Monitoring fatigue state with heart rate-based and subjective methods during intensified training in recreational runners.

The purpose of this study was firstly to examine the sensitivity of heart rate (HR)-based and subjective monitoring markers to intensified endurance training; and secondly, to investigate the validity of these markers to distinguish individuals in different fatigue states. A total of 24 recreational runners performed a 3-week baseline period, a 2-week overload period, and a 1-week recovery period. Performance was assessed before and after each period with a 3000m running test. Recovery was monitored with daily orthostatic tests, nocturnal HR recordings, questionnaires, and exercise data. The participants were divided into subgroups (overreached/OR, n = 8; responders/RESP, n = 12) based on the changes in performance and subjective recovery. The responses to the second week of the overload period were compared between the subgroups. RESP improved their baseline 3000 m time (p < 0.001) after the overload period (-2.5 ± 1.0%), and the change differed (p < 0.001) from OR (0.6 ± 1.2%). The changes in nocturnal HR (OR 3.2 ± 3.1%; RESP -2.8 ± 3.7%, p = 0.002) and HR variability (OR -0.7 ± 1.8%; RESP 2.1 ± 1.6%, p = 0.011) differed between the subgroups. In addition, the decrease in subjective readiness to train (p = 0.009) and increase in soreness of the legs (p = 0.04) were greater in OR compared to RESP. Nocturnal HR, readiness to train, and exercise-derived HR-running power index had ≥85% positive and negative predictive values in the discrimination between OR and RESP individuals. In conclusion, exercise tolerance can vary substantially in recreational runners. The results supported the usefulness of nocturnal HR and subjective recovery assessments in recognizing fatigue states.

Aerobic high-intensity interval training and maximal strength training in patients with unspecific musculoskeletal disorders improve V̇O2peak and maximal strength more than moderate training.

Improving peak oxygen uptake (V̇O2peak) and maximal strength are key objectives of rehabilitation for patients with unspecific musculoskeletal disorders (MSDs). Although high-intensity training yield superior outcomes for these factors, patients with MSDs may not tolerate high-intensity due to pain and fear. Therefore, we examined the effect and feasibility of incorporating aerobic high-intensity intervals (HIITs) and maximal strength training (MST) in a standard clinical rehabilitation program for patients with unspecific MSDs. 73 patients (45 ± 10 years) with MSDs partaking in a standard, public, and 4-week rehabilitation program were randomized to high-intensity training (HG: 4 × 4 minutes intervals at ∼90% of maximal heart rate; HRmax, and 4 × 4 repetitions leg press at ∼90% of 1 repetition maximum; 1RM, with maximal intended velocity) or keep todays treatment of low-to moderate-intensity training (MG: various cycling, walking, and/or running activities at ∼70%-80% of HRmax and 3 × 8 - 10 repetitions leg press at ∼75% of 1RM without maximal intended velocity). HG improved V̇O2peak (12 ± 7%) and leg press 1RM (43 ± 34%) more than moderate-intensity group (V̇O2peak; 5 ± 6%, 1RM; 19 ± 18%, both p < 0.001). We observed that no adverse events and no between-group differences in dropout rate or self-reported quality of life (both p > 0.05). There were positive correlations between improved V̇O2peak and improved physical (p = 0.024) and emotional (0.016) role functioning. We conclude that both high-intensity interval training and MST are feasible and improve V̇O2peak and maximal strength more than standard low-to moderate-intensity treatment of patients with unspecific MSDs. Our findings suggest that high-intensity training should be implemented as a part of standard clinical care of this patient population.

Adjunctive hiking bouts during 8 weeks regular sailing training improves cardiorespiratory and muscular responses during hiking emulation in highly trained sailors.

To investigate the effects of 8-week hiking bench training on cardiorespiratory and muscular responses of highly trained sailors during hiking emulation. Twenty-four sailors were assigned into two groups: the hiking bench training group (HTG, n = 12) and the control group (CG, n = 12). Both groups maintained their regular training with the HTG performed two additional hiking bench training sessions per week for 8 weeks, while the CG performed an equivalent duration of on-water sailing training. Physiological responses were assessed by performing four successive 3-min hiking bouts on a sailing emulation ergometer before and after the 8-week training period. Comparing the pretest, both groups exhibited a significant decrease (p < 0.05) in the percentage of maximal oxygen uptake (%VO2max) and maximal heart rate (%HRmax); the HTG experienced a greater decrease in %VO2max in bouts 2 and 3. The root mean square (RMS) of rectus femoris (RF), vastus lateralis (VL), rectus abdominis (RA), and external oblique decreased significantly (p < 0.05), whereas the mean power frequency (MPF) of RF, VL, and RA exhibited an increasing trend. The RMS of RF and RA in HTG were lower than those in CG in the initial three bouts; VL and EA in HTG were lower than those in CG in bouts 1 and 2 (p < 0.05). The MPF of RA in HTG was significantly increased in bouts 2, 3, and 4 (p < 0.05). Eight-week hiking bench training could improve hiking economy and the activation of lower limb and trunk muscles delaying the onset of fatigue in sailors.

Noncontact Sensors for Vital Signs Measurement: A Narrative Review.

Vital signs are crucial for monitoring changes in patient health status. This review compared the performance of noncontact sensors with traditional methods for measuring vital signs and investigated the clinical feasibility of noncontact sensors for medical use. We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE) database for articles published through September 30, 2023, and used the key search terms "vital sign," "monitoring," and "sensor" to identify relevant articles. We included studies that measured vital signs using traditional methods and noncontact sensors and excluded articles not written in English, case reports, reviews, and conference presentations. In total, 129 studies were identified, and eligible articles were selected based on their titles, abstracts, and full texts. Three articles were finally included in the review, and the types of noncontact sensors used in each selected study were an impulse radio ultrawideband radar, a microbend fiber-optic sensor, and a mat-type air pressure sensor. Participants included neonates in the neonatal intensive care unit, patients with sleep apnea, and patients with coronavirus disease. Their heart rate, respiratory rate, blood pressure, body temperature, and arterial oxygen saturation were measured. Studies have demonstrated that the performance of noncontact sensors is comparable to that of traditional methods of vital signs measurement. Noncontact sensors have the potential to alleviate concerns related to skin disorders associated with traditional skin-contact vital signs measurement methods, reduce the workload for healthcare providers, and enhance patient comfort. This article reviews the medical use of noncontact sensors for measuring vital signs and aimed to determine their potential clinical applicability.

Assessment of Heat Exposure and Health Outcomes in Rural Populations of Western Kenya by Using Wearable Devices: Observational Case Study.

BACKGROUND: Climate change increasingly impacts health, particularly of rural populations in sub-Saharan Africa due to their limited resources for adaptation. Understanding these impacts remains a challenge, as continuous monitoring of vital signs in such populations is limited. Wearable devices (wearables) present a viable approach to studying these impacts on human health in real time. OBJECTIVE: The aim of this study was to assess the feasibility and effectiveness of consumer-grade wearables in measuring the health impacts of weather exposure on physiological responses (including activity, heart rate, body shell temperature, and sleep) of rural populations in western Kenya and to identify the health impacts associated with the weather exposures. METHODS: We conducted an observational case study in western Kenya by utilizing wearables over a 3-week period to continuously monitor various health metrics such as step count, sleep patterns, heart rate, and body shell temperature. Additionally, a local weather station provided detailed data on environmental conditions such as rainfall and heat, with measurements taken every 15 minutes. RESULTS: Our cohort comprised 83 participants (42 women and 41 men), with an average age of 33 years. We observed a positive correlation between step count and maximum wet bulb globe temperature (estimate 0.06, SE 0.02; P=.008). Although there was a negative correlation between minimum nighttime temperatures and heat index with sleep duration, these were not statistically significant. No significant correlations were found in other applied models. A cautionary heat index level was recorded on 194 (95.1%) of 204 days. Heavy rainfall (>20 mm/day) occurred on 16 (7.8%) out of 204 days. Despite 10 (21%) out of 47 devices failing, data completeness was high for sleep and step count (mean 82.6%, SD 21.3% and mean 86.1%, SD 18.9%, respectively), but low for heart rate (mean 7%, SD 14%), with adult women showing significantly higher data completeness for heart rate than men (2-sided t test: P=.003; Mann-Whitney U test: P=.001). Body shell temperature data achieved 36.2% (SD 24.5%) completeness. CONCLUSIONS: Our study provides a nuanced understanding of the health impacts of weather exposures in rural Kenya. Our study's application of wearables reveals a significant correlation between physical activity levels and high temperature stress, contrasting with other studies suggesting decreased activity in hotter conditions. This discrepancy invites further investigation into the unique socioenvironmental dynamics at play, particularly in sub-Saharan African contexts. Moreover, the nonsignificant trends observed in sleep disruption due to heat expose the need for localized climate change mitigation strategies, considering the vital role of sleep in health. These findings emphasize the need for context-specific research to inform policy and practice in regions susceptible to the adverse health effects of climate change.

Blunted brachial blood flow velocity response to acute mental stress in PTSD females.

Post-traumatic stress disorder (PTSD) is associated with increased cardiovascular disease (CVD) risk. Compared with males, females are twice as likely to develop PTSD after trauma exposure, and cardiovascular reactivity to stress is a known risk factor for CVD. We aimed to examine hemodynamic responses to acute mental stress in trauma-exposed females with and without a clinical diagnosis of PTSD. We hypothesized that females with PTSD would have higher heart rate (HR), blood pressure (BP), and lower blood flow velocity (BFV) responsiveness compared with controls. We enrolled 21 females with PTSD and 21 trauma-exposed controls. We continuously measured HR using a three-lead electrocardiogram, BP using finger plethysmography, and brachial BFV using Doppler ultrasound. All variables were recorded during 10 min of supine rest, 5 min of mental arithmetic, and 5 min of recovery. Females with PTSD were older, and had higher BMI and higher resting diastolic BP. Accordingly, age, BMI, and diastolic BP were covariates for all repeated measures analyses. Females with PTSD had a blunted brachial BFV response to mental stress (time × group, p = 0.005) compared with controls, suggesting greater vasoconstriction. HR and BP responses were comparable. In conclusion, our results suggest early impairment of vascular function in premenopausal females with PTSD.

Examining the feasibility and utility of heart rate variability on intervention outcomes targeting emotion regulation in autism: a brief report.

Autistic youth experience several behavioral and emotional characteristics that can predispose them to emotion dysregulation (ED). Current literature examining ED in autism spectrum disorder (ASD) is limited to parent- and self-reported measures, indicating a need for biological or physiological methods to better assess emotion regulation in ASD. Utilizing the autonomic nervous system, specifically heart rate variability (HRV), may be a promising method to objectively measure ED in ASD, given it is one of the body's primary means of regulating physiological arousal. Our pilot study is one of the first to examine the feasibility, utility, and construct validity of HRV along with clinical measures within an intervention targeting ED-specific symptoms in ASD. Participants included 30 autistic youth ages 8-17 years who participated in the pilot study of Regulating Together, a group-based intervention targeting emotion regulation. We demonstrate HRV is feasible, demonstrates adequate test-retest reliability, and is complimentary to clinician- and parent-reported measures. Our preliminary findings also point to certain HRV profiles being indicative of long-term outcomes after receiving treatment. HRV may be a useful, objective tool in determining differential needs of long-term follow-up care for treatment maintenance at screening or baseline stages.

Joint association of sedentary time and physical activity with abnormal heart rate recovery in young and middle-aged adults.

BACKGROUND: Abnormal heart rate recovery (HRR), representing cardiac autonomic dysfunction, is an important predictor of cardiovascular disease. Prolonged sedentary time (ST) is associated with a slower HRR. However, it is not clear how much moderate-to-vigorous physical activity (MVPA) is required to mitigate the adverse effects of sedentary behavior on HRR in young and middle-aged adults. This study aimed to examine the joint association of ST and MVPA with abnormal HRR in this population. METHODS: A cross-sectional analysis was conducted on 1253 participants (aged 20-50 years, 67.8% male) from an observational study assessing cardiopulmonary fitness in Fujian Province, China. HRR measured via cardiopulmonary exercise tests on a treadmill was calculated as the difference between heart rate at peak exercise and 2 min after exercise. When the HRR was ≤ 42 beats·minute-1 within this time, it was considered abnormal. ST and MVPA were assessed by the IPAQ-LF. Individuals were classified as having a low sedentary time (LST [< 6 h·day-1]) or high sedentary time (HST [≥ 6 h·day-1]) and according to their MVPA level (low MVPA [0-149 min·week-1], medium MVPA [150-299 min·week-1], high MVPA [≥ 300 min·week-1]). Finally, six ST-MVPA groups were derived. Associations between ST-MVPA groups with abnormal HRR incidence were examined using logistic regression models. RESULTS: 53.1% of the young and middle-aged adults had less than 300 min of MVPA per week. In model 2, adjusted for possible confounders (e.g. age, sex, current smoking status, current alcohol consumption, sleep status, body mass index), HST was associated with higher odds of an abnormal HRR compared to LST (odds ratio (OR) = 1.473, 95% confidence interval (CI) = 1.172-1.852). Compared with the reference group (HST and low MVPA), the HST and high MVPA groups have a lower chance of abnormal HRR (OR, 95% CI = 0.553, 0.385-0.795). Compared with individuals with HST and low MVPA, regardless of whether MVPA is low, medium, or high, the odds of abnormal HRR in individuals with LST is significantly reduced (OR, 95% CI = 0.515, 0.308-0.857 for LST and low MVPA; OR, 95% CI = 0.558, 0.345-0.902 for LST and medium MVPA; OR, 95% CI = 0.476, 0.326-0.668 for LST and high MVPA). CONCLUSION: Higher amounts of MVPA appears to mitigate the increased odds of an abnormal HRR associated with HST for healthy young and middle-aged adults.

Psychophysiological responses to a multimodal physiotherapy program in fighter pilots with flight-related neck pain: A pilot trial.

BACKGROUND: The physical and cognitive demands of combat flying may influence the development and persistence of flight-related neck pain (FRNP). The aim of this pilot study was to analyse the effect of a multimodal physiotherapy program which combined supervised exercise with laser-guided feedback and interferential current therapy on psychophysiological variables in fighter pilots with FRNP. METHODS: Thirty-one fighter pilots were randomly assigned to two groups (Intervention Group: n = 14; Control Group: n = 17). The intervention consisted of 8 treatment sessions (twice per week) delivered over 4 weeks. The following primary outcomes were assessed: perceived pain intensity (Numeric Pain Rating Scale-NPRS) and Heart Rate Variability (HRV; time-domain, frequency-domain and non-linear variables). A number of secondary outcomes were also assessed: myoelectric activity of the upper trapezius and sternocleidomastoid, pain catastrophizing (Pain Catastrophizing Scale-PCS) and kinesiophobia (TSK-11). RESULTS: Statistically significant differences (p≤0.05) within and between groups were observed for all outcomes except for frequency domain and non-linear HRV variables. A significant time*group effect (one-way ANOVA) in favour of the intervention group was found for all variables (p<0.001). Effect sizes were large (d≥0.6). CONCLUSIONS: The use of a multimodal physiotherapy program consisting of supervised exercise with laser-guided feedback and interferential current appears to show clinical benefit in fighter pilots with FRNP. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05541848.

Vagal predominance correlates with mood state changes of winter-over expeditioners during prolonged Antarctic residence.

OBJECTIVE: Winter-over expeditioners in Antarctica are challenged by various environmental and psycho-social stress factors, which may induce psychophysiological changes. The autonomic nervous system (ANS) plays a crucial role in the adaptation process under stress. However, the relationship between ANS activity and the mood states of expeditioners remains largely unexplored. This study aims to uncover the pattern of ANS adjustment under extreme Antarctic environments and provide new insights into the correlations between ANS activity and mood state changes, which may provide scientific data for medical interventions. METHODS: Fourteen expeditioners at Zhongshan Station participated in this study. The study was conducted during four representative periods: pre-Antarctica, Antarctica-1 (pre-winter), Antarctica-2 (winter), and Antarctica-3 (summer). The heart rate variability (HRV) of the expeditioners was continuously measured for 24 hours to evaluate ANS activity. Plasma levels of catecholamines were tested by ELISA. Mood states were assessed by the Profile of Mood States (POMS) scale. RESULTS: HRV analysis showed a disturbance of ANS during winter and summer periods. For frequency domain parameters, very low frequency (VLF), low frequency (LF), high frequency (HF), and total power (TP) significantly increased during the second half of the mission. Especially, LF/HF ratio decreased during summer, indicating the predominance of vagal tone. Results of the time domain analysis showed increased heart rate variability during the austral winter and summer. Plasma epinephrine (E) significantly increased during residence in Antarctica. Compared with pre-Antarctica, the vigor, depression, and anger scores of the expeditioners decreased significantly during the austral summer. Notably, the depression score showed a moderate positive correlation with LF/HF, while weak negative correlations with other HRV indicators, including TP, VLF, and LF. Anger score showed a moderate positive correlation with LF/HF and weak negative correlations with the average normal-to-normal (NN) interval, and the root mean square of differences between adjacent RR intervals (RMSSD). Plasma E level weakly correlated with the average NN interval. CONCLUSION: Prolonged residence in Antarctica increased the ANS activities and shifted the cardiac autonomic modulation towards vagal predominance. The alteration of HRV correlated with mood states and plasma epinephrine levels.

Cardiac autonomic regulation following a 246-km mountain ultra-marathon: An observational study.

Physical exercise requires integrated autonomic and cardiovascular adjustments to maintain homeostasis. We aimed to observe acute posture-related changes in blood pressure, and apply a portable noninvasive monitor to measure the heart index for detecting arrhythmia among elite participants of a 246-km mountain ultra-marathon. Nine experienced ultra-marathoners (8 males and 1 female) participating in the Run Across Taiwan Ultra-marathon in 2018 were enrolled. The runners' Heart Spectrum Blood Pressure Monitor measurements were obtained in the standing and supine positions before and immediately after the race. Their high-sensitivity troponin T and N-terminal proB-type natriuretic peptide levels were analyzed 1 week before and immediately after the event. Heart rate was differed significantly in the immediate postrace assessment compared to the prerace assessment, in both the standing (P = .011; d = 1.19) and supine positions (P = .008; d = 1.35). Postural hypotension occurred in 4 (44.4%) individuals immediately postrace. In 3 out of 9 (33.3%) recruited finishers, the occurrence of premature ventricular complex signals in the standing position was detected; premature ventricular complex signal effect was observed in the supine position postrace in only 1 participant (11.1%). Premature ventricular complex signal was positively correlated with running speed (P = .037). Of the 6 individuals who completed the biochemical tests postrace, 2 (33.3%) had high-sensitivity troponin T and 6 (100%) had N-terminal proB-type natriuretic peptide values above the reference interval. A statistically significant increase was observed in both the high-sensitivity troponin T (P = .028; d = 1.97), and N-terminal proB-type natriuretic peptide (P = .028; d = 2.91) levels postrace compared to prerace. In conclusion, significant alterations in blood pressure and heart rate were observed in the standing position, and postexercise (postural) hypotension occurred among ultra-marathoners. The incidence of premature ventricular complexes was higher after the race than before.

Sinus rhythm restoration reverses tricuspid regurgitation in patients with atrial fibrillation: a systematic review and meta-analysis.

BACKGROUND: Tricuspid regurgitation (TR) is a common valvular heart disease worldwide, and current guidelines for TR treatment are relatively conservative, as well as with detrimental outcomes. Restoration of sinus rhythm was reported to improve the TR severity in those TR patients with atrial fibrillation (AF). However, relevant research was limited. The aim of this meta-analysis was to evaluate the clinical outcomes of restoration of sinus rhythm in TR patients with AF. METHODS: In this study, PubMed, Web of Science, and Scopus databases were searched for study enrollment until July 2023. This study was designed under the guidance of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. These studies containing the patient's baseline characteristics, surgical procedure, and at least one of the clinical outcomes were included. The primary endpoint was TR grade during follow-up after restoration of sinus rhythm. RESULTS: Out of 1074 records, 6 were enrolled. Restoration of sinus rhythm is associated with a reduction of TR severity (TR grade, odds ratio 0.11, 95% confidence interval (CI): 0.01 to 1.28, P = 0.08, I2 = 83%; TR area, mean difference (MD) -2.19 cm2, 95% CI: -4.17 to -0.21 cm2, P = 0.03, I2 = 96%). Additionally, remolding of right heart with a significant reduction of tricuspid valve annulus diameter (MD -0.36 cm, 95%CI: -0.47 to -0.26 cm, P < 0.00001, I2 = 29%) and right atrium volume index (MD -11.10 mL/m2, 95%CI: -16.81 to -5.39 mL/m2, P = 0.0001, I2 = 79%) was observed during follow-up. CONCLUSIONS: In conclusion, rhythm-control therapy could reduce TR severity in AF patients with TR and is associated with right heart remodeling.

Sex-related differences in young binge drinkers on the neurophysiological response to stress in virtual reality.

Background: Stress is one of the main environmental factors involved in the onset of different psychopathologies. In youth, stressful life events can trigger inappropriate and health-damaging behaviors, such as binge drinking. This behavior, in turn, can lead to long-lasting changes in the neurophysiological response to stress and the development of psychological disorders late in life, e.g., alcohol use disorder. Our aim was to analyze the pattern of neurophysiological responses triggered with the exposition to a stressful virtual environment in young binge drinkers. Methods: AUDIT-3 (third question from the full AUDIT) was used to detect binge drinking (BD) in our young sample (age 18-25 years). According to the score, participants were divided into control (CO) and BD group. Next, a standardized virtual reality (VR) scenario (Richie's Plank) was used for triggering the stress response while measuring the following neurophysiological variables: brain electrical activity by electroencephalogram (EEG) and cortisol levels through saliva samples both measurements registered before and after the stressful situation. Besides, heart rate (HR) with a pulsometer and electrodermal response (EDA) through electrodes placed on fingers were analyzed before, during and after the VR task. Results: Regarding the behavior assessed during the VR task, BD group spent significantly less amount of time walking forward the table and a tendency toward more time walking backwards. There was no statistically significant difference between the BD and the CO group regarding time looking down, but when we controlled the variable sex, the BD women group displayed higher amount of time looking down than the rest of the groups. Neurophysiological measurements revealed that there was not any statistically significant difference between groups in any of the EEG registered measures, EDA response and cortisol levels. Sex-related differences were found in HR response to VR scenario, in which BD women displayed the highest peak of response to the stressor. Also, the change in heartbeat was higher in BD women than men. Conclusion: Unveiling the neurophysiological alterations associated with BD can help us to prevent and detect early onset of alcohol use disorder. Also, from our data we conclude that participants' sex can modulate some stress responses, especially when unhealthy behaviors such as BD are present. Nevertheless, the moment of registration of the neurophysiological variables respect to the stressor seems to be a crucial variable.

RETRACTED: PO-04-037 ARTIFICIAL INTELLIGENCE FOR ANALYSIS OF MOBILE CARDIAC TELEMETRY.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This abstract has been retracted at the request of the Authors; please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The abstract was withdrawn after being accepted for presentation at Heart Rhythm, the annual meeting of the Heart Rhythm Society, because there was substantial content development after it had been submitted, both in terms of more in-depth analyses and quantitative changes due to final adjudication of events. The Authors intended to withdraw the abstract from publication as well but omitted to do so. The Authors apologize for the inconvenience caused by this oversight.

Comparative Analysis of the Effects of Exercise and Kapalbhati Pranayama on Heart Rate Variability and Electroencephalogram Activity: Unveiling Physiological and Cognitive Insights.

Physical activity and mindfulness techniques, such as exercise and Kapalbhati Pranayama, are known to have positive effects on health and well-being. However, limited research has directly compared their impact on physiological and psychological parameters. This study aimed to investigate and compare the effects of exercise and Kapalbhati Pranayama on Heart Rate Variability (HRV) and Electroencephalogram (EEG) activity, shedding light on their contributions to overall health and mental well-being. The study was conducted at All India Institute of Medical Sciences (AIIMS) in Bhopal, India, from 2018 to 2022. A prospective interventional design was employed over two months, involving 20 participants with normal BMI and no respiratory or cardiac conditions. Exclusion criteria included lung or cardiac diseases, smoking history, dyspnoea during physical activity, pedal edema, and high blood pressure. The Kapalbhati Pranayama intervention was supervised and limited to 5 minutes. HRV was assessed using the HRV Brain Tap Neuralchek Machine before, during, and after Kapalbhati. For exercise, a mild-intensity cycling protocol was performed on healthy volunteers aged 20 to 50. HRV was recorded before, during, and after exercise. The EEG analysis revealed notable changes in brain wave patterns. At baseline, participants exhibited higher levels of delta, theta, and alpha waves, indicating a state of relaxation and calmness. During exercise, there was a significant increase in beta waves and a decrease in delta, theta, and alpha waves, reflecting heightened brain activity and alertness. After Kapalbhati, beta wave levels remained elevated, while delta and theta wave suppression was more pronounced, suggesting a stimulating effect on the brain similar to exercise. The changes in beta and gamma EEG waves could be attributed to factors such as exercise intensity, duration, frequency, and the release of endorphins during both exercise and Kapalbhati. The HRV analysis demonstrated distinct responses to exercise and Kapalbhati. Exercise led to a significant reduction in HRV parameters, characterized by increased heart rate and decreased time-domain HRV measures, aligning with the typical sympathetic nervous system dominance during physical activity. In contrast, Kapalbhati's impact on HRV parameters was milder, with minor changes in heart rate and subtle alterations in time-domain HRV measures. The high LF/HF ratio during Kapalbhati suggested a potential stimulation of the sympathetic nervous system. More comprehensive research is required to confirm these findings and understand the long-term effects of Kapalbhati on HRV and cardiovascular health. This study contributes to the understanding of how exercise and Kapalbhati Pranayama affect both cognitive and cardiovascular aspects of health. It highlights that both interventions increase brain activity and alertness, but Kapalbhati may have a more potent effect. Exercise significantly reduces HRV parameters, indicating sympathetic nervous system dominance, while Kapalbhati has milder HRV effects. Further research with larger and more diverse populations is essential to confirm and expand on these findings, providing insights into optimizing cognitive function and cardiovascular health through tailored approaches of exercise and Kapalbhati Pranayama.

Prefrontal cortex oxygenation during a mentally fatiguing task in normoxia and hypoxia.

Mental fatigue (MF) and hypoxia impair cognitive performance through changes in brain hemodynamics. We want to elucidate the role of prefrontal cortex (PFC)-oxygenation in MF. Twelve participants (22.9 ± 3.5 years) completed four experimental trials, (1) MF in (normobaric) hypoxia (MF_HYP) (3.800 m; 13.5%O2), (2) MF in normoxia (MF_NOR) (98 m; 21.0%O2), (3) Control task in HYP (CON_HYP), (4) Control in NOR (CON_NOR). Participants performed a 2-back task, Digit Symbol Substitution test and Psychomotor Vigilance task before and after a 60-min Stroop task or an emotionally neutral documentary. Brain oxygenation was measured through functional Near Infrared Spectroscopy. Subjective feelings of MF and physiological measures (heart rate, oxygen saturation, blood glucose and hemoglobin) were recorded. The Stroop task resulted in increased subjective feelings of MF compared to watching the documentary. 2-back accuracy was lower post task compared to pre task in MF_NOR and CON_NOR, while no differences were found in the other cognitive tasks. The fraction of inspired oxygen did not impact feelings of MF. Although performing the Stroop resulted in higher subjective feelings of MF, hypoxia had no effect on the severity of self-reported MF. Additionally, this study could not provide evidence for a role of oxygenation of the PFC in the build-up of MF.

Cardiovascular and cardiorespiratory effects of high-intensity interval training in body fat responders and non-responders.

This study aimed to investigate cardiovascular and cardiorespiratory adaptations to exercise intervention among participants who showed higher (responders-RSBFP) and lower (non-responders-NRSBFP) levels of body fat percentage (BFP) responsiveness. Adolescents (42.5% males) participated in a ten-week school-based high-intensity interval training (HIIT), followed by a comparison of BFP, blood pressure (BP), and cardiorespiratory fitness (CRF). RSBFP age of 16.15 ± 0.36 years, body height 170.82 ± 8.16 cm, weight 61.23 ± 12.80 kg, and BMI 20.86 ± 3.29 kg/m2. Meanwhile, NRSBFP age of 16.04 ± 0.36 years, body height 168.17 ± 8.64 cm, weight 57.94 ± 8.62 kg, and BMI 20.47 ± 2.24 kg/m2. HIIT intervention impacted BFP, with a higher decrease in the RSBFP than the NRSBFP (ΔBFPRs = - 2.30 ± 3.51(10.34%) vs. ΔBFPNRs = 1.51 ± 1.54(6.96%) p < 0.001). The primary comparison showed a statistically significant interaction effect in relation to CRF (F(1,71) = 14.12; p < 0.001). Detailed comparisons showed large and significant CRF changes in RSBFP (7.52%; d = 0.86; p < 0.001) but not in NRSBFP (2.01%; d = 0.11; p = 0.576). In addition, RSBFP and NRSBFP benefited equally in SBP (5.49%, d = 0.75; p < 0.001; 4.95%, d = 0.74; p < 0.001, respectively). These findings highlight that exercise benefits on body fat may be mainly related to gains in CRF. Due to substantial intra-individual variability in adaptation, there is a need for personalized intervention tailored for those with different reaction thresholds in body mass components.

A tree-based explainable AI model for early detection of Covid-19 using physiological data.

With the outbreak of COVID-19 in 2020, countries worldwide faced significant concerns and challenges. Various studies have emerged utilizing Artificial Intelligence (AI) and Data Science techniques for disease detection. Although COVID-19 cases have declined, there are still cases and deaths around the world. Therefore, early detection of COVID-19 before the onset of symptoms has become crucial in reducing its extensive impact. Fortunately, wearable devices such as smartwatches have proven to be valuable sources of physiological data, including Heart Rate (HR) and sleep quality, enabling the detection of inflammatory diseases. In this study, we utilize an already-existing dataset that includes individual step counts and heart rate data to predict the probability of COVID-19 infection before the onset of symptoms. We train three main model architectures: the Gradient Boosting classifier (GB), CatBoost trees, and TabNet classifier to analyze the physiological data and compare their respective performances. We also add an interpretability layer to our best-performing model, which clarifies prediction results and allows a detailed assessment of effectiveness. Moreover, we created a private dataset by gathering physiological data from Fitbit devices to guarantee reliability and avoid bias.The identical set of models was then applied to this private dataset using the same pre-trained models, and the results were documented. Using the CatBoost tree-based method, our best-performing model outperformed previous studies with an accuracy rate of 85% on the publicly available dataset. Furthermore, this identical pre-trained CatBoost model produced an accuracy of 81% when applied to the private dataset. You will find the source code in the link: https://github.com/OpenUAE-LAB/Covid-19-detection-using-Wearable-data.git .

Relative Severity of Human Performance Decrements Recorded in Rapid vs. Gradual Decompression.

INTRODUCTION: Cabin decompression presents a threat in high-altitude-capable aircraft. A chamber study was performed to compare effects of rapid (RD) vs. gradual decompression and gauge impairment at altitude with and without hypoxia, as well as to assess recovery.METHODS: There were 12 participants who completed RD (1 s) and Gradual (3 min 12 s) ascents from 2743-7620 m (9000-25000 ft) altitude pressures while breathing air or 100% O2. Physiological indices included oxygen saturation (SPo2), heart rate (HR), respiration, end tidal O2 and CO2 partial pressures, and electroencephalography (EEG). Cognition was evaluated using SYNWIN, which combines memory, arithmetic, visual, and auditory tasks. The study incorporated ascent rate (RD, gradual), breathing gas (air, 100% O2) and epoch (ground-level, pre-breathe, ascent-altitude, recovery) as factors.RESULTS: Physiological effects in hypoxic "air" ascents included decreased SPo2 and end tidal O2 and CO2 partial pressures (hypocapnia), with elevated HR and minute ventilation (V˙E); SPo2 and HR effects were greater after RD (-7.3% lower and +10.0 bpm higher, respectively). HR and V˙E decreased during recovery. SYNWIN performance declined during ascent in air, with key metrics, including composite score, falling further (-75% vs. -50%) after RD. Broad cognitive impairment was not recorded on 100% O2, nor in recovery. EEG signals showed increased slow-wave activity during hypoxia.DISCUSSION: In hypoxic exposures, RD impaired performance more than gradual ascent. Hypobaria did not comprehensively impair performance without hypoxia. Lingering impairment was not observed during recovery, but HR and V˙E metrics suggested compensatory slowing following altitude stress. Participants' cognitive strategy shifted as hypoxia progressed, with efficiency giving way to "satisficing," redistributing effort to easier tasks.Beer J, Mojica AJ, Blacker KJ, Dart TS, Morse BG, Sherman PM. Relative severity of human performance decrements recorded in rapid vs. gradual decompression. Aerosp Med Hum Perform. 2024; 95(7):353-366.

Fueling the heartbeat: Dynamic regulation of intracellular ATP during excitation-contraction coupling in ventricular myocytes.

The heart beats approximately 100,000 times per day in humans, imposing substantial energetic demands on cardiac muscle. Adenosine triphosphate (ATP) is an essential energy source for normal function of cardiac muscle during each beat, as it powers ion transport, intracellular Ca2+ handling, and actin-myosin cross-bridge cycling. Despite this, the impact of excitation-contraction coupling on the intracellular ATP concentration ([ATP]i) in myocytes is poorly understood. Here, we conducted real-time measurements of [ATP]i in ventricular myocytes using a genetically encoded ATP fluorescent reporter. Our data reveal rapid beat-to-beat variations in [ATP]i. Notably, diastolic [ATP]i was <1 mM, which is eightfold to 10-fold lower than previously estimated. Accordingly, ATP-sensitive K+ (KATP) channels were active at physiological [ATP]i. Cells exhibited two distinct types of ATP fluctuations during an action potential: net increases (Mode 1) or decreases (Mode 2) in [ATP]i. Mode 1 [ATP]i increases necessitated Ca2+ entry and release from the sarcoplasmic reticulum (SR) and were associated with increases in mitochondrial Ca2+. By contrast, decreases in mitochondrial Ca2+ accompanied Mode 2 [ATP]i decreases. Down-regulation of the protein mitofusin 2 reduced the magnitude of [ATP]i fluctuations, indicating that SR-mitochondrial coupling plays a crucial role in the dynamic control of ATP levels. Activation of ß-adrenergic receptors decreased [ATP]i, underscoring the energetic impact of this signaling pathway. Finally, our work suggests that cross-bridge cycling is the largest consumer of ATP in a ventricular myocyte during an action potential. These findings provide insights into the energetic demands of EC coupling and highlight the dynamic nature of ATP concentrations in cardiac muscle.