Heart Rate Variability Recovery Research Articles

Recovery of heart rate and heartrate variability after a maximal cardiopulmonary exercise test in novice female runners.

Previous studies have shown delayed cardiac vagal reactivation after high-intensity endurance exercise when estimated with heartrate variability (HRV). However, the recovery dynamics of RR intervals (RRI) and HRV after a maximal incremental exercise test have been studied less in non-athletic population and especially in females. The main aim of the study was to examine the recovery dynamics of RRI and HRV immediately after a maximal cardiopulmonary exercise test (CPET) in adult females. Twenty-eight healthy, novice recreational female runners (33.7 ± 4.2years) were selected to participate in this study from a larger group of participants (Run RCT). RRIs were collected continuously during a controlled rest, a CPET on a treadmill and a 15-min controlled, passive recovery. Minute-by-minute recovery dynamics were analyzed. The dynamic phase of RRI and heart rate recovery (HRR) (from 192.2 ± 9.9 to 111.4 ± 2.4, P < 0.001) occurred during the first 4.5min with HRR of 36 ± 10 beats during the first minute of the recovery. Resting heart rate was negatively associated (r = - 0.53, P = 0.016) with HRR during the recovery. No recovery of root mean square of successive RRIs (RMSSD) was detected during the 15-min recovery. RMSSD was 15.0 ± 9.2% of resting values at the end of the recovery. No recovery of vagal-derived HRV was detected immediately after a CPET in novice recreational female runners despite marked changes in sympathovagal balance, detected by rapid recovery of RRI during the first 5min after exercise cessation.

Reliability of an "At-Home" Method for Monitoring Resting and Reactive Autonomic Nervous System Activity in Children: A Pilot Study.

Heart rate variability (HRV), an index of the functional status of the autonomic nervous system (ANS), provides an opportunity for early detection of ANS dysfunction. Lower resting, vagally related HRV parameters are associated with increased risk of physical and mental illness. External factors influencing the ANS, such as the testing environment, may impact the interpretation of HRV. This study's main aim was to determine the reliability of HRV resting and reactivity tests performed at home with children aged 4-9 years. Fourteen healthy children (female n = 8) aged 6.8 ± 1.5 years participated. Two HRV tests were performed at home via online supervision 7 days apart using a Polar H10 heart rate monitor. The absolute and relative reliability of the pre-exercise resting (5 min) and sub-maximal exercise step test recovery (4 × 30 s segments) HRV time and frequency domains were calculated. The Pearson correlation coefficients for day 1 versus day 7 for the vagal activity HRV domains (RMSSD log) at rest and in the first 30 s and 30-60 s of recovery indicated good-to-excellent relative reliability (r > 0.8, p < 0.01). Absolute reliability was moderate for the resting RMSSD log, with a coefficient of variation (CV) of 5.2% (90% CI: 3.9, 7.8%), high for the first 30 s of standing recovery, with a CV of 10.7% (90% CI: 8.2, 15.7%), and moderate for 30-60 s of recovery, with a CV of 8.7% (90% CI: 6.6, 12.9%). The findings of this pilot study indicate that the resting and exercise recovery HRV measures of vagal activity can be measured reliably at home in children. This represents a novel "at-home" protocol for monitoring ANS health and development in children.

Autonomic Rebound Following Maximal Exercise in Bodybuilders and Recreationally Active Participants.

The off-season for natural bodybuilders (BB) is characterized by increased training loads and fluctuations in caloric intake, which may lead to insufficient recovery. The autonomic nervous system (ANS) plays a pivotal role in recovery. The purpose of this study was to evaluate resting ANS activity and recovery following a maximal exercise bout in off-season BB and compare them to those of recreationally active individuals. Fifteen males participated; 7 recreationally active (RA) (24.6 ± 2.1 years, 81.1 ± 10.8 kg) and 8 BB (21.8 ± 2.9 years, 89.3 ± 13.0 kg). Each performed a graded exercise test. Heart rate variability (HRV) was measured at rest and during a 45 min recovery period. HRV was analyzed as: root mean square of successive differences (lnRMSSD), standard deviation of normal-to-normal sinus beats (lnSDNN), high frequency (lnHF), low frequency (lnLF), and the ratio of low frequency to high frequency (lnLF/lnHF). A one-way ANOVA showed no differences for any resting marker of HRV, HR, and HR recovery. A significant depression in all markers of HRV was observed in the BB group at the 15 min point, and no recovery was observed before 45 min when compared to RA. The results of this study demonstrated depressed HRV recovery following the graded exercise test in BB when compared to the RA group.

Exploring Contextual Factors in Vagal Tank Theory

High baseline Heart rate variability (HRV) is a putative measure of resilience which predicts adaptive HRV changes during (Reactivity) and after (Recovery) a stressor according to Vagal Tank Theory. However, we do not understand how the availability of resources prior to a stressor impacts this relationship. Using an ecological framework, we tested VTT hypotheses while examining receptivity to social presence and contemplative practices as a moderator to Reactivity and Recovery during a subsequent stressor. Using ECG, we modeled HRV as the root-mean square of successive R-R intervals (RMSSD) across four conditions: baseline, post contemplative practice, directly before a CO2 breathing tasking, while breathing CO2, and after CO2. Reactivity and Recovery were defined as the usual subtraction for phasic HRV literature, while Receptivity was modeled as post contemplative practice HRV minus baseline. Our multiple regression analyses showed that higher baseline predicted greater reactivity, positively interacting with the female gender and the partner condition (F(9,83)=2.00, p=0.04). Higher baseline predicted lower recovery HRV with no significant interactions (F(9,85)=2.66, R2=0.22, p=0.009), potentially due to the benefit in the HRV level at the reference level (after contemplative practice). Higher receptivity predicted higher recovery, with women showing the strongest relationship (F(4,88)=16.3, R2=0.43, p&lt;0.001). Our results suggest that both baseline and receptivity to resources may impact resilience to stress, and that future research should account for gendered effects. Cornell University. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Heart Rate Variability and Coronary Artery Bypass Grafting: A Systematic Review.

Coronary artery bypass grafting (CABG) is a well-established surgical procedure used to treat significant coronary artery disease. Nevertheless, unfavorable cardiovascular events and complications, including cardiac arrhythmias may be observed in patients after CABG. Previous studies have revealed a relationship between risk of cardiac arrhythmias and abnormal heart rate variability (HRV), which reflects adverse alterations in cardiac autonomic functioning, that may occur in patients after a CABG procedure. The aim of this article was to provide a systematic review of the major research findings in this area. A literature search was carried out using PubMed, Cochrane, and Embase databases and relevant articles, published in English, were analyzed in detail. Studies performed so far have shown time depending changes in HRV after CABG. Time and frequency domain HRV decrease acutely after CABG but recover almost completely to pre-operative values by 6 months after surgery. Some preoperative clinical states such as: heart failure, type 2 diabetes mellitus and depression adversely affect post-CABG HRV. Finally, post-CABG cardiac rehabilitation appears to improve exercise capacity and speed up recovery of HRV. Generally, traditional time and frequency domain HRV parameters fail to predict complications post-CABG. Altered non-linear measures of HRV may identify subgroups of subjects at increased risk of potential complications, including atrial fibrillation post-CABG. However, data available currently does not appear to unequivocally support the hypothesis that early HRV assessment in post-CABG patients predicts long-term mortality.

Predicting Post-Traumatic Stress Disorder Treatment Response Using Heart Rate Variability to Virtual Reality Environment and Modified Stroop Task: An Exploratory Study.

Predicting treatment response can inform treatment decisions, expectations, and optimize use of mental health treatment resources. This study examined heart rate (HR), heart rate variability (HRV), and a modified Stroop task (mStroop) to predict post-traumatic stress disorder (PTSD) treatment response. We report on an observational, longitudinal study with 45 U.S. veterans in outpatient PTSD care, who had deployed to Iraq or Afghanistan. HR and HRV were collected before, during, and after virtual reality (VR) combat and civilian scenes. HRV recovery was defined as HRV after a 3-minute VR simulation minus HRV during a VR scene. mStroop threat variables included index scores for combat and general threat. Self-report data were collected at baseline and 6 months later. The outcome variable was the 17-item Clinician Administered PTSD Scale (CAPS). Controlling for baseline CAPS and number of combat experiences, the following baseline HRV recovery variables were significant predictors of 6-month CAPS: standard deviation of normal beat to beat interval (SDNN) after combat scene minus SDNN during combat scene and low-frequency (LF HRV) after civilian scene minus LF during civilian scene. HRV at rest, HR reactivity, HR recovery, and mStroop scores did not predict treatment response. In conclusion, HRV recovery variables in the context of a standardized VR stressor were significant predictors of PTSD treatment response after controlling for baseline CAPS and number of combat experiences. The direction of this relationship indicates that greater baseline HRV recovery predicts lower 6-month PTSD symptom severity. This was an exploratory study in need of replication.

Heart Rate Variability, Autonomic Reactivity, and Emotion Regulation during Sadness Induction in Somatic Symptom Disorder.

Preliminary evidence suggests altered heart rate variability (HRV) and impaired emotion regulation (ER) in somatic symptom disorder (SSD). Moreover, HRV can be considered an index of ER. Yet, to date, research on HRV and emotional reactivity in SSD is scarce and findings are inconsistent. Thus, this study aimed to examine ER differences, HRV at rest, and in response to emotion induction in persons with SSD compared to controls. The sample comprised 44 persons with SSD (DSM-5; 79.5% female, Mage = 45.7, SD = 14.7) and 41 persons without SSD (non-SSD; 78% female, Mage = 44.2, SD = 14.7). We assessed the participants' somatic symptom severity, ER, and control variables (e.g., depressive symptoms). Frequency and time domain HRV by ECG and subjective emotional states were measured at rest, under sadness induction, and during recovery periods. We evaluated baseline between-group differences with t-tests, and HRV and emotional reactivity and recovery with repeated measures ANOVAs. We found no significant differences in resting state HRV between persons with and without SSD. Regarding reactivity and recovery, SSD group showed lower reactivity in SDNN (standard deviation of NN interval) than non-SSD group. Moreover, SSD group reported more maladaptive ER techniques (e.g. rumination) and a higher effort to regulate their emotions during the experiment than non-SSD group. The study indicated impaired ER in persons with SSD. This finding showed more clearly in self-report than in HRV. Further research on HRV reactivity including tasks evoking other negative emotions in persons with SSD is required.

Subjective and objective measurements of nurses’ stress and recovery

Abstract Objectives High workloads and stress of healthcare workforce are global phenomena. We aimed to study work related stress and recovery of nurses with both subjective and objective methods, also aiming to examine if associations exist between subjective high work stress and need for recovery, and objectively measured stress and recovery. Methods Study sample comprised 65 nurses employed in the City of Helsinki. Heart rate variability (HRV) measurements were conducted for 3 consecutive days with ECG-based device in real-life setting, including 2 workdays and 1 day off. Objective stress and recovery were assessed from HRV and HRV-based stress and recovery variables. Participants filled out an electronic survey, where work stress was measured with Effort-reward imbalance scale and recovery after work with Need for recovery scale. Results Proportion of nurses with effort-reward ratio &amp;gt;1, indicating work stress, was high (84.6%), as was proportion of those with high need for recovery (64.6%). High need for recovery (score ≥54.5) was associated with lower RMSSD during sleep (p = 0.014) and higher absolute stress index (p = 0.009) on workdays. In high need for recovery group, stress balance (p = 0.040) and relaxation percentage (p = 0.033) were significantly lower on workdays than day off. In moderate work stress group, stress balance (p = 0.042), relaxation percentage (p = 0.041) and absolute relaxation index (p = 0.035) were lower on workdays than day off. No significant differences were observed within other groups. Conclusions Majority of participants suffered from work stress or high need for recovery. Based on our results, nurses’ high need for recovery is reflected in lower sleep time HRV, indicating worse physiological recovery. In those with high need for recovery, physiological recovery was also worse on workdays when compared with day off. Our findings highlight the importance of recovery, and in the future, nurses’ recovery and work stress should be increasingly monitored. Key messages • Nurses’ high need for recovery is reflected in lower sleep time heart rate variability. • Nurses’ recovery and work stress should be increasingly monitored.

Post-exercise heart rate variability recovery after 800-m endurance run load among Cameroonian adolescent's males

The 800-m (m) run is part of Physical Education classes in Cameroon, after which arrhythmias may occur during recovery. Hence, this study aimed at determining relationship between 800-m run loads on cardiac autonomic recovery among school adolescents.Forty-two male adolescents (aged [17 ​± ​1] years) performed 800-m. Post-exercise heart rate variability (HRV) was recorded during 5-min (min) (HRV5-min) and 15-min (HRV15-min) in time: Standard deviation of normal to normal (SDNN); Root mean square of successive differences (RMSSD) and frequency domain (LH: Low frequency, HF: High frequency, TP: Total power). Rating of Perceived Exertion (RPE) and blood lactate concentration (BLa) were measured after exercise. In HRV5-min, RPE was associated with SDNN (r ​= ​−0.44, p ​< ​0.01) and RMSSD (r ​= ​−0.38, p ​< ​0.05). BLa was correlated with SDNN (r ​= ​−0.38, p ​< ​0.05) and RMSSD (r ​= ​−0.56, p ​< ​0.001) in the time-domain, LF (r ​= ​−0.64, p ​< ​0.001), HF (r ​= ​−0.58, p ​< ​0.001) and TP (r ​= ​−0.61, p ​< ​0.001) in frequency-domain. Moreover, RPE was correlated with LF (r ​= ​−0.44, p ​< ​0.01), TP (r ​= ​−0.49, p ​< ​0.01) while exercise duration with HF (r ​= ​−0.38, p ​< ​0.05). In HRV15-min, BLa was correlated with RMSSD (r ​= ​−0.53, p ​< ​0.001) and SDNN (r ​= ​−0.68, p ​< ​0.001). RPE was negatively correlated SDNN (r ​= ​−0.53, p ​< ​0.01) and RMSSD (r ​= ​−0.44, p ​< ​0.01). BLa was associated with HF (r ​= ​−0.55, p ​< ​0.001), TP (r ​= ​−0.50, p ​< ​0.01) and RPE with LF (r ​= ​−0.51, p ​< ​0.01), HF (r ​= ​−0.50, p ​< ​0.01), TP (r ​= ​−0.49, p ​< ​0.01). In addition, exercise duration was negatively linked to HF (r ​= ​−0.36, p ​< ​0.05). This study outlined that in untrained adolescents an increase of 800-m loads is associated with a slow vagal indexes of HRV during the recovery.

Heart rate variability in patients with acute ST-segment elevation myocardial infarction after COVID-19

Aim. To compare heart rate variability parameters in patients after a coronavirus disease 2019 (COVID-19) with acute ST elevation myocardial infarction (STEMI) during the inhospital and post-hospital periods.Material and methods. A total of 140 patients with STEMI were divided into 2 groups: I — patients with STEMI who had COVID-19 (n=52) in the period of 1,5-6 months before acute coronary syndrome, II — comparison group (n=88), which included patients with STEMI without prior COVID-19. All patients underwent infarct-related artery stenting within the first 24 hours from the onset. Heart rate variability (HRV) parameters were determined for all patients on days 2-3 and days 9-11 and 6 months after the hospitalization for STEMI.Results. Patients in group I showed more pronounced changes in HRV indicators on days 2-3 of STEMI: RMSSD (root square of successive RR intervals) by 21% (p=0,026), variations (Var) (the difference between the minimum and maximum RR intervals) by 33% (p=0,013), VLF (total very low-frequency HRV) by 7% (p=0,009) were higher, and HF (highfrequency HRV) by 40% (p=0,003), pNN50% (ratio of the number of consecutive RR interval pairs differing by &gt;50 ms to the total number of RR intervals) by 66% (p=0,038) were lower than in the control group, respectively. On days 9-11 of the disease in patients with a history of STEMI and COVID-19, in contrast to the control group, there was a more pronounced increase in the SDNN (standard deviation of RR intervals) by 46% (p=0,005), VLF by 42% (p=0,031), whereas in the control group there were an increase of only 22% (p=0,004) and 11% (p=0,022), respectively. The HF value in the main group increased by 25% (p=0,007), while in the control group it decreased by 19% (p=0,030). Six months after STEMI in the main group, the RMSSD decreased by 19% (p=0,009), Var by 16% (p=0,041), VLF by 30% (p=0,025), LF (low-frequency component HRV) by 11% (p=0,005), while the control group these parameters decreased by 20% (p=0,006), 21% (p=0,001), 9% (p=0,011), and 7% (p=0,016), respectively.Conclusion. In patients with STEMI and prior COVID-19, the initial HRV values differ from similar HRV parameters in patients with STEMI without prior COVID-19. In the hospital and post-hospital periods, the changes of HRV in patients with and without COVID-19 are multidirectional as follows: pronounced sympathetic hyperactivity predominates, and slower recovery of HRV in patients after COVID-19 predominates.

Comparative study of Heart Rate variability in pregnant women living in conditions of High-mountain Hypoxia of the Pamirs and the steppe zone of Central Kazakhstan

A comparative analysis of the main indicators of heart rate variability was carried out in 72 women aged 25-35 with a normal course of pregnancy, 90-30 days and 10-5 days before delivery, living in different geographical areas: high-mountainous region of Tajikistan (Pamir, Murghab village, 3600-4200m above sea level) and the steppe region of Central Kazakhstan (546m above sea level). The mechanism of compensatory-adaptive reactions, which is not typical for other regions, was revealed in pregnant women living in conditions of high-altitude hypoxia. In women living in the territory of Central Kazakhstan, at 90-30 days before delivery, pregnancy proceeded against the background of increased activity of the sympathetic division of the autonomic nervous system (SD of ANS). Recovery of heart rate variability (HRV) began 10–5 days before term birth, which is the result of a decrease in the effectiveness of adrenergic effects and an increase in the effectiveness of M-cholinergic effects on heart rate, according to some authors1,2. These changes in HRV can be successfully used as a biological marker of a mother’s readiness for childbirth, taking into account the availability and safety of the HRV method. In Pamir women, an increase in the activity of the parasympathetic division (PD) of ANS was noted 90-30 days before childbirth, and persisted until delivery. Starting from the third trimester of pregnancy, the dynamics of the values of such parameters as AMo (amplitude mode), ARI (autonomic rhythm index), RMSD (root mean square deviation), VR (variation range) showed a optimal functional state of regulatory systems before childbirth. This was also evidenced by the value of the stress index, which was in the range of 194-197 units. This mechanism of regulation in the conditions of high-altitude hypoxia ensures the normal development of the fetus and the mobilization of the functional reserves of newborns during childbirth and after birth.

A brief body scan mindfulness practice has no positive effect on the recovery of heart rate variability and cognitive tasks in female professional basketball players.

In this study, we examined the acute effects of a short video-based body scan mindfulness practice on the heart rate variability (HRV) and cognitive performance of professional female basketball players after the first half of a simulated basketball game. In this crossover randomized controlled trial, nine professional athletes completed a physical loading protocol on two separate days. The protocol consisted of a 10-min Yo-Yo Intermittent Recovery Test Level 1 in the first quarter, followed by a 10-min basketball game in the second quarter. Immediately afterward, they were asked to engage in a 10-min mindfulness practice or watch a 10-min nature-based documentary as a type of mental intervention. Their HRV, Rating of Perceived Exertion (RPE), National Aeronautics and Space Administration Task Load Index 2 (NASA TLX-2), and Go/No-Go test scores were recorded immediately before and after the physical loading and after the mental intervention. The physical demand, effort, and frustration level subscales of the NASA TLX-2 and the RPE scores were found to be significantly higher after the physical loading, and they returned to the baseline level after both types of mental intervention. The Go/No-Go test scores did not differ depending on the measurement time. All time- and frequency-domain heart rate variability parameters, except the low-to-high frequency ratio, were found to be significantly high immediately after the physical loading protocol. However, these parameters returned to their initial levels after both types of mental intervention. Completing the tests involved in the study protocol successfully induced physical fatigue, as evidenced by consistent measurement tools, but the one-time and short-term mindfulness practice had no additional benefits for the recovery of heart rate variability, cognitive tasks, or subjective assessment methods, such as RPE and NASA TLX-2, in basketball players with no previous experience of mindfulness practice.

A systematic review of heart rate variability (HRV) biofeedback treatment following traumatic brain injury (TBI)

ABSTRACT Objective Autonomic nervous system dysregulation is a common consequence of traumatic brain injury (TBI). Heart rate variability (HRV) is a cost-effective measure of autonomic nervous system functioning, with studies suggesting decreased HRV following moderate-to-severe TBI. HRV biofeedback treatment may improve post-TBI autonomic nervous system functioning and post-injury emotional and cognitive functioning. We provide a systematic evidence-based review of the state of the literature and effectiveness of HRV biofeedback following TBI. Method We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two coders coded each article and provided quality ratings. Seven papers met inclusion criteria. All studies included a measure of emotional functioning and 5 studies (63%) included neuropsychological outcomes. Results Participants completed 11 sessions of HRV biofeedback on average (range = 1 to 40). HRV biofeedback was associated with improved HRV following TBI. There was a positive relationship between increased HRV and TBI recovery following biofeedback, including improvements in cognitive and emotional functioning, and physical symptoms such as headaches, dizziness, and sleep problems. Conclusion The literature on HRV biofeedback for TBI is promising, but in its infancy; effectiveness is unclear due to poor-to-fair study quality, and potential publication bias (all studies reported positive results).

Phase-change material cooling blanket: A feasible cooling choice during transport after exercise-induced hyperthermia

BackgroundExercise-induced hyperthermia preceding the onset of exertional heatstroke requires a rapid reduction in the body core temperature (Tcore) to ensure safety. In recent years, phase-change material (PCM) cooling devices have been increasingly used for rapid cooling after hyperthermia due to their superior capacity for heat absorption. ObjectivesThis study aimed to evaluate the cooling performance and effectiveness of a PCM cooling blanket on heart rate (HR) and heart rate variability (HRV) recovery after exercise-induced hyperthermia. DesignRandomized cross-over. MethodsThe study participants were 12 male volunteers who were engaged in professional training and completed an endurance exercise for approximately 30 min in a hot and humid environment (temperature ≈ 30 °C; relative humidity ≈ 66%). The participants underwent a 30-min cooling trial after exercise, receiving either treatment with a PCM cooling blanket (PCM group) or natural cooling (CON group). The Tcore, HR, and HRV time-domain indices were used for analysis. ResultsThe Tcore values were significantly lower in the PCM group during cooling. Reductions in the Tcore from precooling to 20 min of cooling were significantly greater in the PCM group than in the CON group. The HR in the PCM group was lower than that recorded in the CON group at 10 and 20 min of cooling. The reduction in HR during cooling from precooling was also significantly greater in the PCM group. HRV time-domain indices during cooling in the PCM group were significantly lower compared with the CON group while elevations in some HRV time-domain indices from precooling to postcooling were significantly greater in the PCM group than in the CON group. ConclusionsThe PCM cooling blanket had good cooling performance and the ability to hasten recovery of both HR and HRV. It may serve as a feasible cooling choice during transport after exercise-induced hyperthermia.

Associations between Autonomic and Endocrine Reactivity to Stress in Adolescence: Related to the Development of Anxiety?

Internalizing disorders in adolescence have been associated with disturbances in autonomic and endocrine functioning. Because the prefrontal cortex and the limbic system play a central role in regulating both the autonomic and the endocrine systems, their joint functioning is hypothesized to provide information about the potential development of internalizing symptoms throughout adolescence, notably in the preclinical stage. This hypothesis was tested in a sample of 198 adolescents from the general population. Heart rate variability (HRV) and skin conductance levels (SCLs) were measured before, during, and after a public speaking task. These autonomic parameters were associated with cortisol response to the task in the complete sample as well as in low- and high-anxiety adolescents separately. Self-reported social anxiety, low HRV, and high SCL recovery values were predictive of cortisol response. Importantly, in low-anxiety adolescents, only HRV during the task predicted the cortisol response, whereas, in their highly anxious peers, both HRV and SCL were strongly associated with this response. In the latter finding, age was a prominent factor. Additional analyses supported the idea that the interaction of autonomic and endocrine reactivity is subject to natural development. These findings provide evidence that adolescence might be a period of highly interactive emotional-neurobiological development, particularly with respect to the development of stress management skills.

Acute effects of energy drink on heart rate variability recovery after exercise: A systematic review and meta-analysis

The influence of energy drink (ED) on the analysis of autonomic parameters through post-exercise heart rate variability (HRV) remains undefined. We propose to assess the results of the principal studies that estimated the acute effects of ED intake on HRV recovery after effort. Searches were completed in the following databases: PubMed, MEDLINE via Ovid, Embase, Web of Science, CINAHL, Cochrane Library, Bireme, MedRxiv, and Scopus. The research commenced between July 2020 and March 2021. The terms necessary to identify the studies were “Energy Drink” AND “Exercise” AND “Recovery” AND “Heart Rate Variability”. Only clinical, crossover, and placebo-controlled trials were suitable for the final sample. Four studies were considered eligible, studies could not demonstrate significant values akin to the intervention with ED. The total sample size for performing the meta-analysis was 59 participants. The 99% confidence interval (CI) of our meta-analysis ranged from −2.13 to 0.36 with a combined effect size of −0.89 for SDNN , −1.34 to 0.10 with a combined effect size from −0.62 for RMSSD. Our review supports that ED intake did not change the post-exercise HRV recovery in healthy adults. L’influence de la prise de boisson énergisante (BE) sur la variabilité de la fréquence cardiaque post-exercice (VFC) reste mal définie. Nous proposons d’évaluer les résultats des principales études qui ont estimé les effets en aigu de la prise de BE sur la récupération de la VRC après effort. Les recherches ont été effectuées dans les bases de données suivantes: PubMed, MEDLINE via Ovid, Embase, Web of Science, CINAHL, Cochrane Library, Bireme, MedRxiv et Scopus. La recherche a commencé entre juillet 2020 et mars 2021. Les termes nécessaires pour identifier les études étaient « Boisson énergisante » ET « Exercice » ET « Récupération » ET « Variabilité de la fréquence cardiaque ». Seuls les essais cliniques, croisés et contrôlés par placebo étaient inclus dans l’échantillon final. Quatre études ont été considérées comme éligibles. Ces études n’ont pas pu démontrer d’effet significatif de la BE sur la VFC. La taille totale de l’échantillon pour effectuer la méta-analyse était de 59 participants. L’intervalle de confiance (IC) à 99 % de notre méta-analyse variait de −2,13 à 0,36 avec une taille d’effet combinée de −0,89 pour SDNN , −1,34 à 0,10 avec une taille d’effet combinée de −0,62 pour RMSSD. Notre revue montre que la prise d’ED n’a pas modifié la récupération de la VFC après exercice chez des adultes en bonne santé.

Fluid Replacement Strategies and Heart Rate Variability Recovery Following Prolonged Exercise in the Heat and Mild Dehydration

Background: In sporting and combat settings, optimal fluid replacement is rarely achieved, exacerbating physiological strain. It is unknown if prescribed fluid replacement following exercise in heat impacts heart rate variability (HRV). Purpose: Compare prescribed drinking (PD) and ad libitum (AL) fluid replacement on HRV following exercise in heat. Methods: Twelve participants (26 ± 5 years, VO2max: 58.44 ± 7.05 mL·kg−1·min−1) completed three trials in heat (36 °C, 36% humidity) on separate days, and were placed into groups, PD or AL. Recovery was assessed ~24 h later (hydration and HRV). HRV time and frequency was measured using a 3-lead electrocardiogram. Two-way repeated measures analysis of variance measured changes in HRV pre-trial, post-trial, and follow-up between groups. Data reported: p-value, mean difference (MD). Results: Fluid consumption was greater in PD during recovery (p = 0.012, MD = 1245 mL). Both groups were euhydrated at follow-up. HRV time (p &lt; 0.001, MD = 24.23) and frequency (p &lt; 0.001, MD = −1.98 ms2) decreased post-trial and increased by follow-up (time, p &lt; 0.001, MD = −32.12; frequency, p &lt; 0.001, MD = 2.38 ms2). HRV was similar between groups (p &gt; 0.05). Conclusions: Replacing ≥60% fluid sufficiently rehydrates and restores HRV 24 h post-exercise in heat and mild dehydration (BML ≤ 3%). Prescribed fluid consumption during recovery was ~30% greater. Additional measures of recovery sensitive to heat strain may provide a more holistic understanding of specific mechanisms of recovery.

Wingate Testi Sırasında Ultra Kısa Süreli Kalp Atış Hızı Değişkenliğinin Non-invaziv Değerlendirilmesi

The aim of present study was to investigate the sedentary healthy men’s ultra-short heart rate variability (HRV) during the Wingate Anaerobic Test (WAnT) (30-sec) and parasympathetic reactivation in the first 60-sec after WAnT. The final sample comprised 101 individuals (Mean±SD; Age=28.9±4.8 years, Height=176.5±5.5 cm, Weight=89.8±8.8 kg). Anaerobic powers were measured by WAnT. Heart rate variability (HRV) was then recorded as 60-sec before the test for 30-sec and 60-sec after the test. HRV was measured by Polar V800 GPS Sports Watch with Heart Rate Monitor and Polar H7 band. To compare the testing stages HRV parameters, repeated one-way analysis of variance (ANOVA) was used. Binary comparisons were determined with the Bonferroni test. The relationship between exercise data of heart rate variability and power average watt was assessed by the Pearson correlation test. The Effect Size Cohen's d was calculated. The main finding of this study is that pre-test (60-sec) HRV values continue to drop dramatically during test (30-sec) and post-test (60-sec) measurements (p&amp;lt;0.05). Also, no correlation was observed between performance and HRV data during testing (r=-0.08, p&amp;gt;0.05). In conclusion, the present study was not observed to sign of HRV recovery during 60-sec after the 30-sec WAnT. HRV recorded in the first 60 seconds after maximum anaerobic exercise program in sedentary healthy men may be considered to exhibit an imbalance in the parasympathetic activity of the autonomic nervous system.

Effects of acute resistance exercise with different loads on appetite, appetite hormones and autonomic nervous system responses in healthy young men

Although the effect of continuous aerobic exercise on the appetite has been widely explored, the influence of resistance exercise (RE) with different variables, including training loads, training volume, and inter-set rest, on appetite responses requires further investigation. This study examined the importance of training load in RE-induced appetite regulation, with the total training volume and inter-set rest equalized. In total, 11 healthy young men (age = 23 ± 2 years, body mass index = 22 ± 2 kg/m2) were included. Participants completed 3 trials, namely moderate-load RE (MOD; 4 sets of 8 repetitions at 85% 8RM), low-load RE (LOW; 4 sets of 15 repetitions at 45% 8RM), and a control (CON; no exercise), in a randomized, crossover design. Subjective appetite ratings; concentrations of ghrelin, peptide YY (PYY), and lactate; and the autonomic nervous system activity were evaluated before exercise and 1 h after exercise. The hunger and predicted food consumption ratings, and ghrelin concentrations immediately after exercise were significantly lower in the MOD and LOW trials (p < 0.05 vs. CON). The PYY and lactate concentrations immediately after exercise were significantly higher in the MOD and LOW trials (p < 0.05 vs. CON). Heart rate variability recovery was slower in the MOD trial. These findings suggest that both moderate-load and low-load RE at equal training volumes and inter-set rest induce similar responses on hunger suppression and orexigenic signals, except for the slower recovery of autonomic modulation after moderate-load RE. Our results suggest that when individuals aim to potentiate appetite suppression after a bout of RE, both moderate- and low-load RE could be applied.

Recovery After Stress-Autonomic and Subjective Arousal in Individuals With Psychosis Compared to Healthy Controls.

Heightened stress levels in individuals with psychosis (PSY) are associated with psychotic symptom occurrence and may be partially attributed to well-established deficits in resting-state heart rate variability (HRV) and emotion regulation. In healthy participants, resting-state HRV and self-reported emotion regulation skills have been linked to recovery after a stressor; however, it is unclear whether stress recovery is altered in PSY. Thus, we compared the autonomic and subjective recovery of PSY to healthy controls (HC) and investigated the predictive value of resting-state HRV and emotion regulation skills. We assessed resting-state HRV and self-reported emotion regulation one week prior to a combined physical and cognitive stress induction. After the stress exposure, we assessed the autonomic (decrease in heart rate [HR], increase in HRV) and subjective (decrease in subjective stress and negative affect) recovery in PSY (n = 50) and HC (n = 50) over 60 min. Repeated-measures ANOVA revealed the expected interaction of time × group for subjective stress but not negative affect or autonomic stress. Resting-state HRV predicted recovery of HR, and emotion regulation skills predicted recovery of HRV but not of the other parameters. Although subjective stress recovery was delayed in PSY, the absence of autonomic recovery deficits suggests that a prolonged stress response may not contribute to heightened stress levels to the expected extent. Improving resting-state HRV and emotion regulation may support autonomic recovery, but further investigation is required to test the impact of such improvements on psychotic symptoms.