm-high platform. The effect of this treatment on time to exhaustion during high-intensity constant-power cycling was measured in study 1 ( n = 10). In study 2 ( n = 14), test duration (871 ± 280 s) was matched between fatigue and control condition (rest). In study 1, locomotor muscle fatigue caused a significant curtailment in time to exhaustion (636 ± 278 s) compared with control (750 ± 281 s) ( P = 0.003) and increased cardiac output. Breathing frequency was significantly higher in the fatigue condition in both studies despite similar oxygen consumption and blood lactate accumulation. In study 2, high-intensity cycling did not induce further fatigue to eccentrically-fatigued locomotor muscles. In both studies, there was a significant increase in heart rate in the fatigue condition, and perceived exertion was significantly increased in study 2 compared with control. These results suggest that locomotor muscle fatigue has a significant influence on cardiorespiratory responses and exercise performance during high-intensity cycling independently from metabolic stress. These effects seem to be mediated by the increased central motor command and perception of effort required to exercise with weaker locomotor muscles.

Effects of handle height and load on the endurance time for simulated demolition tasks

Work ◽  
2021 ◽  
pp. 1-10
Author(s):  
Kai Way Li ◽  
Wenbao Li ◽  
Lu Peng
Keyword(s):  
Muscle Fatigue ◽  
Regression Models ◽  
Perceived Exertion ◽  
Ratings Of Perceived Exertion ◽  
Endurance Time ◽  
Factors Affecting ◽  
The Mean ◽  
Forceful Exertion ◽  
Load Conditions ◽  
Do So

BACKGROUND: Manual demolition tasks are heavy physical demanding tasks which involve forceful exertion of sustained pushing. They result in muscle fatigue which could lead to musculoskeletal disorders. Assessments of maximum endurance time (MET) are essential in understanding the developing of muscle fatigue for these tasks. OBJECTIVE: The objectives of this study were to determine the effects of handle height and load conditions on the MET, and to establish MET models for the simulated demolition tasks. METHODS: Twenty three male participants performed simulated demolition tasks under three loads and three handle heights conditions until they could not do so any longer. Their METs and ratings of perceived exertion were recorded and analyzed. RESULTS: The results showed that both load and handle height were significant (p <  0.0001) factors affecting the MET. Regression models to predict the MET under handle height and load conditions were established. The mean absolute deviations of these models were between 1.91 and 4.84 min. CONCLUSION: The MET models established may be used to estimate the MET which may be adopted in work/rest arrangement for demolition tasks using a handheld demolition hammer.

scholarly journals Muscle Fatigue When Swimming Intermittently Above and Below Critical Speed

2016 ◽  
Vol 11 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Jeanne Dekerle ◽  
James Paterson
Keyword(s):  
Muscle Fatigue ◽  
Critical Speed ◽  
Perceived Exertion ◽  
Recovery Period ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Rating Of Perceived Exertion ◽  
Stroke Rate ◽  
Stroke Length ◽  
Isokinetic Testing

Purpose:To examine muscle fatigue of the shoulder internal rotators alongside swimming biomechanics during long-duration submaximal swimming sets performed in 2 different speed domains.Methods:Eight trained swimmers (mean ± SD 20.5 ± 0.9 y, 173 ± 10 cm, 71.3 ± 10.0 kg) raced over 3 distances (200-, 400-, 800-m races) for determination of critical speed (CS; slope of the distance–time relationship). After a familiarization with muscle isokinetic testing, they subsequently randomly performed 2 constant-speed efforts (6 × 5-min blocks, 2.5-min recovery) 5% above (T105) and 5% below CS (T95) with maximal voluntary contractions recorded between swimming blocks.Results:Capillary blood lactate concentration ([La]), rating of perceived exertion (RPE), peak torque, stroke length, and stroke rate were maintained throughout T95 (P < .05). [La], RPE, and stroke rate increased alongside concomitant decreases in maximal torque and stroke length during T105 (P < .05) with incapacity of the swimmers to maintain the pace for longer than ~20 min. For T105, changes in maximal torque (35.0 ± 14.9 to 25.8 ± 12.1 Nm) and stroke length (2.66 ± 0.36 to 2.23 ± 0.24 m/cycle) were significantly correlated (r = .47, P < .05).Conclusion:While both muscle fatigue (shoulder internal rotators) and task failure occur when swimming at a pace greater than CS, the 2.5-min recovery period during the sub-CS set possibly alleviated the development of muscle fatigue for the pace to be sustainable for 6 × 5 min at 95% of CS. A causal relationship between reduction in stroke length and loss of muscle strength should be considered very cautiously in swimming.

scholarly journals Modeling and Validation of Fatigue and Recovery of Muscles for Manual Demolition Tasks

2022 ◽  
Vol 19 (2) ◽  
pp. 930
Author(s):  
Cannan Yi ◽  
Fan Tang ◽  
Kai-Way Li ◽  
Hong Hu ◽  
Huali Zuo ◽  
...  
Keyword(s):  
Muscle Fatigue ◽  
Fatigue Test ◽  
Perceived Exertion ◽  
Recovery Test ◽  
Work Related ◽  
Before And After ◽  
Recovery Models ◽  
Human Participants ◽  
Forceful Exertion ◽  
Fatigue Recovery

Manual demolition tasks are heavy, physically demanding tasks that could cause muscle fatigue accumulation and lead to work-related musculoskeletal disorders (WMSDs). Fatigue and recovery models of muscles are essential in understanding the accumulation and the reduction in muscle fatigue for forceful exertion tasks. This study aims to explore the onset of muscle fatigue under different work/rest arrangements during manual demolition tasks and the offset of fatigue over time after the tasks were performed. An experiment, including a muscle fatigue test and a muscle fatigue recovery test, was performed. Seventeen male adults without experience in demolition hammer operation were recruited as human participants. Two demolition hammers (large and small) were adopted. The push force was either 20 or 40 N. The posture mimicked that of a demolition task on a wall. In the muscle fatigue test, the muscle strength (MS) before and after the demolition task, maximum endurance time (MET), and the Borg category-ratio-10 (CR-10) ratings of perceived exertion after the demolition task were measured. In the muscle fatigue recovery test, MS and CR-10 at times 1, 2, 3, 4, 5, and 6 min were recorded. Statistical analyses were performed to explore the influence of push force and the weight of the tool on MS, MET, and CR-10. Both muscle fatigue models and muscle fatigue recovery models were established and validated. The results showed that push force affected MET significantly (p < 0.05). The weight of the tool was significant (p < 0.05) only on the CR-10 rating after the first pull. During the muscle fatigue recovery test, the MS increase and the CR-10 decrease were both significant (p < 0.05) after one or more breaks. Models of MET and MS prediction were established to assess muscle fatigue recovery, respectively. The absolute (AD) and relative (RD) deviations of the MET model were 1.83 (±1.94) min and 34.80 (±31.48)%, respectively. The AD and RD of the MS model were 1.39 (±0.81) N and 1.9 (±1.2)%, respectively. These models are capable of predicting the progress and recovery of muscle fatigue, respectively, and may be adopted in work/rest arrangements for novice workers performing demolition tasks.

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