Maximal Heart Rate Research Articles

Effect of Right Nostril Breathing on Cardiorespiratory Parameters and Reaction Time in Young, Healthy Humans: An Interventional Study.

Yogic breathing helps in reduction of stress and strain in the body. Right and left nostril breathings (RNB and LNB, respectively) have different effects on cardiorespiratory parameters. The study was performed to examine the effect of RNB exercise on cardiorespiratory parameters and reaction time in young, healthy human volunteers. In this prospective, interventional study, 110 young healthy volunteers underwent systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse rate (PR), respiratory rate (RR), vital capacity (VC), peak expiratory flow rate (PEFR), and reaction time (RT) examination before and after 2 weeks of performing 45 min of RNB exercise daily. There was notable increment in SBP (113.39 ± 17.72 vs. 117.74 ± 10.83 mmHg, P = 0.002) and DBP (67.64 ± 10.32 vs. 71.27 ± 8.68 mmHg, P = 0.002). PR increased nonsignificantly (86.44 ± 12.65/min vs. 87.32 ± 13.43/min, P = 0.476). Significant decrease in RR (14.40 ± 2.48/min vs. 12.31 ± 2.23/min, P < 0.0001) was observed. VC (3.57 ± 0.57 vs. 3.82 ± 0.55 L/min, P < 0.0001) and PEFR (441.36 ± 50.22 vs. 468.91 ± 53.66 L/min, P < 0.0001) also increased significantly. Substantial reduction in auditory reaction time (ART) (165.58 ± 32.18 vs. 147.42 ± 23.39 ms, P < 0.0001) and visual reaction time (VRT) (191.04 ± 37.94 vs. 165.86 ± 28.74 ms, P < 0.0001) was seen. After engaging in cardiorespiratory exercise, the maximal heart rate (MHR) remained unchanged (P = 0.929). RNB results in increase in blood pressure, heart rate, VC, and PEFR and decrease in ART and VRT. Further studies in patients with cardiorespiratory diseases are necessary to understand its clinical utility.

Todas as Provas de Esforço Devem Ser Limitadas por Sintomas e não por se Atingir 85% da Frequência Cardíaca Teórica

Except for situations of acute myocardial infarction before hospital discharge, the exercise test should always be limited by symptoms, signs or exhaustive muscle fatigue and not by reaching 85% of the maximum theoretical heart rate. One of the objectives of the test is to reproduce symptoms and evaluate whether, simultaneously or not, signs of reversible ischemia appear on stress ECG, changes in rhythm or blood pressure, which presupposes not performing submaximal tests. A submaximal test does not allow maximum aerobic capacity calculation, an important prognostic factor whether in asymptomatic individuals or patients with ischemic heart disease. The greater adrenergic stimulation caused by high intensity effort, especially when the maximum aerobic capacity has been exceeded, can be decisive for the induction of potentially malignant arrhythmias when the aim is to stratify risk in certain heart diseases.

Feasibility Study of Exergaming Combined with High-Intensity Interval Training for Different Ages: Investigation of Aerobic Capacity and Mood State

&lt;p&gt;目的：探討體感式電玩結合高強度間歇運動對不同年齡層之血乳酸、心跳率、運動負荷量與運動情緒之效果。方法：本研究以有規律運動習慣之8位成年人與8位高齡者為研究對象，採橫斷面研究設計，並執行以任天堂switch健身環大冒險遊戲所設計之運動，進行8組20秒，強度為盡最大努力，每組間隔休息30秒，總時間為380秒。於運動前、運動中與運動後5分鐘、10分鐘檢測血乳酸、心跳率、運動自覺量表與運動情緒，計算運動負荷量，並以二因子混合設計分析收集數據，並計算效果量。結果：1. 血乳酸：兩組的血乳酸皆超過4 mmol/L，顯示運動強度達高強度，且成年人在運動中第4、8趟與運動後5、10分鐘皆顯著高於高齡者；2. 心跳率：運動期間，兩組的心跳率皆超過85%最大心跳率推估值，而成年人顯著高於高齡者；3. 運動負荷量：兩組間客觀與主觀的運動負荷量皆無顯著差異；4. 運動情緒：兩組在運動情緒之活力與疲勞分數上皆無顯著差異。結論：成年人和高齡者皆可利用體感式電玩搭配高強度間歇運動達到預期的高強度運動負荷，故可作為運動課程編排參考，以達到運動多元化。&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;p&gt;Purpose: This study aimed to investigate the effects of combining exergaming with high-intensity interval exercise (HIIE) on blood lactate levels, heart rate, exercise load, and mood state in different age groups. Methods: A cross-sectional study design was employed, and 8 young adults and 8 older adults, all with regular exercise habits, were recruited. The participants executed a HIIE program using the Nintendo Switch fitness ring adventure, comprising 8 sets of 20-second maximum-effort intervals followed by 30 second of rest, totaling 380 seconds of exercise. Blood lactate levels, heart rate, rating of perceived exertion (RPE) scale, and profile of mood states (POMS) were assessed before, during, and 5 and 10 minutes after the exercise. Exercise load was calculated based on the collected data. The data were analyzed using a two-way mixed-design analysis of variance. Results: 1. Blood lactate levels: The concentration of blood lactate in both groups showed an increase over 4 mmol/L during HIIE program, indicating the high exercise intensity. The young adult group exhibited significantly higher blood lactate levels than the older adult group at the 4th, 8th exercise bouts, and 5 and 10 minutes after exercise. 2. Heart rate: During the exercise, heart rates of both groups exceeded 85% of the estimated maximum heart rate (HRmax), with significantly higher rates observed in the young adult group compared to the older adult group. 3. Exercise load: There were no significant differences in objective (%HRmax) and subjective (RPE scores) exercise load between the groups. 4. Mood state: Both groups showed no significant differences in vigor and fatigue scores on the POMS. Conclusion: To diversify exercise options, combining exergaming with HIIE when designing an exercise program could be an option in both young and older individuals.&lt;/p&gt; &lt;p&gt;&amp;nbsp;&lt;/p&gt;

Effect of interactive exergame training on physical fitness and executive function among men with substance use disorder in rehabilitation center

BackgroundSubstance use disorder (SUD) is a chronic disease characterized by drug seeking and use that is compulsive or difficult to control despite harmful consequences. Researchers have found treatments to help people recover from SUD and lead productive lives. Exercise therapies have been approved to be effective on executive function, physical fitness, and cravings in men with SUD. Exergaming, which involves physical activity through interactive video games, has attracted considerable interest due to its ability to provide a fun and engaging aerobic workout while stimulating cognitive functions. However, despite its popularity in recreational settings and its potential to promote physical fitness and cognitive well-being, the use of exergaming as a therapeutic modality for SUD remains relatively underexplored. This study aimed to investigate the effects of exergame on physical fitness and executive function in men with SUD. MethodsThe 44 compulsory men in a rehabilitation center (mean age = 39.7 ± 9.2 years) were divided to either an exergame training (ET) or a control group. The ET group underwent a moderate-intensity (65%–75% of maximum heart rate) exergame training intervention (Fitness Boxing 2 & Super Mario Party) for 50 min thrice weekly during a 12-week period. The control group maintained their original lifestyle in the rehabilitation center. Before and after the intervention, participants were evaluated for drug craving, executive function (working memory and attention bias), and physical fitness (blood biochemical, choice reaction time, and BMI et al.). ResultsThe exergame training group showed a significantly positive effect in drug craving and attention bias score, relative to the control group (drug craving: F = 4.374, p = 0.043, d = − 0.51; attention bias score: F = 4.832, p = 0.034, d = − 0.357). No significant effect has been found in other variables (p > 0.05). ConclusionThe 12-week interactive exergame training can effectively reduce drug craving and improve executive function in men with SUD in drug rehabilitation centers. This training may offer a new and alternative exercise treatment against SUD. Exercise treatment approaches tailored to men with SUD may lead to continued recovery in health and lower the risk of returning to substance use.

The Effect of Hypoxic Exercise Combined with Crocodile Blood Supplementation on Aerobic Capacity and Hematological Variables in Athletes

Study purpose. This study aimed to compare the effects of hypoxic exercise combined with crocodile blood supplementation on hematological and maximum oxygen consumption parameters in soccer players. Materials and methods. This study included 39 male soccer players aged 21.69 ± 1.98 years who were randomized to three groups. All groups performed the same training program, which comprised treadmill exercise at 70%–75% of maximum heart rate for 7 weeks with sessions of 30 min/day and 3 days per week. The first group was the control placebo group (CG, n = 13), the second group received one capsule per day (60 mg) of a freeze-dried crocodile blood supplement (SUP, n = 13), and the third group received the freeze-dried crocodile blood supplement and performed the training program under hypoxic conditions (H-SUP, n = 13, FiO2 = 16.3%). A hematological evaluation was conducted and maximal oxygen uptake (VO2max) was measured using the Bruce protocol treadmill test. Results. The H-SUP group demonstrated significantly higher erythropoietin (EPO) levels (14.40 ± 2.41 mIU/mL) compared to the SUP group (11.50 ± 2.08 mIU/mL) and CG (12.01 mIU/mL) after the intervention. From pre- to post-intervention, VO2max significantly increased in the H-SUP (Pre: 45.63 ± 4.75, Post: 49.33 ± 5.81) and SUP groups (Pre: 44.59 ± 4.75, Post: 47.30 ± 5.68) but not in the CG. Conclusions. This study reveals that a combination of freeze-dried crocodile blood supplementation and hypoxic exercise causes hematological alterations, particularly the activation of EPO secretion, and increases VO2max in soccer players.

Use of the Buffalo Concussion Treadmill Test in community adult patients with mild traumatic brain injury.

The Buffalo Concussion Treadmill Test (BCTT) is used to establish exercise tolerance for rehabilitation and identify injury subtypes for youth athletes after mild traumatic brain injury (mTBI). Its utility in adult community members is unknown. Primary: To describe how adults with and without mTBI tolerate the BCTT. Secondary: To explore relationships between baseline factors, mTBI-related symptoms, and BCTT duration. Prospective, observational, longitudinal. Academic medical center. Thirty-seven adults treated in a level 1 trauma center emergency department with mTBI; 24 uninjured controls (UC). N/A. Participants completed two visits 3 weeks apart (1 week and 1 month after mTBI) including a 15-minute BCTT, the Rivermead Post Concussion Symptoms Questionnaire (RPQ), and preinjury International Physical Activity Questionnaire. Analyses characterized BCTT response and associations between baseline factors, RPQ scores, and BCTT duration. Persons with mTBI discontinued earlier than UC at 1-week postinjury using standard discontinuation criteria for exercise intolerance. The percentage of mTBI participants with signs of possible mTBI-related intolerance was 55.6% at 1 week (36.1% for mTBI-related symptom exacerbation, 19.4% for exertion/fatigue before reaching 85% of one's age-predicted maximum heart rate [HR]) and 48.0% at 1 month (40.0% mTBI-related symptom exacerbation, 8.0% exertion without reaching the target HR). Thirty percent of UCs completed the BCTT at both assessments. UCs met discontinuation criteria for increased nonspecific symptoms (eg, pain/general discomfort and increased Visual Analog Scale ratings; 39-61%) and physical exertion (9-26%). Shorter duration was associated with higher body mass index (r = -0.42 - -0.45), shorter height (r = 0.22-0.29), female gender (r = -0.26 - -0.27), and greater RPQ symptoms (r = -0.28 - -0.47). The BCTT exacerbates mTBI-related symptoms in adult community members. Participant characteristics and noninjury factors influence performance. The findings imply the BCTT could be useful in clinical assessments of adults with mTBI. Interpretation should account for the unique characteristics of nonathletes.

Нарушения сердечного ритма и профиль артериального давления у пациентов с боевыми травмами

Aim. To investigate possible rhythm and conduction disturbances, as well as the blood pressure (BP) profile in young and middle-aged patients with combat wounds. Materials and methods. The cross-sectional study enrolled 102 patients who suffered limb injuries in the period from 13 to 114 days (median 38 days) before admission to the hospital. The age of the patients included in the study ranged from 20 to 59 years, with an average of 35.7±8.5 years. Patients underwent Holter ECG monitoring and 24-hour BP monitoring. The following questionnaires and scales were used: a questionnaire to identify signs of autonomic changes (A. Vein), a scale for assessing the severity of psychophysiological response to stress, an insomnia severity index, the Hamilton scale for assessing anxiety, the Hamilton scale for assessing depression, a questionnaire for PTSD screening, visual analog pain scale. Results. The mean heart rate per day reached 84.6±11.1 per minute, the minimum heart rate was 56.9±10.1, the maximum heart rate was 134.4±18.6 per minute. The group mean duration of tachycardia was 498.1±316 minutes (8 hours 18 minutes). There was an inverse correlation between the age of patients and the duration of tachycardia per day (r=-0.29; p=0.04), maximum heart rate (r=-0.28; p=0.007), minimum heart rate per day (r=-0.23; p=0.02). In patients 20-29 years old, the maximum heart rate reached 141.4±19.4, in patients over 40 years old – 134.3±17.9 (p=0.009). The mean value of the circadian index for the group was 1.17±0.13 (0.68-1.47). In 69.7%, the circadian index was rigid. Heart rate variability was within normal values in 32.2% of the examined patients, in 48.8% it was reduced, and in 19.1% it was sharply reduced. Heart rhythm disturbances were recorded in 65.5% of patients. The most frequently detected sinus arrhythmia (in 76.2% of cases of all arrhythmias), migration of the supraventricular pacemaker (in 27.0%) and atrial rhythm (in 11.1%). Arterial hypertension was detected in 67.7% of the examined patients. The maximum systolic BP (SBP) corresponding to arterial hypertension of the 1st degree was registered in 43.9% of patients, grade 2 – in 19.7%, grade 3 – in 3.0%, high normal BP – in 16.7%, normal BP – in 16.7%. Maximum diastolic BP (DBP) corresponding to grade 1 hypertension was found in 30.8% of patients, grade 2 – in 30.8%, grade 3 – in 15.4%, high normal BP – in 10.8%, normal BP – in 12.3%. The mean daily SBP was 126 mm Hg, DBP was 81 mm Hg. The mean daytime SBP was 128 mm Hg, DBP was 82 mm Hg. The mean nighttime SBP is 118 mm Hg, DBP is 77 mm Hg. The maximum SBP was 148 mm Hg, DBP was 97 mm Hg. When analyzing the types of daily BP curves, the vast majority of patients (44.6%) were classified as “non-dipper” type, both for SBP and DBP. Conclusions. The study results indicate that patients with combat injuries very often have sinus tachycardia, which is recorded over a long period of time. Heart rate is highest in the youngest injured patients and decreases as age increases. Sinus arrhythmia is very common, other rhythm and conduction disorders are much less common. High BP, especially DBP, is often recorded.

Circadian regulation of sinoatrial nodal cell pacemaking function: Dissecting the roles of autonomic control, body temperature, and local circadian rhythmicity.

Strong circadian (~24h) rhythms in heart rate (HR) are critical for flexible regulation of cardiac pacemaking function throughout the day. While this circadian flexibility in HR is sustained in diverse conditions, it declines with age, accompanied by reduced maximal HR performance. The intricate regulation of circadian HR involves the orchestration of the autonomic nervous system (ANS), circadian rhythms of body temperature (CRBT), and local circadian rhythmicity (LCR), which has not been fully understood. Here, we developed a mathematical model describing ANS, CRBT, and LCR in sinoatrial nodal cells (SANC) that accurately captures distinct circadian patterns in adult and aged mice. Our model underscores how the alliance among ANS, CRBT, and LCR achieves circadian flexibility to cover a wide range of firing rates in SANC, performance to achieve maximal firing rates, while preserving robustness to generate rhythmic firing patterns irrespective of external conditions. Specifically, while ANS dominates in promoting SANC flexibility and performance, CRBT and LCR act as primary and secondary boosters, respectively, to further enhance SANC flexibility and performance. Disruption of this alliance with age results in impaired SANC flexibility and performance, but not robustness. This unexpected outcome is primarily attributed to the age-related reduction in parasympathetic activities, which maintains SANC robustness while compromising flexibility. Our work sheds light on the critical alliance of ANS, CRBT, and LCR in regulating time-of-day cardiac pacemaking function and dysfunction, offering insights into novel therapeutic targets for the prevention and treatment of cardiac arrhythmias.

Comparison of the Effect of Eight Weeks Aerobic and Combined Exercise on Some Hemodynamic Indicators in Middle-Aged Male Patients Undergoing Coronary Artery Bypass Graft Surgery

Introduction: Exercise training by modulating blood pressure and heart rate have a protective role for middle-aged cardiac patients. Aim of this study was to compare the effect of eight weeks of aerobic and combined exercise on some hemodynamic indicators in middle-aged male patients undergoing coronary artery bypass graft surgery.&#x0D; Methods: In this clinical trial, a sample of 30 middle-aged men who underwent coronary artery surgery in 2023 were enrolled after meeting predetermined eligibility criteria and randomized for participation. They were divided into three aerobic (n=10), combined (n=10) and control (n=10) groups. The individuals of the 2 intervention groups performed selected aerobic and combined exercises (with an intensity of 55 - 75% of the maximum heart rate, for 60 minutes) for 8 weeks, 3 sessions per week. Blood pressure, heart rate and peripheral oxygen saturation (SpO2) were measured before and after the intervention. The parametric paired sample t-test, one-way ANOVA test and Tukey's Test were used to examine differences at a significance level of P ≤ 0.05.&#x0D; Results: The effect of aerobic exercises on systolic blood pressure (P=0.036), diastolic blood pressure (P=0.040) and heart rate (P=0.013) was significant and caused a decrease in these indicators, but the decrease in the combined group was not significant (P&gt;0.05). The intergroup effect difference was not significant (P&gt;0.05). In both aerobic (P=0.000) and combined (P=0.007) groups, the peripheral oxygen saturation has increased significantly and intergroup mean difference was significant (P=0.004).&#x0D; Conclusion: It seems that aerobic and combined exercises as a helpful intervention strategy to improve hemodynamic indicators, make the patient more adaptable to the conditions after coronary artery bypass graft surgery.

Energy System Contributions in Repeated Sprint Tests: Protocol and Sex Comparison.

The aim of this study was to investigate the energy system contributions to different repeated sprint protocols and also to determine sex-related differences in these contributions. Sixteen men and fourteen women team sport athletes randomly performed two cycling repeated sprint protocols with the same total duration (10 x 6 s and 6 x 10 s). Relative peak power (RPP), relative mean power (RMP), performance decrement (PD), oxygen uptake (VO2), blood lactate (LA), heart rate (HR) and ratings of perceived exertion (RPEs) were measured. The contributions of energy systems were calculated from oxygen consumption and lactate values during rest, exercise and recovery phases based on mathematical methods. Findings indicate that men had higher RPP and RMP. RPP did not differ according to protocols, while RMP was higher in the 10 x 6 s protocol. The sex effect in PD was similar; however, it was higher in the 6 x 10 s protocol. The effects of protocols on the maximum HR and LA were similar; however, the 6 x 10 s protocol resulted in higher RPEs. In both protocols women had higher ATP-PCr and men had higher glycolytic system contribution with similar oxidative system contribution. In addition, the 10 x 6 s protocol had higher ATP-PCr system contribution and the 6 x 10 s protocol had higher glycolytic system and oxidative system contributions. In conclusion, the contribution of energy systems, physiological and performance variables showed variations according to sex and different protocols.

Impact of a short-term nitrate and citrulline co-supplementation on sport performance in elite rowers: a randomized, double-blind, placebo-controlled crossover trial.

Citrulline (CIT) and beetroot extract (BR) have separately shown benefits in rowing performance-related outcomes. However, effects of combined supplementation remain to be elucidated. The main purpose of this research was to study the effects of 1week of daily co-supplementation of 3.5g BR (500mg NO3-) plus 6g CIT on aerobic performance, maximal strength, and high-intensity power and peak stroke in elite male rowers compared to a placebo and to a BR supplementation. 20 elite rowers participated in this randomized, double-blind, placebo-controlled crossover trial completing 1week of supplementation in each group of study: Placebo group (PLAG); BR group (BRG); and BR + CIT group (BR-CITG). 3 main physical tests were performed: aerobic performance, Wingate test and CMJ jump, and metabolic biomarkers and physiological outcomes were collected. The Wingate all-out test showed no between-condition differences in peak power, mean power, relative power, or fatigue index (P > 0.05), but clearance of lactate was better in BR-CITG (P < 0.05). In the performance test, peak power differed only between PLAG and BR-CITG (P = 0.036), while VO2peak and maximum heart rate remained similar. CMJ jumping test results showed no between-condition differences, and blood samples were consistent (P > 0.200). Supplementation with 3.5g of BR extract plus 6g of CIT for 7days improved lactate clearance after Wingate test and peak power in a performance test. No further improvements were found, suggesting longer period of supplementation might be needed to show greater benefits.

The Effect of Nordic Walking on the Galectin 3 and Some New Metabolic Markers in Elderly Men with Osteosarcopenic Obesity

Background: Sarcopenia is the age-related progressive loss of muscle mass and strength. The main symptom of the condition is muscle weakness. Objectives: The aim of the present study was to determine the effect of 12 weeks of Nordic walking on the expression of the cardiovascular biomarker galectin 3 gene and some new metabolic markers in elderly men with osteosarcopenic obesity. Methods: Twenty elderly men with a Mean age of 60 to 80 years, who had osteosarcopenic obesity with a body mass index (equal to and above 30) and body fat percentage (equal to and above 30) participated in this research and they were randomly divided into 2 Nordic walking training groups and a control group (10 people in each group). The Nordic walking training program was implemented for 12 weeks and 3 days a week. The intensity of the exercises in each session was 50 to 75% of the maximum heart rate and the duration of each exercise session was 60 minutes. Results: 12 weeks of Nordic walking exercises caused a significant decrease in the circulating levels of galectin-3 (P = 0.001) and a decrease in the TyG-BMI index (P = 0.001) in the subjects. But there was no significant effect on the atherogenic index of plasma (AIP) (P = 0.265) and TyG (P = 0.126) and TyG-BMI (P = 0.347) indices of the subjects. Conclusions: Nordic walking exercise plays an important role in reducing cardiovascular risks by reducing galectin 3 biomarker and atherogenic plasma index (AIP).

Full Familiarisation Is Not Required for the Self-Paced 1 km Treadmill Walk to Predict Peak Oxygen Uptake in Phase IV Cardiac Patients.

Exercise is a recommended part of phase IV cardiovascular rehabilitation (CR). The 1 km treadmill walk test (1-KTWT) is a submaximal continuous exercise test to predict cardiorespiratory fitness in patients with cardiovascular disease. We examined physiological, metabolic and subjective responses in patients with cardiovascular disease with self-selected, unchanging walking speed for two 1-KTWTs. Fifteen men (age: 65 ± 9 yr, height: 174 ± 5 cm, body mass: 86 ± 17 kg, BMI: 28.5 ± 5.5 kg·m-2, body fat%: 27.7 ± 7.5%, 10 on beta-blockers) were recruited from phase IV CR groups in the United Kingdom. Participants established a self-selected walking speed for the 1-KTWT and performed the 1-KTWT on separate days with recording of physiological responses to predict V˙O2peak with equations. For the two 1-KTWTs, no differences existed for walking speed, mean and maximal heart rates, oxygen uptake, predicted V˙O2peak (1st 1-KTWT (range: 41-78% V˙O2peak, 95%CI, 53-65; 2nd 1-KTWT range: 43-78% V˙O2peak, 95%CI, 52-65) and rating of perceived exertion. In phase IV cardiac patients, the 1-KTWT with self-selected, unchanging walking speed can be used for V˙O2peak prediction without the need for a full familiarisation. The self-selected constant walking speed for the first 1-KTWT can be used to support nonsupervised physical activity for phase IV CR patients.

It’s not just the heart: respiratory limitations to constant-load exercise in adult Fontan patients and potential implications for rehabilitation

Introduction Congenital heart defects may require surgical intervention such as the Fontan procedure that connects the systemic venous return to the pulmonary arteries. Although this procedure has increased survival, it results in reduced exercise capacity; which is reduced not only due to cardiovascular factors, but respiratory limitations as well. However, there is a lack of evidence outlining ventilatory limitations during constant-load exercise, which better represents exercise in cardiac rehabilitation programs and non-laboratory based exercise. Therefore, the aim of the present study was to compare responses to constant-load exercise in adult Fontan patients with those of healthy well-matched controls. Methods 14 adult Fontan patients (5F, 27 ± 6yrs) were recruited with 14 healthy matched controls. Participants performed forced vital capacity (FVC), as well as maximal inspiratory and and expiratory pressure assessments (MIP and MEP, respectively). Patients performed an incremental cycling test (ICT) to exhaustion to determine peak work rate. Following a period of recovery, patients performed a constant-load cycling test (CLCT) at 70% of peak ICT work rate until exhaustion. Healthy subjects reproduced the exercise of their matched patient. Cardiorespiratory variables and heart rate (HR) were measured using a metabolic cart and a 12-lead electrocardiogram, respectively. Participants were asked to rate their perception of breathlessness and respiratory exertion via a visual analogue scale every 2 min and at peak exercise. Patients without cardiac pacemakers underwent involuntary assessments of respiratory muscle contractility via phrenic (n = 8) nerve magnetic stimulation before and following exercise to quantify respiratory muscle fatigue. Results Patients showed significantly reduced FVC, MIP and MEP compared to controls (all p &lt; 0.025). Patients’ time-to-exhaustion during the CLCT was 7.1 ± 3.3 min. During CLCT vs. the ICT, patients reached maximal HR, respiratory rate (fR), breathlessness, respiratory exertion, and leg exertion. End-exercise V̇O2 during the CLCT did not reach ICT values, with a mean difference of 1.5 ml/kg/min (p = 0.017). Controls did not reach peak ICT responses during the CLCT. During the CLCT, patients displayed significantly elevated minute ventilation (V̇E; mean difference = 21.5 L/min), fR (mean difference = 13.8 breaths-per-minute), breathlessness (mean difference = 3.4 points), and respiratory exertion (mean difference = 2.3 points), along with significantly decreased ventilatory reserve (V̇E/maximal voluntary ventilation; mean difference = 27.5%; all p &lt; 0.002). Following the CLCT, Fontan patients showed a larger decrease in involuntary respiratory muscle contractility (15 ± 12% vs. 2 ± 11%). Finally, a decreased ventilatory reserve was significantly correlated with decreased MIP (r = 0.723, p = 0.003) and MEP (r = 0.623, p = 0.042). Discussion/Conclusion Fontan patients had a lower-than-expected time-to-exhausiton, in part due to their abnormal ventilatory response. First, the increased pulmonary restriction in the Fontan patients likely led to increased V̇E driven by a high fR during exercise. Second, Fontan patients showed decreased ventilatory reserve - which was significantly associated with respiratory muscle weakness. Third, patients showed significantly increased respiratory muscle fatigue following exercise. Collectively, these factors likely contributed to the increased breathlessness and respiratory exertion in patients, leading to increased exercise limitation. Given this, and the fact that patients reached near maximal physiological responses during the CLCT, it’s possible that patients may benefit more from aerobic training at less than 70% of peak word rate, or from interval-training with significant recovery time.

Differences in the performance of bullfighters during a bullfight. Does bull behavior have direct influ-ence on the variables determining professional bullfighter’s performance?

The aim of the study was to analyze whether the physiological variables and movement time of bullfighters are different with each bull fought during a professional bullfight. For this purpose, heart rate monitors were used to record heart rate parameters and GPS to record the speed and distance traveled of three bullfighters during the fight with six bulls (n = 6). The results found show that performance variables such as maximum heart rate (P &lt;0.001; CV = 53.55%), TRIMPS (P = 0.006; CV = 53.55%), total distance traveled (P = 0.001; CV = 26.45), average speed (P = 0.001; CV = 26.45) different with each bull due to the variability in the behavior of the bull during the fight, which increases as the intensity increases. At the same time, the average heart rate achieved by the bullfighters during the fight, despite being different with each of the bulls (p &lt;0.001), presents a coefficient of variation of 4.24%, which means that the average heart rate parameters are homogeneous. It is possible to establish indications that the average heart rate of the bullfighters is within the confidence interval (143.61, 169.06). Our findings could help physical trainers and researchers better understand the context of bullfighting from the point of view of sports performance. Key words: Bull, performance, heart rate, variability, bullfighter.

Heart rate in newborns is associated with age, sex and maternal levothyroxine therapy.

To evaluate the definition and causes of neonatal bradycardias. This retrospective study included 135 term-born newborns referred for 24-hour Holter monitoring due to bradycardia. Bradycardia was defined as either a heart rate below 80 beats per minute (standard definition) or a heart rate below our recently published age-specific reference values for neonatal heart rate. The mean (SD) age was 6.1 (1.3) days. With standard definition, 107 newborns (79%) had bradycardia, whereas only 20 (15%) had a minimum heart rate lower than the age-specific reference. Younger newborns had lower heart rates. Each day increased the minimum, mean and maximum heart rate by 1.8 (95% CI: 1.0, 2.6), 4.2 (95% CI: 3.0, 5.3) and 2.1 beats per minute (95% CI: 0.3, 3.8), respectively. Male sex and maternal levothyroxine medication were negatively associated with the mean and maximum heart rate. None of the newborns had a cardiac cause for low heart rate. Among term newborns with bradycardias, younger age, male sex and maternal levothyroxine medication were associated with a lower heart rate on Holter monitoring. Given the age-related increase in heart rate, the 80 beats per minute limit as a universal threshold for abnormal heart rate in newborns appears inappropriate.

Shifting the Energy Toward Los Angeles: Comparing the Energetic Contribution and Pacing Approach Between 2000- and 1500-m Maximal Ergometer Rowing.

To compare the energetic contribution and pacing in 2000- and 1500-m maximal rowing-ergometer performances. On separate visits (>48 h apart, random order), 18 trained junior (16.7 [0.4]y) male rowers completed 3 trials: a7 × 4-minute graded exercise test, a2000-m time trial (TT2000), and a1500-m TT (TT1500). Respiratory gases were continuously measured throughout each trial. The submaximal power-to-oxygen-consumption relationship from the graded exercise test was used to determine the accumulated oxygen deficit for each TT. Differences in mean power output (MPO), relative anaerobic contribution, percentage of peak oxygen uptake, pacing index, maximum heart rate, rating of perceived exertion, and blood lactate concentration were assessed using linear mixed modeling. Compared to TT2000 (324 [24]W), MPO was 5.2% (3.3%) higher in TT1500 (341 [29W]; P < .001, ηp2=.70). There was a 4.9% (3.3%) increase (P < .001, ηp2=.71) in anaerobic contribution from 17.3% (3.3%) (TT2000) to 22.2% (4.3%) (TT1500). Compared to TT1500, maximum heart rate, rating of perceived exertion, and blood lactate concentration were all greater (P < .05) in TT2000. The pacing index was not different between trials. Percentage increase in MPO from TT2000 to TT1500 was negatively associated with pacing variance in TT1500 (R2 = .269, P = .027). Maximal ergometer performance over 1500m requires a significantly greater anaerobic contribution compared with 2000m. Junior male athletes adopt a consistent pacing strategy across both distances. However, those who experienced greater percentage increases in MPO over the shorter test adopted a more even pacing strategy. To prepare for 1500-m performance, greater emphasis should be placed on developing capacity for work in thesevere domain and completing race simulations with a more even pacing strategy.

Local environments, not invasive hybridization, influence cardiac performance of native trout under acute thermal stress.

Climate-induced expansion of invasive hybridization (breeding between invasive and native species) poses a significant threat to the persistence of many native species worldwide. In the northern U.S. Rocky Mountains, hybridization between native cutthroat trout and non-native rainbow trout has increased in recent decades due, in part, to climate-driven increases in water temperature. It has been postulated that invasive hybridization may enhance physiological tolerance to climate-induced thermal stress because laboratory studies indicate that rainbow trout have a higher thermal tolerance than cutthroat trout. Here, we assessed whether invasive hybridization improves cardiac performance response to acute water temperature stress of native wild trout populations. We collected trout from four streams with a wide range of non-native admixture among individuals and with different temperature and streamflow regimes in the upper Flathead River drainage, USA. We measured individual cardiac performance (maximum heart rate, "MaxHR", and temperature at arrhythmia, "ArrTemp") during laboratory trials with increasing water temperatures (10-28°C). Across the study populations, we observed substantial variation in cardiac performance of individual trout when exposed to thermal stress. Notably, we found significant differences in the cardiac response to thermal regimes among native cutthroat trout populations, suggesting the importance of genotype-by-environment interactions in shaping the physiological performance of native cutthroat trout. However, rainbow trout admixture had no significant effect on cardiac performance (MaxHR and ArrTemp) within any of the three populations. Our results indicate that invasive hybridization with a warmer-adapted species does not enhance the cardiac performance of native trout under warming conditions. Maintaining numerous populations across thermally and hydrologically diverse stream environments will be crucial for native trout to adapt and persist in a warming climate.

Energy Consumption and Substrate Utilization During Spinal Surgery.

This study aims to measure surgeon physiologic stress and energy expenditure during adult spine surgery. Energy expenditures were assessed based on patient BMI, lead use, instrumentation/intraoperative navigation, primary/revision surgeries, tranexamic acid (TXA) use, and anatomic region involved. The senior author wore a heart rate (HR) monitor and triaxial accelerometer during spinal surgeries, providing assessments of mean HR, maximum HR, calories consumed/minute, and calories as measured by a Polar device (P calories) and Fitbit device (F calories). One hundred sixty-two surgeries were included. Median patient age was 62 years. Median BMI was 29.02. Significant differences existed for BMI and estimated blood loss (P < 0.05). TXA use had a significant effect on case time, estimated blood loss, P calories, F calories, and Kcal/min (P < 0.05). Instrumentation use was significant for all variables (P < 0.05), except for mean HR and Kcal/min (P > 0.05). Lead use did not have a significant effect on max HR, P calories, F calories, and Kcal/min (P > 0.05). Navigation use was associated with significant differences for every variable tested (P ≤ 0.05). Differences were observed between primary and revision surgeries for case time, estimated blood loss, and F calories (P < 0.05). In spinal surgery, the use of navigation, instrumentation use, TXA use, and performing revision surgeries were associated with increased energy expenditure and can potentially increase surgeon fatigue.

The First Season After the COVID-19 Pandemic Cardiorespiratory and Statistics’ Performance in Czech Ice Hockey Players

The study describes the cardiorespiratory and statistics performance of ice hockey players during the season of 2020 after the COVID-19 lockdown’. Eight elite Czech male players (4 non-COVID-19 and 4 COVID-19 groups) were evaluated before and after the competition season. Players performed a cardiorespiratory exercise test and the maximal oxygen consumption, ventilatory threshold, respiratory compensation point, maximal heart rate and test time were measured. The number of matches, goals and plus/minus statistics were retained. No significant differences between groups before and after the season for all cardiorespiratory responses were found, and the no-COVID-19 group played more games. The conclusion highlights that the cardiorespiratory performance place all players (with and without COVID-19 history) in similar conditions to be prepared for the next season. Due to a wide variation among players’ statistics, based on plus/minus parameters, cannot be established that the 2020 season impaired the players’ statistics.