Timing is everything: complex (a)synchrony of heart–muscle interactions during exercise

The Journal of Physiology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Exercise requires physiological adjustments to defend regulatory variables. Oxygen delivery is augmented support metabolic rate, inactive tissues vasoconstrict maintain blood pressure, the vasculature dilates convective heat transfer, cardiovascular reflexes perfusion and arterial etc. At whole-body level, result sustainment of power output until demand outpaces oxygen supply. While numerous are involved during exercise, it fair say that cardiorespiratory musculoskeletal systems dominate: former as contractile units driving locomotion latter transport required for energy provision. Thus, would make sense there a link between muscle cardiac activity, such they exhibit temporal coordination achieve efficient movement. During concentric contractions intramuscular pressure transiently impedes flow, followed by hyperaemia relaxation due an increased gradient across vasculature. Theoretically, coupling contraction with rhythms (cardio-locomotor coupling) dissociates peaks occurring at same time, promoting greater flow in decreasing afterload. Natural entrainment heart rate (HR) cadence occurs running (Kirby et al., 1989), coaching foot strikes occur diastole haemodynamically beneficial. However, previous investigations used surrogates activity (foot strike) measured only snapshots exercise responses (i.e. stroke volume specified time points). This broader limitation physiology general where, historical inertia methodological limitations, our data sometimes fail capture human body non-linear dynamic network relying on isolated/static measures explain complex physiology. When viewed adaptive system, outcomes (e.g. aerobic performance) cannot be solely determined one component or mitochondrial content) (Balague 2020). Even higher-level isolated variables economy, which represents several individual characteristics (biomechanics, tendon properties, bioenergetics), not sufficient itself performance. Complex networks city) made up nodes/components (businesses, homes, people) interact through various connections/linkages (transportation systems, relationships). The collective behaviour city (its economy resources information) but how all nodes interact. Seminal work Bashan al. (2012) introduced field Network Physiology organism exemplifies integration multiple outcome. authors showed substantial connectivity within brain periphery sleep, importantly, these connections facilitated emergence basic conditions (transition from deep light sleep) (Bashan 2012). Globally, focuses hierarchically structured organ adapt real achieve, transition between, different states sleep/wake, rest/exercise, health/disease), continuous streams areas interest. In this issue Journal Physiology, Garcia-Retortillo Ivanov studied heart–muscle exhaustive framework (Garcia-Retortillo & Ch Ivanov, 2024). Their study comprehensively analysed cardiomuscular network, its function relationship fatigue. Two important points differentiating were use EMG (compared cadence) coupled ECG cross-correlation analyses instantaneous signals visualize evolution over time. protocol was relatively simple: participants performed two sets bodyweight squats tempo (3 s eccentric/3 concentric) exhaustion, separated 5 min (acute residual fatigue). Electrodes placed both quadriceps erector spinae. Decomposition spectral allowed grouping into 10 frequency bands, ranging 10–29.5 Hz (F1) 205–224.5 (F10), rationale correspondence fibre types (type I: F1–F2; type IIa: F3–F7; IIx: F8–F10). Cardio-muscle synchrony cross-correlations HR (ECG) bands (negative correlation = −1, positive 1), then strength each pair, resulting >17,000 links given their sample size, bouts number locations. Essentially, degree observed (higher better coupling). variability relation further assessed analysing first last third bout. essence, (analysed short large scales) allow identification sustainability fatigue (synchrony asynchrony). Both periodized 6 windows corresponding tempo, virtually overlapping another half than Muscle band amplitude progressively fatigue, reflecting need higher threshold motor unit recruitment meet physical demand. There also decline respiratory sinus arrhythmia amplitude, probably pointing reflex-driven ventilatory demands accumulating As result, declined sympathetic activity. Remarkably, regardless throughout consistently occurred 0.15 Hz, aligning (1 squat/6 0.15). always retained periodicity regard prescribed fell out sync other when set in. general, strengths far stronger lower indicating may more fine-tuned oxidative accumulated, degraded low-frequency type-specific differences lost. Overall reduced ∼45 (quadriceps) 60% (low back) compared non-fatigued state. bout 2 (residual fatigue), much F6–F10 range IIa–IIx), exemplifying lack resistance fibres. A frequent earlier onset negative (link strength) values prevalent versus 1 2. subject, F10 almost fully onwards (fig. 6A paper). Accumulation probability (positive linkages 20% anti-correlations ∼40%; worsened probabilities. Collectively, using advanced analytical methods, able precisely quantify Further, demonstrate (1) muscles types, (2) decreased relates parasympathetic withdrawal neuromuscular importantly (3) changes (on scale few seconds) fresh fatigued state, bouts. Reductionist studies have helped mechanistically training-induced quality control). involves layers interacting contributing molecular facet larger organization. It fact 'exercise pill' remains elusive – truly integrative phenomenon represented replicated focusing component. advances biology -omics technology been profound, definition methods confine single restrained level analysis, ignoring overlooking complexity observations Molecular course upside stall progress bigger translational questions (Joyner, 2011). Placing onus complements avenue accelerate understanding what reductionism can provide. unique results (2024) open door wide new research complement seminal work, extending cardio-locomotor concept. Mortensen (2013) improving capacity alone favourably influences improves intolerance. Inherent findings role skeletal afferents autonomic control, where heightened metaboreflex sensitivity precipitates dyspnoea adrenergic activation, modifiable training (Aimo 2021). Postural orthostatic challenges influence outflow via baroreflex. Recently, crude concept, ratio internal (%HRmax) external workload (% critical speed, CS) (Smyth 2022), effectively applied analysis >80,000 marathon runners. Low high 'decouplers' ran faster 0.3 m/s average, experienced decoupling ∼14 km later (33 vs. 19 km) fraction CS (88 82%). integrator inputs regulating resolution defining deviation homeostasis onset/presence progressive II fibres proposed mediator V ̇ O ${{\dot{V}}_{{{{\mathrm{O}}}_{\mathrm{2}}}}}$ slow (and thus Indeed, temporally aligned loss efficiency suggesting I finding quite emphasizing rather per se crucial shedding feature intensity–duration relationship. Fibre-specific teleological underpinning Homo sapiens slow-twitch endurance Many sport-related phenomena will resolved increasing capability measure biological molecules incorporating laws regulation (Bartsch 2015). Prime examples include mechanistic basis still debated (Westerblad, 2016), overtraining syndrome. cases bottom-up model (molecules transmitting information 'up' affect whole body) has often assumed. Fatigue (molecules, cells organs) psychological (motivation stress) factors develops disparate scales. Overtraining disorder non-functional current biomarkers hormones variability) inadequate detection. Quantifying diverse superior strategy tests already demonstrated detecting dysfunction 2020; Da Silva 2023). Accepting multifactorial origin states, measurement accuracy achieved shifting microscopic mesoscopic approach 2022). Through identified operate organizational integrate levels directions causal interactions (bottom-up, top-down, horizontal, circular causality, etc.) makes integrated phenomena. Importantly, effect cellularly constrain fluctuations. For instance, 2024) strengthened perfusion, context relevant know whether caused fluctuations nitric oxide prostaglandins (known vasodilators). Hence major question tackle future re-compose previously decomposed mechanisms opens ideas involving trainability, application prescription, modification disease extreme environments, recovery asynchrony synchrony, transitions alignment parameters. likely connectivity, diversity 'resilience' 'durability' athletes 2022) extension population, making metrics relevant. growing suggests nearly health lead us novel unattainable traditional methods. views, opinions and/or contained article private view author construed official United States Department Army position, decision, unless so designated documentation. Approved public release, distribution unlimited. Citations commercial organizations trade names report do constitute U.S. endorsement approval products services organizations. Please note: publisher responsible content functionality any supporting supplied authors. Any queries (other missing should directed article. None declared. S.L.: Conception design drafting revising critically intellectual content, final version published, agreement accountable aspects work. None.

Language: Английский

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Detection of respiratory frequency rhythm in human alpha phase shifts: topographic distributions in wake and drowsy states

Frontiers in Physiology, Journal Year: 2025, Volume and Issue: 15

Published: Jan. 6, 2025

The relationship between brain activity and respiration is recently attracting increasing attention, despite being studied for a long time. Respiratory modulation was evidenced in both single-cell field potentials. Among EEG intracranial measurements, the effect of prevailingly on amplitude/power all frequency bands. Since phases oscillations received less we applied our previously published carrier (CF) mathematical model human alpha group 10 young healthy participants wake drowsy states, using 14-channel average reference montage. approach allows more precise calculation CF phase shifts (CFPS) than any individual Fourier component, by 2-s moving window, validated new method studied, first time, temporal waveforms CFPS(t) their oscillatory content through FFT (CFPS(t)). Although not appearing equally channel pairs every subject, clear peak respiratory region, 0.21-0.26 Hz, observed (max at 0.22 Hz). When five with most prominent averaged amplitudes Hz were plotted topographic distributions changed significantly-from longitudinal, connecting frontal posterior channels state to topographically split two separate regions-frontal state. In addition, state, 0.22-Hz decreased pairs, while statistically significant reduction obtained 20/91 (22%) pairs. These results potentially evidence, shifts, as well impact wakeful consciousness oscillations.

Language: Английский

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Diabetes alters cardiorespiratory dynamics: insights from short-term recurrence quantification analysis of pulse-respiration quotient

Frontiers in Physiology, Journal Year: 2025, Volume and Issue: 16

Published: April 25, 2025

The Pulse-Respiration Quotient (PRQ) is considered a powerful tool for assessing dynamic interactions between cardiac and respiratory rhythms. Type 2 diabetes mellitus (T2DM) disrupts autonomic control, potentially compromising the complexity adaptability of cardiorespiratory dynamics. In this cross-sectional, exploratory study, we investigated whether T2DM alters dynamics by analyzing short-term PRQ signals using conventional linear indices Recurrence Quantification Analysis (RQA). Thirty-eight participants (20 18 controls) completed four standardized tasks-supine rest, orthostatic challenge, paced breathing, Valsalva maneuver-while electrocardiographic were continuously recorded. From these signals, R-to-R peak interval (RRI) breath-to-breath (BB) time series derived, allowing us to compute as ratio instantaneous heart rate breathing rate. Linear RQA metrics then calculated enabling comparisons groups (T2DM vs. control) across tasks. Additionally, entropy-based mutual information (MI) RRI BB was assessed quantitative measure coupling. exhibited higher recurrence rates prolonged first type in series, especially during suggesting more rigid less adaptive control mechanism. Although showed changes some stage-dependent responses, they adept than at discerning subtle differences groups. Furthermore, complementary coupling assessment MI revealed distinct compensatory patterns respiration Valsalva. These findings indicate potential dysautonomia or partial dysregulation individuals with T2DM, reflected altered reduced adaptability.

Language: Английский

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Cardiorespiratory dynamics during respiratory maneuver in athletes

Frontiers in Network Physiology, Journal Year: 2023, Volume and Issue: 3

Published: Oct. 30, 2023

Introduction: The modern practice of sports medicine and medical rehabilitation requires the search for subtle criteria development conditions recovery body after diseases, which would have a prognostic value prevention negative effects training tools, also testify to course mechanisms counteracting pathogenetic processes in body. purpose this study was determine informative directions cardiorespiratory system parameters dynamics during performing maneuver with change breathing rate, may indicate functional state violation. Methods: results 183 healthy men aged 21.2 ± 2.3 years who regularly engaged various were analyzed. procedure studying included conducting combined measurements indicators activity respiratory cardiovascular systems sitting position using spiroarteriocardiograph device. duration 6 min involved sequential registration three rate (spontaneous breathing, at 0.1 Hz 0.25 Hz). Results: Performing comparison spontaneous leads multidirectional significant changes heart variability indicators-TP (ms2), LF LFHF (ms2/ms2); blood pressure indicators-TPDBP (mmHg2), LFSBP LFDBP HFSBP (mmHg2); volume respiration - LFR, (L×min-1)2; HFR, LFHFR, (L×min-1)2/(L×min-1)2; arterial baroreflex sensitivity BRLF (ms×mmHg-1), BRHF (ms×mmHg-1). Differences systemic hemodynamics synchronization informative. Conclusion: According study, it is shown that there are parameters, analysis increments made possible dynamics, their absolute values limits regarding occurrence interactions dysregulation.

Language: Английский

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Unanticipated evolution of cardio-respiratory interactions with cognitive load during a Go-NoGo shooting task in virtual reality

Computers in Biology and Medicine, Journal Year: 2024, Volume and Issue: 182, P. 109109 - 109109

Published: Sept. 10, 2024

Language: Английский

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Cardiorespiratory synchronization under the influence of strength endurance training

Physical rehabilitation and recreational health technologies, Journal Year: 2024, Volume and Issue: 9(1), P. 25 - 35

Published: Jan. 30, 2024

Purpose: to determine changes in the parameters of cardiorespiratory relationships during maneuver with a change breathing rate after 4-month cycle training aimed at development strength endurance. Material & Methods: results spiroarteriocardiorhythmographic study 22 healthy men aged 20.7±2.3 years, who for 4 months 2 times week 90 minutes, were analyzed (a total 30 classes held) engaged The indicators heart (min–1), respiratory cardiac output (dm3×min–1), minute lung ventilation (L×min–1) and their derivatives – Hildebrandt index (HR/RR) volume synchronization (CO/V), which obtained spontaneous respiration controlled 0.1 Hz 0.25 Hz. Results: it was shown that endurance led probable decrease from 71.4 (63.9; 77.5) 64.3 (60.8; 68.3), p=0.002, 14.1 (12, 7; 16.8) 13.8 (10.7; 15.3), p= 0.020 8.19 (6.24; 8.86) 6.40 (3.73; 7.74) ), p=0.004 breathing, as well significant increase volumetric index. (dm3×L–1) 0.597 (0.490; 0.832) 0.725 (0.564; 1.148), p=0.008, 0.327 (0.382; 0.529) 0.532 (0.441; 0.723), p=0.012 0,245 (0,339; 0,455) 0,481 (0,373; 0,616), р=0,003 against background 0,1 11.14 (10.43; 12.49) 10.18 (9.54; 11.00), p=0.001, 5.33 (4.68; 5.85) 4.46 (4.13; 4, 78), p=0.000. Conclusions: an economization cardiovascular systems function response sympathoadrenal activation hyperventilation.

Language: Английский

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A study on the immediate effects of enhanced external counterpulsation on physiological coupling

Frontiers in Neuroscience, Journal Year: 2023, Volume and Issue: 17

Published: June 7, 2023

Enhanced external counterpulsation (EECP) is a non-invasive assisted circulation technique for its clinical application in the rehabilitation and management of ischemic cardiovascular cerebrovascular diseases, which has complex physiological hemodynamic effects. However, effects EECP on coupling systems are still unclear. We aimed to investigate immediate between integrated such as cardiorespiratory systems.Based random sham-controlled design, simultaneous electrocardiography, photoplethysmography, bio-electrical impedance, continuous data were recorded before, during after two consecutive 30 min 41 healthy adults. Physiological strength quantified by phase synchronization indexes (PSI), measurements heart rate variability indices 22 subjects (female/male: 10/12; age: 22.6 ± 2.1 years) receiving active calculated compared with those 19 sham control 7/12; 23.6 2.5 years).Immediately interventions, respiratory PSIRES-PTT (0.34 0.14 vs. 0.49 0.17, P = 0.002), cardiac PSIIBI-PTT (0.41 0.52 0.16, 0.006) total PSItotal (1.21 0.35 1.57 0.49, 0.005) group significantly lower than before intervention, while did not change (P > 0.05).Our study provides evidence that PSI altered intervention. speculate reduced induced may be marker disturbed coupling. This new method exploring mechanism action help further optimize technique.

Language: Английский

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Machine Learning Classification of Pediatric Health Status Based on Cardiorespiratory Signals with Causal and Information Domain Features Applied—An Exploratory Study

Journal of Clinical Medicine, Journal Year: 2024, Volume and Issue: 13(23), P. 7353 - 7353

Published: Dec. 2, 2024

This study aimed to evaluate the accuracy of machine learning (ML) techniques in classifying pediatric individuals-cardiological patients, healthy participants, and athletes-based on cardiorespiratory features from short-term static measurements. It also examined impact coupling (CRC)-related (from causal information domains) modeling identify a preferred feature set that could be further explored for specialized tasks, such as monitoring training progress or diagnosing health conditions.

Language: Английский

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A framework based on the information domain to measure coupling changes in electrophysiological signals

Biomedical Physics & Engineering Express, Journal Year: 2023, Volume and Issue: 9(5), P. 055022 - 055022

Published: Aug. 1, 2023

Objectives.In this paper, the features of physiological signals healthy dataset are extracted using linear and non-linear techniques, a comparison has been made on young old subjects to study aging gender-related changes in contribution Heart Rate (HR), Blood Pressure (BP), Respiration (RESP).Methods. To quantify coupling cardiovascular, cardiorespiratory, vasculorespiratory complexity, an information domain approach based compensated transfer entropy (cTE) is proposed.Result. The results show that there substantial decrease flow from BP tro time interval between successive R-peaks (RR) RR BP. There also significant RESP but no change RESP.Conclusion. We have done analysis datasets subjects. As already existed techniques lacks studying complex behaviours electrophysiological so overcome these limitations, we proposed (cTE). conducted investigation determine degree which recordings RESP, BP, HR can be utilized predict other parameters. Specifically, examined relationship variables assessed their consistency across different age groups genders. By analyzing data, aimed gain insights into interdependencies predictive potential measures relation each other.

Language: Английский

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