Maximal Heart Rate Research Articles

Improvements in functional exercise performance at 6 months following bariatric surgery: A prospective cohort study

Objectives: Successful weight loss after bariatric surgery has been associated with a variety of improvements in health status. Delayed heart rate recovery after the six-minute walking test (6MWT) is associated with morbidity and mortality in various cardiac and respiratory diseases. We aimed to evaluate the effect of bariatric surgery on functional exercise performance and autonomic dysfunction in patients who had undergone laparoscopic sleeve gastrectomy. Methods: Pre-operative and post-operative (6 months) demographics, comorbidities, weight, and height of the patients undergoing laparoscopic sleeve gastrectomy were recorded. All patients underwent a 6MWT. 6MWT was performed according to the American Thoracic Society standards. Additionally, heart rate (HR) and oxygen saturation were assessed at rest, at the end of the test, and in the first minute following testing. Autonomic dysfunction was assessed by heart rate recovery (HRR), which was calculated as the difference between the maximum HR reached during the 6MWT and the HR at the first minute after the test. Patients were classified depending on whether their HRR was slow (HRR<12 beats, “delayed recovery”) or more rapid (HRR≥12 beats, “non-delayed recovery”). Results: A total of 62 patients were prospectively enrolled. The mean age of the patients was 36.8±9.1 years and 74% were female. Pre-operative and post-operative body mass indices were 48.5±5.2 kg/m2 and 34.4±3.5 kg/m2, respectively (P<0.001). Excess weight loss was 52.7±12.7%. Post-operative six-minute walking distance significantly improved compared to pre-operative period (406±48 meters vs. 443±52 meters, P<0.001). Compared with pre-operative period, perceived breathlessness and fatigue at the end of the 6MWT decreased from 1.3±1.5 to 0.4±0.9 Borg units (P<0.001), and 3.2±2.1 to 0.8±1.4 Borg units (P<0.001), respectively. We observed a remarkable, but statistically non-significant increase in the number of patients in the delayed HRR group from 21% (n=13) to 42% (n=26) in the postoperative period, compared to the preoperative assessment (P=0.12). Conclusions: Laparoscopic sleeve gastrectomy is associated with rapid weight loss and improvements in perceived exertional dyspnea, fatigue and six-minute walking distance at 6 months after surgery. Failure of the heart rate to fall after cessation of exertion, a delayed HRR, has previously been found to be associated with increased mortality in cardiac failure. Further investigation is required to examine the physiological mechanisms involved in autonomic dysfunction, and consequences of delayed HRR after rapid weight loss by bariatric surgery.

Impact of Increasing Levels of Obesity on Functional Capacity and Cardiorespiratory Fitness in Children.

This study aims to evaluate the impact of increasing severity of childhood obesity on cardiorespiratory fitness (CRF) using cardiopulmonary exercise testing. A retrospective analysis of cardiopulmonary exercise testing data from patients <21years of age was performed. Patients were categorized by body mass index percentile into 4 classes. CRF was assessed and compared between groups by relative peak VO2 and metabolic equivalents achieved at limit of tolerance. A total of 204 patients were included in the study. Significantly lower relative peak VO2 and metabolic equivalents and higher adjusted peak VO2 were achieved with increasing obesity. Resting and recovery heart rates (HRs) were significantly higher in Class III compared with the nonobese patients (P = .001 and .003, respectively). Class III patients had a significantly greater HR at anaerobic threshold relative to maximum HR achieved compared with the nonobese patients (P = .002). There was no significant difference between groups in the rating of perceived exertion at peak exercise, peak O2 pulse, or maximum HR achieved. Our study has shown that CRF worsens with increasing levels of obesity. Cardiopulmonary exercise testing can be used as an objective measure to assess CRF as a target for intervention in childhood obesity for pediatricians. Improvement in fitness is an achievable outcome, which also translates into improved cardiometabolic health.

Outcomes of Pediatric Patients with Excessive Postural Tachycardia After Attending an Intensive Interdisciplinary Pain Program: A Pilot Study

Background/Objectives: Adolescents with autonomic disorders who attend Intensive Interdisciplinary Pain Treatment (IIPT) programs report improvements in functioning. However, it is unclear whether they experience corresponding improvements in physiological measures. As such, the aim of this pilot study was to examine changes in physiological measures in youth attending an IIPT program who demonstrated excessive postural tachycardia on an active stand test. The secondary goal was to examine associations between physiological measurements and self-reported measures of chronic orthostatic intolerance (cOI) and functioning. Methods: At admission and discharge, eighteen adolescents and young adults (AYAs) attending IIPT (M age = 17.39 years; SD = 2.15 years) completed an active stand test, measures of breathing rate and muscle tension, as well as self-reported measures of cOI symptoms and functioning. Results: AYAs showed significant reduction in active stand test heart rate increase (p &lt; 0.001; d = 1.07) and maximum heart rate (p = 0.002, d = 0.76) from admission to discharge. Improvements were also observed in resting respiration rate (p = 0.001, d = 89) and resting trapezoid tension (p = 0.03, d = 0.49). Although patients showed significant improvements on self-report measures of functioning (p &lt; 0.001, d = 1.78), changes on subjective report of cOI symptoms did not reach significance. Exploratory analyses that only included patients with a POTS diagnosis were consistent with the overall results. Conclusions: Youth who demonstrated excessive postural tachycardia on active stand test at admission to an IIPT showed significant improvements from admission to discharge in their active stand maximum heart rate and heart rate increase, as well as respiration rate, muscle tension, and reports of their functioning. Future research is necessary to examine the mechanisms of change that contribute to symptom improvement.

Fractal correlation properties of heart rate variability and respiratory frequency as measures of endurance exercise durability.

Field-based measures of durability (exercise-related physiologic deterioration over time) for assessing athletic fitness often rely on changes in maximal power profiles or heart rate (HR) drift. This study aimed to determine whether an index of HR variability based on the short-term exponent of Detrended Fluctuation Analysis (DFA a1) along with respiratory frequency (fB) could demonstrate changes in durability during a Time to Task Failure (TTF) Trial. Ten participants performed a cycling TTF at an intensity of 95% of the respiratory compensation point (RCP) on two occasions, Control and a "Reward" where a monetary incentive was offered when task failure was signaled. Metabolic responses including oxygen uptake ( ), lactate and glucose along with HR, DFA a1 and fB were measured and compared over each quarter of the TTF up to the time of signaling (Q1, Q2, Q3, and Q4). The elapsed time of TTF sessions was statistically similar (p = 0.54). After initial equilibration, metabolic responses remained largely stable over Q2-Q4. HR, DFA a1 and fB displayed drift over Q2-Q4 with significant ANOVA. Repeatability of quarterly HR, DFA a1, and fB between Control and Reward sessions was high with ICC between 0.73 and 0.94, Pearson's r was between 0.83 and 0.98 with no difference in mean values by paired t testing. HR, fB and DFA a1 are useful metrics representing alteration in physiologic characteristics demonstrating durability loss during an endurance exercise session. These measures were repeatable across sessions and have the potential to be monitored retrospectively or in real time in the field with low-cost consumer equipment.

Using Free-Living Heart Rate Data as an Objective Method to Assess Physical Activity: A Scoping Review and Recommendations by the INTERLIVE-Network Targeting Consumer Wearables.

Wearable technologies open up new avenues for the assessment of individual physical activity behaviour. Particularly, free-living heart rate (HR) data assessed by optical sensors are becoming widely available. However, while an abundancy of scientific information and guidance exists for the processing of raw acceleration data, no universal recommendations for the utilization of continuous HR recordings during free-living conditions are available. Towards Intelligent Health and Well-Being: Network of Physical Activity Assessment (INTERLIVE®) is a joint European initiative of six universities and one industrial partner. The consortium was founded in 2019 and strives towards developing best-practice recommendations in the context of consumer wearables and smartphones. The aim of this scoping review (following PRISMA-ScR procedures) and recommendations was to provide best-practice protocols for deriving individual physical activity profiles from continuous HR recordings by wearables. The recommendations were developed through an initial scoping review, grey literature searches of promotional material and user manuals of leading wearable manufacturers as well as evidence-informed discussions among the members of the INTERLIVE®-network. The scoping review was performed on the generic domains required for physical activity assessment, namely: (1) 'assessment of maximal heart rate', (2) 'determination of basal and/or resting heart rate' and (3) 'heart rate-derived intensity zones', for which we finally included a total of 72, 2 and 11 eligible papers, respectively. Gathering recent knowledge, we provide a decision tree and detailed recommendations for the analysis of free-living HR data to derive individual physical activity profiles. Moreover, we also provide examples of HR-metric calculations that help to illustrate data processing and reporting.

Pimobendan oral solution is bioequivalent to pimobendan chewable tablets in beagle dogs.

Myxomatous mitral valve disease (MMVD) is frequently diagnosed in small breed dogs. Pimobendan oral solution has been developed to improve dosing accuracy in small and toy breed dogs. Demonstrate bioequivalence of pimobendan oral solution with pimobendan chewable tablets using a pharmacokinetic and a pharmacodynamic study in healthy purpose bred dogs. In the pharmacokinetic study, 24 beagle dogs were dosed in a 4-period crossover design. In the pharmacodynamic study, 4 mongrel and 2 beagle dogs implanted with telemetry probes were included in a 2-way crossover design. Both studies were designed as prospective, randomized crossover trials. Dogs were given single doses of 5 mg/dog of either formulation followed by serial blood sampling for determination of pimobendan and O-desmethyl-pimobendan (ODMP; main metabolite). Because of high variability in the pharmacokinetics, the reference scaled average bioequivalence (RSABE) method was applied. For the pharmacodynamic study, animals were dosed with 0.25 mg/kg of either formulation. Baseline corrected left ventricular maximal pressure (LVdP/dtmax) and heart rate were recorded continuously and compared with a predefined bioequivalence threshold. Pimobendan was verified as a high variability drug. Based on the RSABE method, both formulations were bioequivalent. Pharmacodynamic results supported bioequivalence. The novel oral solution of pimobendan was found to be bioequivalent, both applying the Food and Drug Administration (FDA) supported RSABE method and based on pharmacodynamic data. Thus, the novel liquid formulation can be used to facilitate accurate dosing of small and toy breed dogs.

THE EFFECT OF ACE’S ON PHYSIOLOGICAL MEASURES OF HEALTH

https://youtu.be/RzKWRGm-J34 BACKGROUND The aim of this study was to determine if Adverse Childhood Experiences (ACE’s) are related to physiological measures of health. ACE’s are associated with an increase in the inflammatory response. Chronic inflammation is linked to diseases such as heart disease, lung disease, and cancer as well as immunologic conditions. Lifestyle choices such as exercise and dietary habits may potentially counteract those inflammatory changes related to higher ACE’s due to the anti-inflammatory properties associated with those choices. METHODS Participants visited the Exercise Physiology Lab and first completed an informed consent. Following that, participants were given the two survey instruments: ACE’s assessment and Simple 7 assessment. Participants were to complete each survey assessment and place the completed assessments in a sealed manilla envelope. After completing the survey instruments, participants had resting blood pressure, height, weight and body composition (Tanita body fat scale) measurements completed. Following the resting measures participants put on a Polar telemetry strap and started a self-selected warm-up on the treadmill. After a 5-min warm-up, participants started a Bruce Protocol treadmill test that was terminated at 80% of age-predicted maximum heart rate or a request to stop or for any reason signifying cardiopulmonary distress . A correlational analysis was conducted using SPSS v30. RESULTS In total12 participants (8 female, 4 male) were analyzed. Body mass index (BMI) and age of first occurrence for the ACE’s assessment were correlated, p = 0.045, r = -0.587. Other correlations were trending towards significance but due to a smaller sample size, significance was not achieved. ACE’s and stage RPE (p = 0.084, r = 0.519), heart rate at test termination (p = 0.054, r = 0.568) and resting arterial pulse pressure (p = 0.097, r = -0.502) were not significantly correlated. ACE’s assessment part 2 regarding support systems had a trending correlation with resting mean arterial pressure (p = 0.097, r = -0.501). CONCLUSIONS ACE’s may have a long-term physiological impact from psychological stress at a younger age. Data showed those with an earlier age of adverse experiences, correlated with a higher BMI. High BMI is associated with many chronic diseases such as heart disease, lung disease, metabolic diseases and cancer. With other data trending toward significance, further investigation into ACE’s and health values should be explored to determine the long-term impact of psychological damage from childhood.

Heart Rate Recovery after a 6-minute Walk test in Patients with Lower Extremity Artery Disease in Burkina Faso, sub-Saharan Africa

Background: Heart rate recovery (HRR) is a measure of fitness and an indication of cardiac health. The decrease in heart rate occurring immediately after exercise is caused by increased vagal activity and sympathetic withdrawal occurring after exercise.Objective: Our aim was to study the relationship between of the clinical severity of the lower limb artery disease (Fontaine classification) assessed during a 6-minute walking test and the decrease in heart rate (HR) from maximal exercise HR at 1-minute post-exercise (HRR1).Material and method: We studied patients were enrolled from January to December 2021 and screened in the vascular function exploration unit of the Souro SANOU University Hospitalof Bobo-Dioulasso, Burkina Faso, sub-Saharan Africa.Results: A total of 98 patients were included with a mean age of 53.6 ± 11.2 years, predominantly female (60.2%). The mean values were:0.834 ± 0.16 for ABI, 77± 11 bpm for resting HR, 108 ± 14bpm for end-exercise HR, 15bpm ± 8bpm for HRR1, 296± 95 m for maximum walking distance. Among the groups of the Fontaine classification, group IV walked the least (224±115m) and had the smallest HRR1 (11±8 bpm). Conclusion: Our study showed a significant relationship between HRR1 after a 6-minute walk test and the severity of lower limb ischemia. This could potentially lead to better peripheral arterial disease management strategies based on post-exercise cardiac recovery.

Low-level auricular vagus nerve stimulation lowers blood pressure and heart rate in paroxysmal atrial fibrillation patients: a self-controlled study

ObjectiveTo investigate the effects of low-level auricular vagus nerve stimulation (LL-aVNS) on blood pressure and heart rate in patients with paroxysmal atrial fibrillation.MethodsA total of 22 patients with paroxysmal atrial fibrillation diagnosed in Fuzhou First General Hospital Affiliated with Fujian Medical University from September 2021 to December 2022 were selected and given LL-aVNS treatment based on the original unchanged drug treatment for 4 weeks. The systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate maximum (HRmax), heart rate minimum (HRmin), left ventricular ejection fraction (LVEF), left atrial diameter (LAD), Atrial Fibrillation Severity Scale (AFSS) symptom subscale, and Memorial Symptom Assessment Scale-Heart Failure (MSAS-HF) before and after the treatment were observed and compared. In addition, adverse effects of the LL-aVNS procedure and 6-month follow-up were recorded.ResultsSBP, DBP, and HRmin were lower after the treatment than before the treatment (p &amp;lt; 0.05); AFSS symptom subscale scores and MSAS-HF scores after the treatment were lower before the treatment (p &amp;lt; 0.05); itching of the skin was observed in one case during the course of LL-aVNS; and two patients were hospitalized for acute exacerbation of chronic heart failure between 4 months and 6 months after the treatment.ConclusionLL-aVNS in patients with paroxysmal atrial fibrillation can assist in controlling blood pressure and heart rate, effectively relieving symptoms, and the treatment process is safe and feasible.

Exploring stress echocardiography in coronary artery disease: insights from a tertiary echocardiography center

Abstract Background/ Introduction Stress echocardiography (SE) is an established functional test with high sensitivity and specificity for diagnosing obstructive coronary artery disease (CAD). Purpose The present study aimed to document the experience of a tertiary hospital’s echocardiography center in using dynamic echocardiography to assess myocardial ischemia. Methods The study was performed retrospectively, including all patients who underwent SE at our center from January 2021 to December 2021. The goal for each test was to reach 85% of the age-predicted maximal heart rate (HR) (220 minus the subject’s age). The adopted Dobutamine stress protocol involved a continuous intravenous infusion of Dobutamine in 3-minute increments, starting at 10μg/kg/min and gradually increasing to 50μg/kg/min. Handgrip exercises were typically used, along with a small dose of intravenous atropine (0.25mg, up to a maximum of 1 mg) if the endpoint was not reached. Parasternal and apical echocardiographic views were obtained at all stages, and a contrast agent was used when appropriate. All tests were conducted under continuous 12-lead electrocardiographic (ECG) monitoring. Results Out of the 323 subjects [mean age 63.5 ± 10.5 years, 221 males (68.4%)], 123 (38.0%) underwent testing due to suspected CAD symptoms, while the remaining subjects (200 / 62.0%) were tested to reassess known CAD (with or without previous intervention). Twenty-one (7.0%) subjects had a left ventricular ejection fraction (LVEF) ≤40% at rest. The maximum dose of dobutamine most commonly administered was 30 μg/kg/min [137 subjects, (43.0%)], and atropine was given in 51 subjects (16.0%). The target HR was achieved in 291 (90.0%) tests. Eighty-seven (27.0%) SEs utilized a contrast agent in all stages, while in 177 (55.0%) a contrast agent was administered only at rest and peak HR. Major complications, such as acute myocardial infarction or persistent ventricular tachycardia, occurred in 6 patients (1.8%). Specifically, 5 (1.5%) experienced transient ST-segment elevation during the test, and one patient had a lateral myocardial infarction with ST-segment elevation after the test. No allergic reactions were reported. In 226 (70.0%) tests, results were classified as "negative for ischemia up to the achieved HR". In the remaining tests, classified as "positive for ischemia" (97/30.0%), the mean wall motion score index (WMSI) at peak HR was 1.3 ± 0.2 with a mean peak-to-rest ΔWMSI of 0.1 ± 0.1 (Table 1). Conclusion Of all the SEs performed at our center with an indication for assessing myocardial ischemia, 30.0% were positive, while major complications occurred in 1.8% of the subjects.

Detection of ischemia in kidney transplant candidates: is pharmacological stress echocardiography essential?

Abstract Introduction and Objectives The increase in the average age of candidates for kidney transplantation (KT) implies a higher number of comorbidities and cardiovascular risk (CVR). Pharmacological stress echocardiography (SE) is frequently preferred over exercise to assess pre-surgical CVR in these patients. However, this preference is based on the assumption that they have poorer functional capacity, which is not sufficiently supported by scientific evidence. The objective of this study is to determine the cardiovascular risk profile of kidney transplant candidates and the utility of exercise echocardiography (EE) for risk stratification and predicting complications arising from the transplant. Methods Retrospective analysis of patients referred to Cardiology for pre-KT evaluation following our local protocol, between January 2021 and December 2023. EE was preferably performed if the patient had adequate ambulation capacity, using a treadmill with the Bruce protocol to maximum capacity, setting the target heart rate at 85% of the theoretical maximum heart rate (TMHR, 220-age). Functional capacity was measured in exercise time (ET) and metabolic equivalents (METs). SE was performed with dobutamine or dipyridamole. Results Forty-six patients with advanced renal failure were included, 63% on renal replacement therapy (RRT), with a mean age of 66± 11 years and 76.1% male. In 70% of the patients, EE was initially performed, with 13 studies (34%) being inconclusive due to TMHR criteria, of which 8 subsequently required SE (17% of the total). The mean exercise time was 6.11± 2.9 minutes. The mean functional capacity was 6.8 ± 2.3 METs, slightly lower than predicted for sex and age (7.5 METs), but this difference was not significant (p=0.23). Among the SEs (30%), one study was performed with dipyridamole, and the rest with dobutamine, with complications such as non-sustained ventricular arrhythmias and arterial hypotension recorded in 2 SEs. Only one study was positive for inducible ischemia, for which a coronary angiography was performed without significant lesions. A total of 11 patients (24%) received KT, with no cardiovascular complications recorded during the perioperative period. Conclusions Patients with advanced renal failure or on RRT who are candidates for KT, despite their high CVR, have a low incidence of inducible ischemia and acceptable functional capacity. EE is a test that allows for cardiovascular risk assessment prior to the intervention in most patients, with fewer complications than SE. Baseline characteristics

All extern? Exploring the Impact of Social Media and Physical Activity on Adolescents’ Body Image and Interoception

Introduction Screen time among Swiss adolescents is rising, with one primary factor being their average daily smartphone use of up to four hours. A significant portion of this time is devoted to social media platforms such as TikTok, Snapchat, and Instagram (Külling et al., 2022). Due to substantial biological, cognitive, and social changes during this developmental phase, adolescents are highly sensitive to external stimuli. Following, adolescence is a crucial period in the development of one’s body image. Intriguingly, visually driven applications like Instagram seem to trigger adolescents’ sensitivity to external stimuli. Research confirms that frequent use of image-focused social media platforms negatively impacts adolescents’ body image (de Valle et al., 2021). However, besides external stimuli, the brain also processes information from within the body through a mechanism known as interoception, which involves sensing and interpreting internal bodily signals (Craig, 2003). Current theories posit a multisensory integration of exteroceptive and interoceptive signals in the formation of the body image. Interestingly, it is suggested that a higher interoception is related to a healthier body image (Badoud &amp; Tsakiris, 2017). Moreover, recent research has shown that the use of digital media is associated with a reduced perception of interoceptive signals. In contrast, acute physical activity has demonstrated its capacity to enhance both body image and interoception (Wallman-Jones et al., 2023), positioning it as a promising candidate for mitigating potential adverse effects of social media use. Therefore, this study aims to examine the effects of both social media exposure and physical activity on adolescents’ body image and interoception. Methods In a within-subject design, 36 participants aged 13 to 17 will take part in a laboratory experiment consisting of two experimental conditions. In the first condition, participants will engage in 15 minutes of Instagram use, during which they will be instructed to visit six different profiles of male or female fitness influencer of the same gender themselves. In the second condition, participants will cycle on an ergometer for 15 minutes. Intensities will be increased from light (50-63% of HR Max) to moderate (64-76% of HR Max) and vigorous (77-93% of HR Max). Interoceptive accuracy (Heartbeat Counting Task) and state positive body image (State Body Appreciation Scale, Body Functionality Scale) will be measured before and immediately after the experimental manipulations, Measurements will take place at a one-week interval. At baseline participants will fill out a questionnaire regarding interoceptive awareness, trait body image, smartphone use, and general physical activity. Subsequently, participants will perform a 20m-shuttle run test to assess physical fitness and maximal heart rate. These will be used to individualize the intensity of the physical activity. Results The study is currently ongoing, and results will be presented at the conference. The outlined study design enables an evaluation of the effects of acute social media use and physical activity on adolescents’ body image and interoception. The findings will contribute to a deeper understanding of how social media and physical activity influence adolescents’ body image and interoception, potentially guiding future interventions to promote healthy body perception in adolescents.

The effect of exercise on GDF-15 levels in individuals with prediabetes: A randomized controlled trial.

Growth differentiation factor-15 (GDF-15) is an inflammatory cytokine that increases in prediabetes and is known for its anorexigenic effects. This study aims to evaluate the effects of a 12-week exercise program on GDF-15 in individuals with prediabetes. In this multicenter, parallel-group, randomized-controlled trial, 64 patients aged 18-60 diagnosed with prediabetes were randomized in a 1:1 ratio into the exercise group (E) and the control group (C). Additionally, 32 patients who were planned to start metformin were included in the metformin group (M). Participants in the exercise group engaged in aerobic exercise at 50-70% of their maximum heart rate for 60 min, 3 days a week. Serum GDF-15 levels were evaluated at the beginning and the end of the 12th week. The mean age of the 91 participants who completed the study was 46.13 ± 8.52 years, and 23.1% were male. Basal GDF-15 levels were similar among the groups (E = 668.6 ± 415.1, C = 651.8 ± 352.5, M = 603.6 ± 387.2, P = 0.47). At the 12th week, GDF-15 levels were lower in the E compared to the C, while higher in the M compared to the C (E = 383.1 ± 215.6, C = 556.4 ± 285.6, M = 810.8 ± 498.0, P < 0.001). In inter-group comparisons, no significant change was observed in the C between the 0th and 12th weeks, while GDF-15 decreased in the E (P < 0.001) and increased in the M (P < 0.001). It was determined that in individuals with prediabetes, GDF-15, which serves both as a biomarker of metabolic disorder and has a negative regulatory effect on appetite, decreased with 12 weeks of aerobic exercise and increased with metformin administration.

The influence of exercise modality and intensity on ventricular arrhythmia burden and perception of effort in patients with Arrhythmogenic Right Ventricular Cardiomyopathy with plakophilin-2 variants

Introduction Intense endurance exercise is discouraged for patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), as it can increase the risk for adverse cardiac events as well as accelerate disease progression. While a sedentary lifestyle is also not advisable, there is currently no prospective data on the safety of physical activity for ARVC patients. To describe ARVC patients' average and peak ventricular arrhythmia burden – estimated from the prevalence of premature ventricular contractions (PVC) – measured during and after different exercise modalities and intensities, in context with cardiac and physiological load. Methods Twenty ARVC patients (8 f/12 m, age 48 ± 15 years, BMI 24 ± 3 kg/m2, resting PVC burden 4 ± 4%) with a heterozygous pathogenic/likely pathogenic plakophilin-2 (PKP-2) variant prospectively performed different exercises while monitored via 12-lead ECG. The order of modalities was randomized and participants were instructed to stop when surpassing perceived exertion of 15 (6-20 Borg scale). Resistance exercises included 2-min two-legged squats and single arm biceps curls (20 repetitions each) while endurance exercise included 5-min treadmill walking at comfortable speed and 3-min cycling bouts at a heart rate (HR) of 80, 100 and 120 bpm. Each activity was followed by a 10-min recovery period. Blood lactate concentration [La-] was assessed at the end of each cycling bout, with 4 mmol/L defined as a threshold to describe high-intensity exercise. Results No adverse events (including sustained ventricular tachyarrhythmia) nor premature terminations occurred. Average PVC burden during activities (including 5 min recovery) was lower for biceps curls compared with all other activities (p &lt; 0.046), despite having the second highest level of perceived effort (13.8 ± 1.7 units). Biceps curls elicited ~20 mmHg (p &lt; 0.001) lower peak systolic blood pressure and ~40 bpm peak lower HR (p &lt; 0.001) compared with cycling at 120 bpm, despite similar perception of effort (12.9 ± 1.7, p = 0.818). Peak PVC burden during the different activities (highest PVC count in 1 min) ranged between 0–57% among participants and it was lower during the activities (5 ± 8%) than the subsequent 5-min recovery (8 ± 8%, p = 0.006). but no differences were detected between activities. Five patients (25%) presented [La-] that exceeded 4.0 mmol/L when cycling at 120 bpm. Discussion/Conclusion PVC burden, a marker for arrhythmogenicity, was generally higher during recovery than during exercise, with the smallest burden found during the exercise with a small muscle mass, despite high perceived exertion. Thus, such exercises might be better suited for training in ARVC patients. Generalized recommendations for a maximum HR of 120 bpm during exercise likely predispose a high number of ARVC patients to inadvertently perform high-intensity exercise, risking accelerating disease progression. Therefore, individualized exercise prescription should be recommended.

A case report of the female world record holder 1500m to marathon in the 75+ age category.

Purpose: This study assessed the cardiorespiratory fitness, running biomechanics, muscle architecture and training characteristics of a 76-year-old female runner who currently holds the world record 1500m to marathon in the women's 75-79 age category. Methods: maximal oxygen uptake (V̇O2max), running economy (RE), lactate threshold (LT) and lactate turnpoint (LTP), maximal heart rate (HRmax), and running biomechanics were measured during a discontinuous treadmill protocol followed by a maximal incremental test. Muscle architecture was assessed using ultrasound. The testing was done in close proximity to her world record marathon performance in 2024. Results: V̇O2max was 47.9 ml∙kg-1∙min-1, and HRmax was 180 beats∙min-1. At marathon speed (11.9 km∙h-1) her RE was 210 ml∙kg-1.km-1. Fractional utilisation corresponding to LT (11.1 km∙h-1) and LTP (12.5 km∙h-1) occurred at 83% and 92% of V̇O2max, respectively. Fractional utilisation at marathon speed corresponded to 88% of V̇O2max. Average weekly distance was 115 and 84 km∙w-1 in the 6 weeks prior to the marathon world record and world-championships track (where she achieved 6 medals out of 6 events), respectively, with on average 90%, 9%, and 1% of training time performed in the moderate, heavy, and severe intensity domain, respectively. Conclusion: The 76-year-old female world-record holder 1500m to marathon showed the highest V̇O2max ever recorded for a female >75 years old, a very high fractional utilization of V̇O2max at LT, LTP, and at marathon pace, but RE was modest in comparison to other world-class master athletes and younger elite runners.

Exploring the Effects of Sleep Deprivation on Physical Performance: An EEG Study in the Context of High-Intensity Endurance

BackgroundWhile the effects of sleep deprivation on cognitive function are well-documented, its impact on high-intensity endurance performance and underlying neural mechanisms remains underexplored, especially in the context of search and rescue operations where both physical and mental performance are essential. This study examines the neurophysiological basis of sleep deprivation on high-intensity endurance using electroencephalography (EEG). In this crossover study, twenty firefighters were subjected to both sleep deprivation (SD) and normal sleep conditions, with each participant performing endurance treadmill exercise the following morning after each condition. EEG signals were recorded before and after high-intensity endurance exercise, and power spectrum analysis and functional connectivity analysis were performed on sleep related frequency bands rhythm: δ (0.5–4 Hz) and θ (4–8 Hz). The EEG power spectral and functional connectivity were measured by repeated measure analysis of variance.ResultsThe SD condition had an average sleep duration of 3.78 ± 0.69 h, while the duration for normal sleep was 7.63 ± 0.52 h. After high-intensity endurance exercise, the SD condition had a higher maximum heart rate (p < 0.05) and shorter exercise time (p < 0.05) than normal sleep. Compared with before exercise, the δ band in the left parietal lobe P7 channel increased significantly (p < 0.01), and the θ band in the central Cz channel and the left and right parietal lobe P7 and P8 channel increased significantly (p < 0.01 & p < 0 0.05) in SD and normal sleep conditions after exercise. After exercise, compared with normal sleep, the δ band power in occipital O1 and Oz channels and parietal P7 and TP7 channels in SD significantly decreased (p < 0.05 & p < 0.01); the power of the θ band decreased significantly in the occipital O1 channel, central CZ channel and the left and right parietal P7 and P8 channel (p < 0.05 & p < 0.01). Whole connectivity showed a significant increase (p = 0.001) in the δ band for the SD condition at post-exhaustion. Local connectivity analysis identified a localized network in the δ band with reduced (p < 0.001) post-exhaustion in the SD condition displaying inter-hemispheric differences in certain connections (FP1-CP4, T7-C4, T7-TP8, and O1-FT8) and intra-hemispheric (C3-CPz and Pz-P4) variations.ConclusionsSleep deprivation significantly reduced maximum endurance performance, indicating decreased neural activity in the central and parietal brain regions. Alterations in δ and θ frequency band power, along with disrupted connectivity, may highlight the neurophysiological basis underlying this decline.

Squash in Los Angeles: Heat Strain and Performance Considerations at the 2028 Olympic Games.

The Los Angeles 2028 Olympics will mark the debut of squash, a high-intensity sport characterized by repeated efforts, posing potential thermoregulatory challenges. The demanding nature of squash results in substantial metabolic heat production, with consequential heat strain exacerbated by the indoor environment of squash courts, where low to moderate evaporative potential limits effective cooling. Players often experience increased body-heat storage and thermal strain, with muscle cramps (an early warning sign of more severe heat-related illnesses) commonly observed during tournaments. Despite these challenges, there are limited data on the thermoregulatory responses of elite squash players during match play. We discuss the thermoregulatory challenges faced by squash players and highlight key areas for research. Additionally, practical guidelines are provided for practitioners preparing squash players for the Los Angeles 2028 Olympics. Preliminary findings from international squash tournaments reveal that elite players endure significant physiological strain, with core temperatures rising to 39.0 °C to 40.1 °C, despite matches being played in mild wet-bulb globe temperatures of 19.4 °C (0.9 °C). Sustained heart rates exceeding 90% of maximal heart rate further compound this thermal strain. However, research on how thermal strain affects squash-specific fitness, recovery, and stroke mechanics are lacking. Such information is crucial for evaluating the need and effectiveness of tailored mitigation strategies such as heat training/exposures and precooling and midcooling during warm-up and match play. Systematic research into the thermal demands of squash and their impact on fitness and skills is needed. These insights can inform evidence-based strategies to safeguard athlete well-being and optimize performance at Los Angeles 2028.

Progressive Training Program Improves Aerobic Capacity and Physical Fitness in Student Soccer Athletes

The endurance of soccer players in Indonesia is generally still low. Aerobic capacity is an important component for improving physical fitness and endurance. When comparing several age groups, young players have less physical fitness. This study aimed to determine the effects of progressive training on changes in the maximum oxygen volume (VO2max) and heart rate (HR) based on recovery time. This study is quasi-experimental with a control group design and was conducted on student soccer athletes. Sixty athlete students who met the inclusion criteria were divided into a control group (n=30) and a progressive training group (n=30). The intervention consisted of progressive training for ten weeks with marathon running at distances of 150, 200, and 300 meters with rest intervals for each distance. The training load was gradually increased by increasing the number of repetitions every week. VO2 max, and Heart Rate were evaluated before and after the program. The results shown that the VO2 max was significantly different between the groups (p&lt;0.001), and the Heart Rate of the subjects in both groups decreased from start to finish. Notably, the HR in the progressive training group was lower than the control group. In conclusion, progressive training is effective in improving aerobic capacity and physical fitness.

Effects of topical sodium bicarbonate emulsion on exercise exhaustion and training effects following high-intensity interval training in high-level soccer players

Background and Goal: High-level football players’ competitive performance and training efficacy are significantly impacted by sports weariness. Verifying the possible use of external sodium bicarbonate lotion in professional sports and investigating its effects on the training effect and sports fatigue of elite football players following high-intensity interval training (HIIT) are the goals of this study. Methods: 14 male football players competing at the national level were split into two groups, one experimental and one control, each consisting of seven participants. This study was conducted using a randomized double-blind controlled trial. Twenty min prior to training, the experimental group applied external sodium bicarbonate lotion, while the control group applied a placebo lotion. Group antagonistic training and a seven-day HIIT comprise the training regimen. Assess the effects of the intervention using a variety of multifaceted data, including exercise performance, training impact intensity (TRIMP), delayed onset muscle soreness (DOMS), subjective tiredness scale, perceived fatigue level (RPE), blood biochemical indicators, and heart rate monitoring. Result: Following a single HIIT training session, the experimental group’s blood lactate level was significantly lower than the control group’s (P &lt; 0.05); however, no other indicators showed any significant changes. The experimental group’s TRIMP values were considerably greater than the control group’s during the seven-day training period, and their average DOMS and RPE values were significantly lower (P &lt; 0.05). Maximum heart rate and anaerobic training effect were statistically significant (P &lt; 0.05), and the experimental group outperformed the control group in terms of maximum EPOC, maximum heart rate, anaerobic training effect, and energy consumption. In conclusion, applying sodium bicarbonate lotion externally can improve athletes’ overall performance, increase training stimulus, and considerably lessen muscle soreness and exercise fatigue during high-intensity interval training.

Eight weeks of aerobic exercise, but not four, improves insulin sensitivity and cardiovascular performance in young women

Regular aerobic exercise has a significant impact on glucose metabolism and lipid profiles, contributing to overall health improvement. However, evidence for optimal exercise duration to achieve these effects is limited. This study aims to explore the effects of 4 and 8 weeks of moderate-intensity aerobic exercise on glucose metabolism, lipid profiles, and associated metabolic changes in young female students with insulin resistance and varying body mass, seeking to determine the optimal duration for physiological adaptations. Twenty-eight physically semi-active female students were randomly assigned to 4-week (G4, n = 13, age = 23.31 ± 5.19, BMI = 24.78 ± 5.87) and 8-week (G8, n = 15, age = 21.8 ± 2.56, BMI = 24.95 ± 4.81) training groups. The aerobic intervention maintained an intensity of 40–70% of maximum heart rate (HRmax). 6-min-walk test (6MWT), handgrip strength tests, insulin, HOMA-IR, lipid profiles, and metabolic profiles were assessed pre- and post-intervention. Following the intervention, G8, but not G4, exhibited a significant decrease in HOMA-IR (-14.59%, p = 0.047). The improvement in HOMA-IR was accompanied by notable improvements in 6-MWT (+ 38.18%, p < 0.001) and handgrip strength (+ 11.62, p = 0.027 and + 17.59%, p = 0.013), and increased levels of bilirubin degradation products, ribose, and glutarate. The elevated levels of bilirubin degradation products, known for their antioxidant properties, suggested a potential antioxidative response triggered by prolonged aerobic exercise. Additionally, an increase in ribose and glutarate indicated improved metabolic flexibility and enhanced utilization of alternative energy substrates. The 8-week aerobic exercise regimen demonstrated enhanced insulin sensitivity, upper body strength, and cardiovascular performance in young females compared to a 4-week regimen by triggering specific metabolic adaptations. These findings emphasize the complex relationship between exercise duration, metabolic adaptations, and overall well-being in young women, providing valuable insights for optimizing exercise prescriptions in promoting metabolic health.