Neuromuscular and perceptual mechanisms of fatigue accompanying task failure in response to moderate-, heavy-, severe-, and extreme-intensity cycling

Journal of Applied Physiology, Journal Year: 2022, Volume and Issue: 133(2), P. 323 - 334

Published: June 30, 2022

A comprehensive characterization of neuromuscular and perceptual mechanisms fatigue at task failure following exercise across the entire intensity spectrum is lacking. This study evaluated extent peripheral central fatigue, corresponding attributes, cycling within moderate-(MOD), heavy-(HVY), severe-(SVR), extreme-(EXT) domains. After a ramp-incremental test, 11 young males performed four constant-power output trials to limit tolerance (Tlim) 4 distinct domain-specific workloads. These were preceded followed by 5-s knee-extension maximal voluntary contractions (MVCs) femoral nerve electrical stimuli quantify fatigue. In addition, measures including ratings global legs pain, dyspnea, perceived effort (RPE) also collected. At Tlim, reductions in MVC independent (P > 0.05). However, was greater EXT SVR progressively, but distinctively, lower HVY MOD < Central similar after SVR, HVY, MOD, absent subjective progressively higher with intensities, whereas pain dyspnea intensities. On other hand, RPE EXT, not MOD. The findings demonstrate that highly domain-specific, not. Sensations such as may integrate sense determine manner specific each domain.NEW & NOTEWORTHY Together physiological responses, mechanisms, related accompanying are suggested be dependent on domain which sustained. Here, we show demonstrates high specificity, specificity for breathlessness demonstrated might have contributed reaching levels and, thus, failure.

Language: Английский

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Evaluating the Accuracy of Using Fixed Ranges of METs to Categorize Exertional Intensity in a Heterogeneous Group of Healthy Individuals: Implications for Cardiorespiratory Fitness and Health Outcomes

Sports Medicine, Journal Year: 2021, Volume and Issue: 51(11), P. 2411 - 2421

Published: April 26, 2021

Language: Английский

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Interaction of Factors Determining Critical Power

Sports Medicine, Journal Year: 2023, Volume and Issue: 53(3), P. 595 - 613

Published: Jan. 9, 2023

Abstract The physiological determinants of high-intensity exercise tolerance are important for both elite human performance and morbidity, mortality disease in clinical settings. asymptote the hyperbolic relation between external power time to task failure, critical power, represents threshold intensity above which systemic intramuscular metabolic homeostasis can no longer be maintained. After ~ 60 years research into phenomenon a clear understanding its has emerged. purpose present review is critically examine this contemporary evidence order explain underpinnings power. Evidence demonstrating that alterations convective diffusive oxygen delivery impact upon first addressed. Subsequently, considered shows rates muscle utilisation, inferred via kinetics pulmonary consumption, influence data reveal picture flux along every step transport utilisation pathways It also influenced by motor unit recruitment patterns. On basis, it proposed act concert with determine intracellular milieu state fatigue within myocytes. This interacts exercising mass patterns ultimately

Language: Английский

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Cardiorespiratory Fitness and Performance Adaptations to High-Intensity Interval Training: Are There Differences Between Men and Women? A Systematic Review with Meta-Analyses

Sports Medicine, Journal Year: 2023, Volume and Issue: 54(1), P. 127 - 167

Published: Sept. 7, 2023

Abstract Background It is important to consider biological sex as a variable that might influence exercise adaptation in order optimize prescription for men and women. Objective The aim of this study was quantify the impact on maximal oxygen uptake ( $$\dot{V}$$ V˙ O 2max ) performance outcomes after high-intensity interval training (HIIT). Methods A systematic search review conducted by two independent reviewers up 8 September 2022 using MEDLINE, SPORTDiscus, Sports Medicine & Education Index ProQuest. Trials including healthy adults were included if they presented data or compared male female response HIIT. Performance measures concurrently measured physiological adaptations. Where appropriate, random-effects, pre-post meta-analysis undertaken. Data sub-grouped women, baseline level, mean age, intervention type, length. Heterogeneity assessed Chi 2 , Cochran’s Q Higgins I sensitivity analyses, where required. Study quality Newcastle–Ottawa Scale publication bias through visual inspection funnel plots. Results Thirty-three references from 28 trials n = 965; 462 women 503 men). Meta-analyses 19 studies eight peak power output testing (PPO), five threshold (power AT ). revealed similar increases g 0.57; 95% CI 0.44–0.69) 0.42–0.72), 0.38; 0.13–0.64) 0.11–0.64). Raw differences change Δ 0.32 L·min −1 3.50 mL·kg ·min men, versus 0.20 3.34 No significant present primary analysis any outcome. After sub-grouping, PPO effect size higher well-trained 0.37) with 0.17), interventions duration 4 weeks less had significantly smaller sizes those longer than p < 0.001). Unweighted percentage PPO, across 11.16 ± 7.39%, 5.99%, 8.07 6.55% 10.90 5.75%, 8.22 5.09%, 7.09 7.17% respectively. Significant heterogeneity both range: 62.06–78.80%). Sub-grouping status length decreased most groups. qualitative synthesis other indicated improvements fitness some evidence suggesting mechanisms adaptation. Limitations Risk Bias Publication unlikely have influenced results but could benefitted additional strengthen results. overlap age categories limits accuracy sub-grouping age. Conclusions Findings no sex-specific outcomes. Baseline accounted variability PROSPERO registration number: CRD42021272615.

Language: Английский

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The influence of skeletal muscle mitochondria and sex on critical torque and performance fatiguability in humans

The Journal of Physiology, Journal Year: 2023, Volume and Issue: 601(23), P. 5295 - 5316

Published: Oct. 30, 2023

Critical torque (CT) represents the highest oxidative steady state for intermittent knee extensor exercise, but extent to which it is influenced by skeletal muscle mitochondria and sex unclear. Vastus lateralis biopsy samples were collected from 12 females males -matched relative maximal oxygen uptake normalized fat-free mass (FFM) (F: 57.3 (7.5) ml (kg FFM)-1 min-1 ; M: 56.8 (7.6) P = 0.856) - prior CT determination performance fatiguability trials. Males had a lower proportion of myosin heavy chain (MHC) I isoform (40.6 (18.4)%) compared (59.5 (18.9)%; 0.021), MHC IIa IIx distributions protein markers mitochondrial content not different between sexes (P > 0.05). When maximum voluntary contraction (MVC), 42.9 (8.3)%; 37.9 (9.0)%; 0.172) curvature constant, W' 26.6 (11.0) N m s (N m)-1 26.4 (6.5) 0.962) significantly sexes. All biomarkers content, as well isoform, positively correlated with (0.48 < r 0.70; 0.05), (r 0.57; 0.007). Indices MVC- CT-controlled trials Greater abundance was associated attenuated declines in potentiated twitch exercise at 60% MVC 0.05); however, influence on reduced when prescribed CT. Whether these findings translate whole-body requires additional research. KEY POINTS: The quadriceps critical intensity an attainable, its relationship unknown. Matching facilitates investigations differences physiology, studies that have during ensured equal aerobic fitness Skeletal fatigue resistance performed torque. Differences torque, statistically significant. Our results suggest may contribute influencing exercise.

Language: Английский

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Impact of training modes on fitness and body composition in women with obesity: A systematic review and meta‐analysis

Obesity, Journal Year: 2022, Volume and Issue: 30(2), P. 300 - 319

Published: Jan. 27, 2022

Abstract Objective This study aimed to assess the effectiveness of different exercise modalities and determine optimal prescription for improving cardiorespiratory fitness, body composition, metabolic health women with obesity. Methods A systematic review randomized controlled trials (RCTs) published between January 1988 October 2020 was conducted. The RCTs were screened using following inclusion criteria: 1) participants: aged 18 65 years BMI > 30 kg/m 2 without comorbidities; 2) intervention: exercise; 3) comparison: non‐intervention control; 4) outcomes measures: fitness (maximal oxygen consumption), composition (i.e., weight, percentage fat), and/or measures blood pressure, cholesterol). Results total 20 a 2,062 participants included. Although results showed that any form more effective than control, improvements in modest. Aerobic (vigorous moderate intensity) appeared most promising whereas low‐load resistance training resulted largest fatness. Conclusions In living obesity, aerobic consistently composition. both combined interventions appear promising, research is needed evaluate their efficacy an this population.

Language: Английский

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Sex-specific tuning of modular muscle activation patterns for locomotion in young and older adults

PLoS ONE, Journal Year: 2022, Volume and Issue: 17(6), P. e0269417 - e0269417

Published: June 3, 2022

There is increasing evidence that including sex as a biological variable of crucial importance to promote rigorous, repeatable and reproducible science. In spite this, the body literature accounts for participants in human locomotion studies small often produces controversial results. Here, we investigated modular organization muscle activation patterns using concept synergies with double purpose: i) uncover possible sex-specific characteristics motor control ii) assess whether these are maintained older age. We recorded electromyographic activities from 13 ipsilateral muscles lower limb young adults both sexes walking (young old) running (young) on treadmill. The data set obtained 215 was elaborated through non-negative matrix factorization extract time-independent (i.e., modules) time-dependent primitives) coefficients synergies. found sparse modulations control. Motor modules showed different contribution hip extensors, knee extensors foot dorsiflexors various primitives were wider lasted longer) males propulsion synergy (but only not adults) weight acceptance running. Moreover, complexity similar younger sexes, but females compared males. essence, our results revealed existence defined differences way humans entirely

Language: Английский

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No sex differences in oxygen uptake or extraction kinetics in the moderate or heavy exercise intensity domains

Journal of Applied Physiology, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 11, 2024

The integrative response to exercise differs between sexes, with oxidative energy contribution purported as a potential mechanism. present study investigated whether this difference was evident in the kinetics of oxygen uptake (V̇o

Language: Английский

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Effects of the Menstrual Cycle and Hormonal Contraceptive Use on Metabolic Outcomes, Strength Performance, and Recovery: A Narrative Review

Metabolites, Journal Year: 2024, Volume and Issue: 14(7), P. 347 - 347

Published: June 21, 2024

The effects of female sex hormones on optimal performance have been increasingly recognized as an important consideration in exercise and sport science research. This narrative review explores the findings studies evaluating menstrual cycle phase eumenorrheic women use hormonal contraception (oral contraceptives intrauterine devices) metabolism, muscular strength, recovery active females. Ovarian are known to influence metabolism because estrogen is a master regulator bioenergetics. Importantly, may impact protein synthesis, impacting skeletal muscle quality strength. Studies investigating strength report equivocal between follicular luteal with no differences compared oral contraceptive users. examining measures (using biomarkers, blood lactate, flow) do not clear or consistent recovery. Overall, current literature be limited by evaluation only one group means for statistical significance. Hence, optimize training females, regardless use, there need future research quantify intra-individual phases

Language: Английский

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The Effect of Duration on Performance and Perceived Fatigability During Acute High‐Intensity Interval Exercise in Young, Healthy Males and Females

Scandinavian Journal of Medicine and Science in Sports, Journal Year: 2024, Volume and Issue: 34(7)

Published: July 1, 2024

ABSTRACT Few studies have explored the kinetics of performance and perceived fatigability during high‐intensity interval training, despite its popularity. We aimed to characterize recovery an 8 × 4‐min HIIT protocol, hypothesizing that most muscle function impairment would occur initial four intervals. Fifteen healthy males females (mean ± standard deviation; age = 26 5 years, V̇ O 2 max 46.8 6.1 mL·kg −1 ·min ) completed eight, intervals at 105% critical power with 3 min rest. Maximal voluntary knee extension contractions (MVCs) coupled electrical nerve stimulation were performed baseline after first, fourth, eighth MVC, potentiated twitch force (Pt), Db10:100 ratio all declined throughout ( p < 0.05). MVC sharply 1 (−15 9% relative baseline; 0.05) had only further (−26 11%; 0.05), but not 4 (−19 13%; > Pt also (Pt: −18 13%, Db10:100: −14 20%; −35 19%, −30 −41 19%; −32 18%; Voluntary activation did significantly change across protocol Evoked was blunted as more completed: 1, recovered by 7 11% compared −6 7% Ratings effort, fatigue, leg pain rose session 0.05 for each) greater (effort fatigue) Otherwise, exhibited similar kinetics, contractile declines in response additional

Language: Английский

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