Cardiac Autonomic Modulation in Response to Muscle Fatigue and Sex Differences During Consecutive Competition Periods in Young Swimmers: A Longitudinal Study

Objective: To study the differences in cardiac autonomic modulation in response to muscle fatigue caused by high-intensity exercise during two consecutive competition periods in young swimmers.Methods: Twenty-six competitive swimmers, selected by their training volume, were separated in two groups, females (n = 12 [46%], age: 13.5 ± 1.4 years) and males (n = 14 [54%], age: 13.9 ± 1.7 years), aged between 10 and 16 years, were evaluated five times as follow: (i) 21 days before the first competition (t-0); (ii) two days before (t-1; t-3); and (iii) two days after (t-2; t-4) of the first and second competitions. Morphological measurements (body mass, percentage of total body fat and height), blood pressure, power, and resting heart rate variability (RR with Polar band) were recorded before and after Wingate test at each time.Results: Body fat was higher in females compared to males. However, no differences were found in other morphological parameters. An intra-subject analysis grouped by sex in cardiovascular parameters shows longitudinal variations in systolic pressure and mean pressure among females. Additionally, females depicted higher, very low frequency (VLF, which is intrinsically generated by the heart and strongly associated with emotional stress) after physical fatigue compared to males at t-1. Further, before the competition, the high frequency (HF) component of HRV (parasympathetic drive) was higher in males than females at t-0 and t-4.Conclusion: Our data revealed that males displayed greater parasympathetic reactivity after an anaerobic muscle fatigue test during their competition periods. Contrarily, females had a less cardiac autonomic modulation when comparing the pre-post Wingate test after two consecutive competition periods.

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Reversal of muscle fatigue during 16 h of heavy intermittent cycle exercise

Journal of Applied Physiology ◽

10.1152/japplphysiol.00565.2004 ◽

2004 ◽

Vol 97 (6) ◽

pp. 2166-2175 ◽

Cited By ~ 11

Author(s):

H. J. Green ◽

T. A. Duhamel ◽

S. Ferth ◽

G. P. Holloway ◽

M. M. Thomas ◽

...

Keyword(s):

Oxygen Consumption ◽

Muscle Fatigue ◽

Intermittent Exercise ◽

Low Frequency ◽

Quadriceps Muscle ◽

Stimulation Frequency ◽

Peak Oxygen Consumption ◽

Force Frequency ◽

Reduction In Force ◽

Before And After

This study examined the effects of extended sessions of heavy intermittent exercise on quadriceps muscle fatigue and weakness. Twelve untrained volunteers (10 men and 2 women), with a peak oxygen consumption of 44.3 ± 2.3 ml·kg−1·min−1, exercised at ∼91% peak oxygen consumption for 6 min once per hour for 16 h. Muscle isometric properties assessed before and after selected repetitions (R1, R2, R4, R7, R12, and R15) were used to quantitate fatigue (before vs. after repetitions) and weakness (before vs. before repetitions). Muscle fatigue at R1 was indicated by reductions ( P < 0.05) in peak twitch force (135 ± 13 vs. 106 ± 11 N) and by a reduction ( P < 0.05) in the force-frequency response, which ranged between ∼53% at 10 Hz (113 ± 12 vs. 52.6 ± 7.4 N) and ∼17% at 50 Hz (324 ± 27 vs. 270 ± 30 N). No recovery of force, regardless of stimulation frequency, was observed during the 54 min between R1 and R2. At R2 and for all subsequent repetitions, no reduction in force, regardless of stimulation frequency, was generally found after the exercise. The only exception was for R2, where, at 20 Hz, force was reduced ( P < 0.05) by 18%. At R15, force before repetitions for high frequencies (i.e., 100 Hz) returned to R1 (333 ± 29 vs. 324 ± 27 N), whereas force at low frequency (i.e., 10 Hz) was only partially ( P < 0.05) recovered (113 ± 12 vs. 70 ± 6.6 N). It is concluded that multiple sessions of heavy exercise can reverse the fatigue noted early and reduce or eliminate weakness depending on the frequency of stimulation.

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Abstract P200: The Circadian Pattern of Cardiac Autonomic Modulation and its Correlates in Adolescents- Penn State Child Cohort (PSCC) Study

Circulation ◽

10.1161/circ.129.suppl_1.p200 ◽

2014 ◽

Vol 129 (suppl_1) ◽

Author(s):

Sol M Rodriguez-Colon ◽

Fan He ◽

Edward O Bixler ◽

Julio Fernandez-Mendoza ◽

Susan Calhoun ◽

...

Keyword(s):

Heart Rate ◽

Low Frequency ◽

Population Based ◽

Autonomic Modulation ◽

Circadian Pattern ◽

Late Afternoon ◽

Cardiac Autonomic Modulation ◽

Penn State ◽

State Child ◽

The Mean

Objective: To examine the circadian pattern of cardiac autonomic modulation (CAM) and its correlates in a population-based sample of adolescents. Methods: We used the data from 400 adolescents who completed the follow up exam in the PSCC study. CAM was assessed by heart rate variability (HRV) analysis of beat-to-beat normal R-R intervals from a 24-hour (7:00 PM to 7:00 PM) ECG, on a 30-minute basis (48 segments/person). The HRV indices included frequency domain: [high and low frequency powers (HF, LF), and LF/HF ratio] and time domain: [standard deviation of normal RRs (SDNN), and the square root of the mean squared difference of successive normal RRs (RMSSD), and heart rate (HR)]. We used a cosine periodic model to estimate each participant’s circadian parameters: mean (M), amplitude (Â), and crescent time (θ). We then used mixed-effects models to calculate group level circadian pattern as the overall M, Â of the oscillation, and θ of the highest oscillation. Results: The mean age was 16.9 yrs (SD=2.2), with 54% male and 77% white. The mean BMI percentile is 61, with 16% were obese (BMI percentile ≥ 95). Overall, the parasympathetic modulation gradually increases from late afternoon throughout the evening, and reaches the peak amplitude around 3:00 AM, at which it gradually decrease throughout most of the daytime until late afternoon. The age, sex and race showed varying differences on the CAM circadian parameters. In contrast, obesity in adolescents had adverse effects on all three circadian parameters. Using HF (a reliable index of parasympathetic modulation) as an example, the circadian pattern of the entire sample, and stratified by obesity are shown in Figure 1. Conclusion: Circadian pattern of CAM can be quantified by three cosine parameters (M, Â, and θ). Obesity in adolescents is already associated with a CAM profile indicative of sympathetic overflow and reduced parasympathetic modulation, at all levels of the CAM circadian rhythm.

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Females and males do not differ for fatigability, muscle damage and magnitude of the repeated bout effect following maximal eccentric contractions

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0516 ◽

2020 ◽

Author(s):

Christina D. Bruce ◽

Luca Ruggiero ◽

Gabriel U. Dix ◽

Paul D. Cotton ◽

Chris J McNeil

Keyword(s):

Muscle Fatigue ◽

Muscle Damage ◽

Low Frequency ◽

Calcium Handling ◽

High Frequency Stimulation ◽

Repeated Bout Effect ◽

Indirect Measure ◽

Force Depression ◽

Before And After ◽

Repeated Bout

Unaccustomed eccentric (ECC) exercise induces muscle fatigue as well as damage and initiates a protective response to minimize impairments from a subsequent bout (i.e., repeated bout effect; RBE). It is uncertain if the sexes differ for neuromuscular responses to ECC exercise and the ensuing RBE. Twenty-six young adults (13 females) performed two bouts (four weeks apart) of 200 ECC maximal voluntary contractions (MVCs) of the dorsiflexors. Isometric (ISO) MVC torque and the ratio of ISO torque in response to low- vs. high-frequency stimulation (10:100Hz) were compared before and after (2-10min and 2, 4, and 7d) exercise. The decline in ECC and ISO MVC torque, and the 10:100Hz ratio following bout one did not differ between sexes (P > 0.05), with reductions from baseline of 31.5 ± 12.3, 24.1 ± 15.4, and 51.3 ± 12.2%, respectively. After bout two, the 10:100Hz ratio declined less (45.0 ± 12.4% from baseline) and ISO MVC torque recovered sooner compared to bout one but no differences between sexes were evident for the magnitude of the RBE (P > 0.05). These data suggest that fatigability with ECC exercise does not differ for the sexes and adaptations that mitigate impairments to calcium handling are independent of sex. NOVELTY BULLETS: • One bout of 200 maximal eccentric dorsiflexor contractions caused equivalent muscle fatigue and damage for females and males • The repeated bout effect observed after a second bout four weeks later also had no sex-related differences • Prolonged low-frequency force depression is promoted as an indirect measure of muscle damage in humans

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Twelve Pilates sessions improve muscle function but not cardiac autonomic modulation of sedentary patients with low-back pain.

Manual Therapy Posturology & Rehabilitation Journal ◽

10.17784/mtprehabjournal.2020.18.790 ◽

2020 ◽

Vol 18 ◽

pp. 1-6

Author(s):

Daniel Iwai Sakabe ◽

Fabiana Forti Sakabe ◽

Ariane Cristina Dias Souza ◽

Alline Pereira Guerreiro

Keyword(s):

Low Back Pain ◽

Back Pain ◽

Functional Capacity ◽

Training Evaluation ◽

Lower Limbs ◽

Autonomic Modulation ◽

Low Back ◽

Trunk Flexion ◽

Cardiac Autonomic Modulation ◽

Before And After

Introduction: Physical inactivity is a major risk factor for various pathological conditions in different organic systems, increasing the incidence of musculoskeletal disorders such as low-back pain, as well as the risk for cardiovascular disease. The aim of this study was to evaluate the effect of 12 Pilates sessions on muscle parameters, functional capacity and cardiac autonomic modulation. Methods: 10 volunteers with chronic low-back pain (25.1±5.1 years) underwent 4 assessments before and after training: hamstrings flexibility through photogrammetry; abdominal resistance, through the one minute trunk flexion test; functional capacity through the Roland Morris questionnaire; cardiac autonomic modulation by the RMSSD index of R-R intervals. Mat Pilates training program lasted 12 sessions, each one lasting an hour. Paired student t test, with the level of significance set at 5%, was used to compare data before and after training. Results: Significant improvements (p<0.05) were found on flexibility (58.7±8.2 to 84.1±10.3 degrees on right lower limbs and 57.2±9.1 to 78.5±11.9 on left lower limbs), abdominal resistance (28.3±17.6 to 33.6±16.0 repetitions) and functional capacity (6.2±2.8 to 3.3±1 0 points). Heart rate variability showed no significant change (p = 0.09) after training (RMSSD 37.5±15.0 in pre-training evaluation and 39.0±15.0 in post-training evaluation). Conclusions: We can conclude that the proposed Pilates program was effective in improving muscle and functional parameters, but did not change cardiac autonomic modulation.

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Effect of exercise-heat acclimation on cardiac autonomic modulation in Type 2 Diabetes: a pilot study

Applied Physiology Nutrition and Metabolism ◽

10.1139/apnm-2020-0785 ◽

2020 ◽

Author(s):

Michael J. Macartney ◽

Sean R. Notley ◽

Christophe Herry ◽

Ronald J Sigal ◽

Pierre Boulay ◽

...

Keyword(s):

Type 2 Diabetes ◽

Heart Rate ◽

Heat Acclimation ◽

Cardiac Risk ◽

Autonomic Modulation ◽

Older Individuals ◽

Cardiac Autonomic Modulation ◽

Before And After ◽

Bullet Point

The effects of exercise-heat acclimation (HA), in individuals with type 2 diabetes (T2D), on heart rate variability (HRV) remains unclear. We assessed electrocardiogram recordings during exercise-heat stress, in middle-aged-to-older individuals (50-70 years) with (n=6) and without (n=8; CON) T2D, before and after 7-days exercise HA. Exercising heart rate was reduced (CON, -9 ±5 bpm; T2D, -14 ±9 bpm) yet HRV was unresponsive. Given the negative correlations between diminished HRV and cardiac risk, further research is warranted. <b>Novelty bullet point:</b> Our observations indicate that exercise-heat acclimation may not effectively attenuate the deviation toward reduced overall HRV and unfavourable cardiac autonomic modulation in individuals with T2D.

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Carbohydrate ingestion induces sex-specific cardiac vagal inhibition, but not vascular sympathetic modulation, in healthy older women

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00486.2015 ◽

2016 ◽

Vol 311 (1) ◽

pp. R49-R56 ◽

Cited By ~ 3

Author(s):

Lei Cao ◽

Stuart L. Graham ◽

Paul M. Pilowsky

Keyword(s):

Heart Rate ◽

Cardiovascular Risk ◽

Arterial Pressure ◽

Older Women ◽

Low Frequency ◽

Standing Position ◽

Autonomic Modulation ◽

Carbohydrate Ingestion ◽

Before And After ◽

Sequence Method

The role of vagal function in cardiovascular risk in older women remains unclear. Autonomic modulation following carbohydrate ingestion (CI) and postural stress (PS) were investigated in 14 healthy men and 21 age-matched postmenopausal women (age: 65.0 ± 2.1 vs. 64.1 ± 1.6 years), with normal and comparable insulin sensitivity. Continuous noninvasive finger arterial pressure and ECG were recorded in the lying and the standing positions before and after ingestion of a carbohydrate-rich meal (600 kcal, carbohydrate 78%, protein 13%, and fat 8%). Low-frequency (LF, 0.04–0.15 Hz) and high-frequency (HF, 0.15–0.4 Hz) components (ms2) of heart rate variability (HRV), low-frequency power (mmHg2) of systolic blood pressure variability (SBP LF power), and the sequence method for spontaneous baroreflex sensitivity (BRS, ms/mmHg) were used to quantify autonomic modulation. In response to CI and PS, mean arterial pressure maintained stable, and heart rate increased in women and men in the lying and standing positions. Following CI (60, 90, and 120 min postprandially) in the standing position, SBP LF power increased by 40% in men ( P = 0.02), with unchanged HRV parameters; in contrast, in women, HRV HF power halved ( P = 0.02), with unaltered SBP LF power. During PS before and after CI, similar magnitude of SBP LF power, HRV, and BRS changes was observed in men and women. In conclusion, CI induces sex-specific vascular sympathetic activation in healthy older men, and cardiac vagal inhibition in healthy older women; this CI-mediated efferent vagal inhibition may suggest differential cardiovascular risk factors in women, irrespective of insulin resistance, and impairment of autonomic control.

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Parasympathetic modulation during sleep time is reduced after maximal exercise, correlated with aerobic fitness in young women

Brazilian Journal of Kinanthropometry and Human Performance ◽

10.1590/1980-0037.2021v23e83295 ◽

2021 ◽

Vol 23 ◽

Author(s):

Gabriel Kolesny Tricot ◽

Jaqueline Alves Araújo ◽

Fabiula Isoton Novelli ◽

Guilherme Morais Puga ◽

Gisela Arsa ◽

...

Keyword(s):

Heart Rate ◽

Young Women ◽

Aerobic Fitness ◽

High Frequency ◽

Maximal Exercise ◽

Low Frequency ◽

Sleep Time ◽

Autonomic Modulation ◽

Cardiac Autonomic Modulation ◽

Holter Monitor

abstract It is known that cardiovascular risk is increased during exercise and recovery. Thus, it is necessary to assess all the risk associated with exercise to minimize the possibility of cardiovascular events. The aim of this study was to verify whether a maximal exercise alters ambulatory cardiac autonomic modulation in untrained women and whether aerobic fitness is correlated to cardiac autonomic modulation. Twelve women (25.35 ± 5.44 years) were outfitted with the Holter monitor on an experimental (after maximum exercise) and a control day to heart rate variability (HRV) evaluation. Maximal exercise increased 24 h heart rate (82 ± 14 vs 77 ± 11 bpm; p = 0.04) and during sleep time (72 ± 14 vs. 65 ± 9 bpm; p = 0.01), reduced parasympathetic modulation (HF – n.u. 49.96 ± 11.56 vs 42.10 ± 14.98; p = 0.04), and increased low-frequency/high-frequency ratio (2.88 ± 3.24 vs 1.31 ± 0.60; p = 0.03) during sleep time compared to the control day. Aerobic fitness was correlated positively with LF, HF, and HF (n.u.) indices (r = 0.61 to 0.73, p < 0.05) and correlated negatively with LF (n.u.) and LF/HF ratio (Rho = - 0.57 to - 0.69; p < 0.05). Maximal exercise alters parasympathetic modulation during sleep time in untrained women. Ambulatory cardiac autonomic modulation after exercise is related to aerobic fitness.

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Effects of bilateral lung transplantation on cardiac autonomic modulation and cardiorespiratory coupling: a prospective study

Respiratory Research ◽

10.1186/s12931-021-01752-6 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

E. Tobaldini ◽

G. D. Rodrigues ◽

G. Mantoan ◽

A. Monti ◽

G. Coti Zelati ◽

...

Keyword(s):

Prospective Study ◽

Lung Transplantation ◽

Total Power ◽

Autonomic Modulation ◽

Time Points ◽

Cardiac Autonomic Modulation ◽

Bilateral Lung Transplantation ◽

Before And After ◽

Bilateral Lung ◽

A Prospective Study

Abstract Background Although cardiac autonomic modulation has been studied in several respiratory diseases, the evidence is limited on lung transplantation, particularly on its acute and chronic effects. Thus, we aimed to evaluate cardiac autonomic modulation before and after bilateral lung transplantation (BLT) through a prospective study on patients enrolled while awaiting transplant. Methods Twenty-two patients on the waiting list for lung transplantation (11 women, age 33 [24–51] years) were enrolled in a prospective study at Ospedale Maggiore Policlinico Hospital in Milan, Italy. To evaluate cardiac autonomic modulation, ten minutes ECG and respiration were recorded at different time points before (T0) and 15 days (T1) and 6 months (T2) after bilateral lung transplantation. As to the analysis of cardiac autonomic modulation, heart rate variability (HRV) was assessed using spectral and symbolic analysis. Entropy-derived measures were used to evaluate complexity of cardiac autonomic modulation. Comparisons of autonomic indices at different time points were performed. Results BLT reduced HRV total power, HRV complexity and vagal modulation, while it increased sympathetic modulation in the acute phase (T1) compared to baseline (T0). The HRV alterations remained stable after 6 months (T2). Conclusion BLT reduced global variability and complexity of cardiac autonomic modulation in acute phases, and these alterations remain stable after 6 months from surgery. After BLT, a sympathetic predominance and a vagal withdrawal could be a characteristic autonomic pattern in this population.

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Impact of cerebral aneurysm size on distal intracranial hemodynamics and changes following flow diversion

Interventional Neuroradiology ◽

10.1177/15910199211032467 ◽

2021 ◽

pp. 159101992110324

Author(s):

Denise Brunozzi ◽

Alfred See ◽

Mark Rizko ◽

Jason Choi ◽

Gursant Atwal ◽

...

Keyword(s):

Cerebral Aneurysm ◽

Pulsatility Index ◽

Pressure Ratio ◽

Systolic Pressure ◽

Flow Diversion ◽

Aneurysm Size ◽

Before And After ◽

Mean Pressure ◽

The Mean ◽

The Impact

Background The impact of cerebral aneurysm size on distal intracranial hemodynamics such as arterial pressure and Pulsatility Index is not completely understood, either before or after flow diversion. Objective The aim of the study is to assess the impact of aneurysm size on distal Pulsatility Index and pressure before and after flow diversion. Methods From December 2015, prospective measurement of middle cerebral artery pressure and Pulsatility Index was performed in consecutive patients with unruptured cerebral aneurysms in the cavernous to communicating segments of the internal carotid artery, which were treated with single flow diversion. Pressure and Pulsatility Index were recorded at the M1-segment ipsilateral to the cerebral aneurysm. Ratio of middle cerebral artery to radial arterial pressure (pressure ratio) was calculated to control for variations in systemic blood pressure. Correlations between aneurysm size and pressure ratio and Pulsatility Index were assessed before and after treatment. Results A total of 28 aneurysms were treated. The mean aneurysm size was 7.2 mm. Aneurysm size correlated linearly with systolic pressure ratio (1% pressure ratio increase per mm aneurysm size increase, P = 0.002, r2 = 0.33), mean pressure ratio (0.6% per mm, P = 0.03, r2 = 0.17) and Pulsatility Index (5% Pulsatility Index increase per mm, P = 0.003, r2 = 0.43). After flow diversion, aneurysm size preserved a linear correlation with the systolic pressure ratio (1% per mm, P = 0.004, r2 = 0.28), but not with the mean pressure ratio (0.4% per mm, P = 0.15, r2 < 0.1) or Pulsatility Index (0.3% per mm, P = 0.78, r2 < 0.1). Conclusion Aneurysm size affects distal hemodynamics: patients with larger aneurysms have increased systolic and mean pressure ratio, and increased Pulsatility Index. After flow diversion, mean pressure ratio and Pulsatility Index no longer associate with the aneurysm size, suggesting an effect of the flow diversion also on distal intracranial hemodynamics.

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Thermographic and anthropometric assessment of electrical stimulation on localized body fat

Fisioterapia em Movimento ◽

10.1590/1980-5918.030.001.ao03 ◽

2017 ◽

Vol 30 (1) ◽

pp. 29-37

Author(s):

Graciele Guimarães Pitelli Aroca ◽

Larissa Granato Viana ◽

Rafaela Ferreira de Araújo Costa ◽

Dalilia Schmildt ◽

Ligia de Sousa

Keyword(s):

Electrical Stimulation ◽

Body Fat ◽

Subcutaneous Tissue ◽

Intervention Group ◽

Low Frequency ◽

Control Group ◽

Controlled Clinical Trial ◽

Significance Level ◽

Before And After ◽

And Control

Abstract Introduction: Adiposity is defined as the accumulation of energy reserves within the adipose tissue at specific body sites. Low-frequency electrical stimulation elicits lipolysis. When applied by insertion of needles into the dermis-hypodermis junction, it leads to a modification of the interstitial space, favoring metabolic changes and lipolysis. Objective: To investigate the effects of electrical stimulation on body fat localized to the abdomen and flanks. Methods: Randomized, controlled clinical trial consisted of two groups of women with body fat localized to the abdomen and flanks. The intervention group (IG) was made up of 9 women (± 24,77 years) who received ten sessions of electrical stimulation, whereas the control group (CG) was made up of 7 women (± 21,8 years) who did not receive electrical stimulation. Perimetric, adipometric and thermographic data were collected before and after the intervention. Data were analyzed using the Shapiro-Wilk test, t test, one-way ANOVA. The significance level was set at p < 0,05. Results: There were statistically significant differences between the intervention and control groups in the assessment immediately following intervention (IG: 33.08 ± 1.00; CG: 30.83 ± 1.5; p = 0.002), 15 minutes following intervention (IG: 33.05 ± 0.48; CG: 30.40± 1.24; p < 0.0001) and at the endpoint (IG: 32.22 ± 14.20; CG: 30.53 ± 1.34; p=0.005) for the thermographic data. For the anthropometric variables, there were no statistically significant differences before and after treatment. Conclusion: Electrical stimulation evokes a significant increase in the temperature of the subcutaneous tissue.

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