Variabilité de Fréquence Cardiaque (HRV / rMSSD) & Pilotage de la Récupération

BACKGROUND: Self-myofascial release (SMFR) is a type of myofascial release performed by the individual themselves rather than by a clinician, typically using a tool. OBJECTIVES: To review the literature regarding studies exploring acute and chronic clinical effects of SMFR. METHODS: PubMed and Google Scholar databases were searched during February 2015 for studies containing words related to the topic of SMFR. RESULTS: Acutely, SMFR seems to increase flexibility and reduce muscle soreness but does not impede athletic performance. It may lead to improved arterial function, improved vascular endothelial function, a…

The insula is a brain structure implicated in disparate cognitive, affective, and regulatory functions, including interoceptive awareness, emotional responses, and empathic processes. While classically considered a limbic region, recent evidence from network analysis suggests a critical role for the insula, particularly the anterior division, in high-level cognitive control and attentional processes. The crucial insight and view we present here is of the anterior insula as an integral hub in mediating dynamic interactions between other large-scale brain networks involved in externally oriented attention and inter…

BACKGROUND: Fascial or myofascial unwinding is a process in which a client undergoes a spontaneous reaction in response to the therapist's touch. It can be induced by using specific techniques that encourage a client's body to move into areas of ease. Unwinding is a popular technique in massage therapy, but its mechanism is not well understood. In the absence of a scientific explanation or hypothesis of the mechanism of action, it can be interpreted as "mystical." PURPOSE: This paper proposes a model that builds on the neurobiologic, ideomotor action, and consciousness theories to explain the process and mechanis…

BACKGROUND: Anorexia nervosa (AN) is characterized by low body weight, disturbed eating, body image disturbance, anxiety, and interoceptive dysfunction. However, the neural processes underlying these dysfunctions in AN are unclear. This investigation combined an interoceptive pharmacological probe, the peripheral β-adrenergic agonist isoproterenol, with resting-state functional magnetic resonance imaging to examine whether individuals with AN relative to healthy comparison participants show dysregulated neural coupling in central autonomic network brain regions. METHODS: Resting-state functional magnetic resonanc…

This study investigated acute responses and post 24-h recovery to four running sessions performed at different intensity zones by supine heart rate variability, countermovement jump, and a submaximal running test. A total of 24 recreationally endurance-trained male subjects performed 90 min low-intensity (LIT), 30 min moderate-intensity (MOD), 6×3 min high-intensity interval (HIIT) and 10×30 s supramaximal-intensity interval (SMIT) exercises on a treadmill. Heart rate variability decreased acutely after all sessions, and the decrease was greater after MOD compared to LIT and SMIT (p<0.001; p<0.01) and HIIT compar…

A high heart rate and a low heart rate variability at rest are established predictors of various forms of functional impairment, morbidity, and mortality [1–6]. Two explanations can be given for these associations. On one hand, a high heart rate and a low heart rate variability are thought to reflect dysfunction of the flexible autonomic regulation of the heart rate in particular and of the body's functioning in general that arises during ageing [3–5]. On the other hand, a high heart rate and a low heart rate variability are brought about by cardiovascular risk factors, such as obesity, hyperlipidaemia, diabetes,…

This review presents hormonal responses to various cold exposures and their calorigenic effects in man and some animals. Previous studies in rats have shown that cold exposures activate the hypothalamic-pituitary-thyroid axis. Increased thyroid hormone concentrations lead to heat production via general stimulation of metabolism (obligatory thermogenesis) and possibly via activation of thyroid hormone receptors and uncoupling protein 1 (UCP 1) and deiodinase enzyme genes in the brown adipose tissue (BAT). In human subjects long-term cold exposures do not seem to activate the pituitary-thyroid axis, but rather acce…

This study examined the effects on healthy adults of a new emotional self-management program, consisting of two key techniques, "Cut-Thru" and the "Heart Lock-In." These techniques are designed to eliminate negative thought loops and promote sustained positive emotional states. The hypotheses were that training and practice in these techniques would yield lowered levels of stress and negative emotion and cortisol, while resulting in increased positive emotion and DHEA levels over a one-month period. In addition, we hypothesized that increased coherence in heart rate variability patterns would be observed during t…

BACKGROUND: Moderate regular physical activity is indicated to avoid atrial fibrillation (AF), whereas athletes should be counseled that long-lasting vigorous sports engagement may cause AF, according to the 2016 European Society of Cardiology (ESC) recommendations for AF treatment. Exercise and AF are complex. OBJECTIVES: To evaluate the relationship between Endurance training and AF, in addition to the starting point/trigger by which Endurance Training causes impairment of cardiac function and AF, considering the time and intensity of Endurance training. MATERIALS AND METHODS: We synthesized evidence from artic…

PURPOSEː: The current study aimed at assessing the effect of a trial of two nights of sleep deprivation (SDT) on mood, sleepiness, motivation and cognitive and motor performance. METHODSː: Thirty-six healthy young and physically active adult men (17 in the control group and 19 in the SDT group) completed a 48-h control or 48-h SDT. For the SDT, participants did not sleep for 48 h. Executive function (attention and inhibitory control) in the Go/No-Go and Stroop tests, mood, sleepiness, motivation, heart rate variability (HRV), motor performance in a hand grip strength test, and 60-s maximal isometric contraction (…

It has been demonstrated that heart rate variability (HRV) is predictive of all-cause and cardiovascular mortality using clinical ECG recordings. This is true for rest, exercise and ambulatory HRV clinical ECG device recordings in prospective cohorts. Recently, there has been a rapid increase in the use of mobile health technologies (mHealth) and commercial wearable fitness devices. Most of these devices use ECG or photo-based plethysmography and both are validated for providing accurate heart rate measurements. This offers the opportunity to make risk information from HRV more widely available. The physiology of…

PURPOSE: This study aimed at examining the autonomic cardiovascular modulation in well-trained masters and young cyclists following high-intensity interval training (HIT). METHODS: Nine masters (age 55.6 ± 5.0 years) and eight young cyclists (age 25.9 ± 3.0 years) completed a HIT protocol of 6 x 30 sec at 175% of peak power output, with 4.5-min' rest between efforts. Immediately following HIT, heart rate and R-R intervals were monitored for 30-min during passive supine recovery. Autonomic modulation was examined by i) heart rate recovery in the first 60-sec of recovery (HRR60); ii) the time constant of the 30-min…

Healthy biological systems exhibit complex patterns of variability that can be described by mathematical chaos. Heart rate variability (HRV) consists of changes in the time intervals between consecutive heartbeats called interbeat intervals (IBIs). A healthy heart is not a metronome. The oscillations of a healthy heart are complex and constantly changing, which allow the cardiovascular system to rapidly adjust to sudden physical and psychological challenges to homeostasis. This article briefly reviews current perspectives on the mechanisms that generate 24 h, short-term (~5 min), and ultra-short-term (<5 min) HRV…

Heart rate variability (HRV) is a relevant marker reflecting cardiac modulation by sympathetic and vagal components of the autonomic nervous system (ANS). Although the clinical application of HRV is mainly associated with the prediction of sudden cardiac death and assessing cardiovascular and metabolic illness progression, recent observations have suggested its applicability to physical exercise training. HRV is becoming one of the most useful tools for tracking the time course of training adaptation/maladaptation of athletes and in setting the optimal training loads leading to improved performances. However, lit…

: During exercise, there is a progressive reduction in the ability to produce muscle force. Processes within the nervous system as well as within the muscles contribute to this fatigue. In addition to impaired function of the motor system, sensations associated with fatigue and impairment of homeostasis can contribute to the impairment of performance during exercise. This review discusses some of the neural changes that accompany exercise and the development of fatigue. The role of brain monoaminergic neurotransmitter systems in whole-body endurance performance is discussed, particularly with regard to exercise i…

BACKGROUND: Autonomic regulation of heart rate (HR) as an indicator of the body's ability to adapt to an exercise stimulus has been evaluated in many studies through HR variability (HRV) and post-exercise HR recovery (HRR). Recently, HR acceleration has also been investigated. OBJECTIVE: The aim of this systematic literature review and meta-analysis was to evaluate the effect of negative adaptations to endurance training (i.e., a period of overreaching leading to attenuated performance) and positive adaptations (i.e., training leading to improved performance) on autonomic HR regulation in endurance-trained athlet…

The purpose of this study was to document the physiological changes that occur in a natural bodybuilder during prolonged contest preparation for a proqualifying contest. During the 26-week preparation, the athlete undertook a calorically restrictive diet with 2 days of elevated carbohydrate intake per week, increased cardiovascular (CV) training, and attempted to maintain resistance-training load. The athlete was weighed twice a week and body composition was measured monthly by DXA. At baseline and every 2 weeks following CV structure and function was measured using a combination of ultrasound, applanation tonome…

The measurement of heart rate variability (HRV) is often considered a convenient non-invasive assessment tool for monitoring individual adaptation to training. Decreases and increases in vagal-derived indices of HRV have been suggested to indicate negative and positive adaptations, respectively, to endurance training regimens. However, much of the research in this area has involved recreational and well-trained athletes, with the small number of studies conducted in elite athletes revealing equivocal outcomes. For example, in elite athletes, studies have revealed both increases and decreases in HRV to be associat…

Heart rate (HR) variability (HRV) during ambulatory recordings may be affected by individual differences in daily physical activity (PA). However, the influence of various levels of PA on different measures of HRV is not exactly known. We examined the association between simultaneously measured HRV and objective PA data obtained with an accelerometer during waking hours among 45 healthy adults. Bouts of PA were identified from minute-by-minute accelerometer data as metabolic equivalent (METs) values and calculated as mean METs for 30 min. HRV was analyzed concurrently. Within-individual correlation analyses and s…

Purpose of this study was to test utility of heart rate variability (HRV) in daily endurance exercise prescriptions. Twenty-six healthy, moderately fit males were randomized into predefined training group (TRA, n = 8), HRV-guided training group (HRV, n = 9), and control group (n = 9). Four-week training period consisted of running sessions lasting 40 min each at either low- or high-intensity level. TRA group trained on 6 days a week, with two sessions at low and four at high intensity. Individual training program for HRV group was based on individual changes in high-frequency R-R interval oscillations measured ev…

BACKGROUND: Benefits of moderate endurance training include increases in parasympathetic activity and baroreflex sensitivity (BRS) and a relative decrease in sympathetic tone. However, the effect of very intensive training load on neural cardiovascular regulation is not known. We tested the hypothesis that strenuous endurance training, like in high-performance athletes, would enhance sympathetic activation and reduce vagal inhibition. METHODS AND RESULTS: We studied the entire Italian junior national team of rowing (n=7) at increasing training loads up to 75% and 100% of maximum, the latter approximately 20 days …

Overtraining is an imbalance between training and recovery. Short term overtraining or 'over-reaching' is reversible within days to weeks. Fatigue accompanied by a number of physical and psychological symptoms in the athlete is an indication of 'staleness' or 'overtraining syndrome'. Staleness is a dysfunction of the neuroendocrine system, localised at hypothalamic level. Staleness may occur when physical and emotional stress exceeds the individual coping capacity. However, the precise mechanism has yet to be established. Clinically the syndrome can be divided into the sympathetic and parasympathetic types, based…

The importance of autonomic nervous activity for the pancreatic hormonal response to exercise in man was studied. 7 men ran at 58% of V(O2)max (determined without administration of drugs) to exhaustion during alpha-adrenergic blockade with phentolamine (P), during parasympathetic blockade with atropine (A), or without drugs (C). At rest phentolamine increased the plasma concentrations of both insulin and norepinephrine. During exercise norepinephrine concentrations increased and were in P experiments 3 times the concentrations in C experiments. Insulin always declined during exercise but in P experiments never de…