Anaerobic Threshold Research Articles

Effects of sacubitril/valsartan on the functional capacity of real-world patients in Italy: the REAL.IT study on heart failure with reduced ejection fraction.

Heart failure (HF) significantly affects the morbidity, mortality, and quality of life of patients. New therapeutic strategies aim to improve the functional capacity and quality of life of patients while controlling HF-related risks. Real-world data on both the functional and cardiopulmonary exercise capacities of patients with HF with reduced ejection fraction upon sacubitril/valsartan use are lacking. A multicenter, retrospective, cohort study, called REAL.IT, was performed based on the data collected from the electronic medical records of nine specialized HF centers in Italy. Cardiopulmonary exercise testing was performed at baseline and after 12 months of sacubitril/valsartan therapy, monitoring carbon dioxide production (VCO2) and oxygen consumption (VO2). The functional capacities of 170 patients were evaluated. The most common comorbidities were hypertension and diabetes (i.e., 53.5 and 32.4%, respectively). At follow-up, both the VO2 peak (from 15.1 ± 3.7 ml/kg/min at baseline to 17.6 ± 4.7 ml/kg/min at follow-up, p < 0.0001) and the predicted % VO2 peak (from 55.5 ± 14.1 to 65.5 ± 16.9, p < 0.0001) significantly increased from baseline. The VO2 at the anaerobic threshold (AT-VO2) increased from 11.5 ± 2.6 to 12.5 ± 3.3 ml/kg/min (p = 0.021), and the rate ratio between the oxygen uptake and the change in work (ΔVO2/Δwork slope) improved from 9.1 ± 1.5 to 9.9 ± 1.6 ml/min/W (p < 0.0001). Sacubitril/valsartan improves the cardiopulmonary capacity of patients with HFrEF in daily clinical practice in Italy.

Adverse Effect of Bundle Branch Block on Exercise Performance in Patients with Fontan Physiology: From the Pediatric Heart Network Fontan Public Data Set.

Patients with Fontan physiology have reduced exercise performance compared to their peers as well as a higher incidence of bundle branch block (BBB). This study aims to investigate the association between BBB and exercise performance in the Fontan population through a retrospective review of the Pediatric Heart Network Fontan study public use dataset. "Low Performers" were defined as ≤ 25th percentile (for Fontan patients) for each exercise parameter at anaerobic threshold (AT) for gender and age and "Normal Performers" were all other patients. A total of 303 patients with Fontan physiology who underwent exercise testing reached AT and had complete data for BBB. BBB occurred more frequently in Low Performers for VO2 [OR (95% CI): 2.6 (1.4, 4.8)] and Work [OR (95% CI): 2.7 (1.4, 5.1)], suggesting that BBB in the Fontan population is associated with reduced exercise performance. This data adds to the existing clinical evidence of the adverse effects of conduction abnormalities on single ventricle cardiac output and adds support for consideration of cardiac resynchronization and multi-site ventricular pacing in this patient population.

Progressive overload in cardiorespiratory exercise training for young and old: Is increasing duration or intensity of exercise more important?

People undertake endurance training to improve their health and cardio-respiratory fitness. Subsequent cardio-respiratory and skeletal muscle aerobic metabolic adaptations are gauged by improvements in maximum or peak oxygen uptake (V̇O2peak) and the blood lactate inflection point or threshold during incremental exercise – (LIP). To further improve physiological capability, subsequent homoeostatic disturbances from exercise should be progressively greater in succeeding exercise sessions. Therefore, exercise duration, frequency or intensity should be progressively increased during a training regimen to ensure adaptation potential is realized. A progressive increase in training workload is termed “progressive overload”. Despite the universal acknowledgment of the importance of progressive overload, it is unclear if systematically progressing altering either exercise intensity or duration (or distance covered) affect cardio-respiratory gains differently in young and older populations. As running faster results in higher heart rates and greater skeletal muscle metabolic stress than running the same distance at a lower speed, in this hypothesis we postulate that progressively increasing exercise run intensity will result in greater mean and higher incidence of V̇O2peak and LIP gains in young adults (<50 years). However, the mechanisms that initiate improvements in cardio-respiratory fitness and skeletal muscle aerobic function may be different in older adults due to the inevitable aging decline in cardio-vascular function and mechanical and morphological properties of muscle–tendon units. In older adults (>60 years) we hypothesize progressively increasing run distance while maintaining the same speed will just be as effective as to progressively increasing speed to improve V̇O2peak and LIP. To test these hypotheses, we propose a study that compares progressively increasing run intensity to a treatment of progressive matched run distance where speed remains constant in young and old adults.

Correlation between preoperative cardiopulmonary exercise testing and six-minute walk test, five-times sit to stand test and Short Form-36 physical component score in patients undergoing cytoreductive surgery

IntroductionAssessment of preoperative function is important for determining fitness for surgery, preoperative optimisation and predicting postoperative morbidity in patients undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). This study explored correlations between preoperative cardiopulmonary exercise testing (CPET) variables, and six-minute walk test (6MWT), five-times sit to stand test (5STS) and Short Form-36 (SF-36) physical component score in patients scheduled for elective CRS-HIPEC. MethodsThis study included patients who underwent preoperative CPET, 6MWT, 5STS and responded to the SF-36 survey prior to elective CRS-HIPEC at Royal Prince Alfred Hospital in Sydney. CPET was performed using a cycle ergometer and measured peak oxygen uptake (VO2 peak) and anaerobic threshold (AT). The associations between preoperative CPET variables and preoperative 6MWT, 5STS and SF-36 were assessed using correlation test. ResultsA total of 133 patients scheduled for elective CRS-HIPEC were included in this study. The median VO2, AT and VE/VCO2 were 20.3 [6.5] ml/kg/min, 13.1 [4.9] ml/kg/min and 29 [4.5], respectively. The median 6MWT, 5STS and SF-36 physical component score were 525 m, 9.2 s and 50.2, respectively. CPET variables were significantly correlated with 6MWT (VO2 r = 0.51; AT r = 0.35; VE/VCO2 r = −0.25; p < 0.01), 5STS (VO2 r = −0.32; AT r = −0.27; VE/VCO2 r = 0.24; p < 0.01) and SF-36 (VO2 r = 0.42; AT r = 0.38; VE/VCO2 r = −0.23; p < 0.01). Conclusions6MWT, 5STS and SF-36 are at best moderately correlated with CPET variables, which suggests that these tests may serve as adjuncts rather than a replacement to CPET in the clinical setting.

Effects of high-intensity interval training and resistance training on physiological parameters and performance of well-trained runners: A randomized controlled trial

ABSTRACT This study aimed to verify the effects of 4 weeks of high-intensity interval training (HIIT), heavy (HRT) and explosive (ERT) resistance training on aerobic, anaerobic and neuromuscular parameters and performance of well-trained runners. Twenty-six male athletes were divided into HIIT (n = 10), HRT (n = 7) and ERT (n = 9) groups. Maximal oxygen uptake ( V O 2 max ) and the corresponding velocity ( vV O 2 max ), anaerobic threshold (AT), running economy (RE), oxygen uptake kinetics, lower-body strength (1RM) and power (CMJ), and the 1500m and 5000m time-trial (TT) were determined. Improvements were observed in vV O 2 max (mean difference (Δ): 2.6%; effect size (ES): 0.63) with HIIT, while AT was incresead in ERT (Δ: 4.3%; ES: 0.73) and HRT (Δ: 6.9%; ES: 0.72) groups. The CMJ performance was increased in ERT (Δ: 13.8%; ES: 1.03), HRT (Δ: 6.9%; ES: 0.55) and HIIT (Δ: 5.4%; ES: 0.34), whereas 1RM increase in HRT (Δ: 38.1%; ES: 1.21) and ERT (Δ: 49.2%; ES: 0.96) groups. HIIT improved the 1500m (Δ: −2.3%; ES: −0.62) and both HRT (Δ: −1.6%; ES: −0.32) and ERT (Δ: −1.7%; ES: −0.31) the 5000m TT. Despite performance adaptations were dependent on the training characteristics, both RT and HIIT model constitute an alternative for training periodization.

Garmin Fénix 7® Underestimates Performance at the Lactate Threshold in Comparison to Standardized Blood Lactate Field Test.

Lactate threshold (LT) is a critical performance measure traditionally obtained using costly laboratory-based tests. Wearables offer a practical and noninvasive alternative for LT assessment in recreational and professional athletes. However, the comparability of these estimates with the regular field tests requires further evaluation. In our sample of 26 participants (nf=7 and nm=19), we compared the estimated running pace and heart rate (HR) at LT with two subsequent tests. First, participants performed the Fenix 7® threshold running test after a calibration phase. Subsequently, they were tested in a standardized, graded blood lactate field test. Age was 25.97 (± 6.26) years, and body mass index (BMI) was 24.58 (± 2.8) kg/m2. Pace at LT calculated by Fenix 7® (M=11.87 km/h±1.26 km/h) was 11.96% lower compared to the field test (M=13.28 km/h±1.72 km/h), which was significant (p <0.001, d=-1.19). HR estimated by the Fenix 7® at LT was 1.71% lower (p>0.05). LT data obtained in the field test showed greater overall variance. Our results suggest sufficient accuracy of Fenix 7® LT estimates for recreational athletes. It can be assumed that for professional athletes, it would fail to provide the nuanced data needed for high-quality training management.

Cardiopulmonary Exercise Testing Predicts Postoperative Morbidity after Major Abdominal Cancer Surgeries: A Prospective Observational Study

Background and Aim: Cardiopulmonary exercise testing (CPET) has been shown to predict outcomes after major surgery. However, CPET performance and risk thresholds may vary geographically due to different body composition, nutritional status, anaemia, etc. This study aimed to investigate the relationship between preoperative CPET variables and in-hospital morbidity after abdominal cancer surgeries. Methods: In this prospective observational study, 142 patients aged 18–70 years, American Society of Anesthesiologists Physical Status II–III, underwent CPET preoperatively within 7 days of planned surgery. Oxygen uptake (VO2), ventilatory equivalents for carbon dioxide, heart rate (HR) and oxygen pulse (VO2/HR) were measured at anaerobic threshold (AT) and peak exercise (PE). Morbidity was assessed using the postoperative morbidity survey (POMS) postoperatively on days 3, 5 and 7. Receiver operating characteristic (ROC) curves were constructed to assess the optimal cut-offs for various CPET parameters. A multivariate logistic regression model was applied to test the relationship between CPET and postoperative morbidity. Results: After excluding patients who met the exclusion criteria, data from 109 participants were available for analysis. Forty-two patients (39%) suffered some morbidity postoperatively. VO2@AT (univariate odds ratio (OR) 1.36 [1.11–1.67] P = 0.002), sex (0.40 [0.17–0.99] P = 0.04), HR@AT (0.91 [0.94–0.99] P = 0.01), VO2/HR@AT (2.00 [1.42–2.80] P &lt; 0.001) and VO2/HR@PE (2.04 [1.45–2.87] P &lt; 0.001] were associated with postoperative morbidity. The final multivariate regression model contained VO2@AT (multivariate OR 1.25 [1.00–1.56] P = 0.04) and VO2/HR@PE (1.89 [1.34–11.09] P = 0.001). ROC curves revealed the optimal cut-off for VO2@AT as 11.9 ml/kg/min and VO2/HR@PE at 6.1 ml/beat. Conclusion: CPET parameters of oxygen uptake at AT and oxygen pulse at PE can predict morbidity in patients undergoing major abdominal onco-surgeries.

Age Comparisons of Cardiac Work During Exercise in Women: Insight from Acute β1 Adrenergic Blockade

Postmenopausal women exhibit exaggerated increases in blood pressure during activities of daily living and exercise. The decreased size and increased stiffening of postmenopausal women's hearts elevate myocardial oxygen demand when compared to age-matched men and younger cohorts. Together, this poses a risk to the safety of, and capacity for, exercise in postmenopausal women. We recently studied the effects of esmolol, a fast-acting, cardio-selective β1 antagonist, on oxygen transport variables during dynamic exercise in healthy young (Y) and older (O) women to better understand differences in cardiovascular responses to exercise. Objective: Determine the effects of acute cardiac specific blockade on myocardial oxygen demand (rate pressure product, RPP) and cardiac work (CW) in healthy young premenopausal and older postmenopausal women. Methods: Thirteen healthy young (20-32 yr) and older postmenopausal (58-70 yr) women performed moderate (85% of lactate threshold) and heavy (50% between lactate threshold and the respiratory compensation point) recumbent leg cycling exercise during IV infusion of saline or esmolol in randomized order. Whole body oxygen consumption (VO2, indirect calorimetry), brachial systolic blood pressure (SBP, automated cuff), heart rate (HR, ECG), and cardiac output (CO, bioimpedance) were measured continuously. RPP (HR×SBP), CW (CO×SBP), and cardiac effciency (CE, CW/VO2) were calculated. Mixed model repeated measures ANOVAs were used to determine the effect of treatment and age group. Results: Power outputs were lower in O vs. Y at both moderate (45±9W and 72±15W, p&lt;0.001) and heavy (81±21W vs. 117±32W, p&lt;0.001) intensities. During the saline trial CO was lower (p&lt;0.001), and RPP was higher (p&lt;0.001) in the O vs. Y group during both intensities. There was a main effect of treatment on RPP, CW, and CE. Esmolol reduced RPP (4638±775 SD, p&lt;0.001), CW (547±89, p&lt;0.001) and CE (1682±62, p&lt;0.001) in both O and Y. There was a main effect of age group on CE, pairwise comparisons showed CE was lower in O than Y (441±112, p&lt;0.001). Conclusions: Older postmenopausal women experience higher myocardial oxygen demand and perform more cardiac work for a given whole body liter oxygen consumed during dynamic leg exercise compared to younger premenopausal women. Acute β1 adrenergic blockade narrows the gap between central cardiovascular function in young and old women and provides a powerful tool to investigate age-related cardiovascular differences. NIH R21 AG054940. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A VALIDATION OF A NOVEL RUNNING ECONOMY PROTOCOL AND COMPARISON OF TWO CARBON-PLATED RUNNING SHOES IN FEMALE LONG-DISTANCE RUNNERS

INTRODUCTION Running economy (RE) is the strongest predictor of long-distance running performance in well-trained athletes (1). Carbon-plated running shoes have indicated improvements of 4% in RE when compared to previous generation non-carbon-plated running shoes (2). However, these studies have key methodological limitations; the prescribed intensities didn’t replicate race demands, the influence of fatigue was not considered, and testing was only completed on males. AIM: The primary aim of this study was to develop an appropriate protocol to measure RE in female long-distance runners. The secondary aim was to compare performance and RE of two carbon-plated performance shoes in female long-distance runners. METHODS Seven female endurance athletes (age: 30.7 ± 6.6 y, mass: 59.1 ± 5 kg, VO2max: 55.3 ± 4.1 ml/kg/min) completed a graded exercise test to establish a relative race intensity (90% of lactate threshold). Participants completed two testing sessions during the follicular phase of the menstrual cycle in alternating footwear, which consisted of four 7-minute trials, a 25-minute continuous run, four 7-minute trials, and a 13-minute distance trial. RE was recorded as the oxygen consumption and energetic cost of running from minutes 5-7 of each trial. Shoe preference was recorded midway through the first session and the end of the second session. A linear mixed model was used to compare economy and performance metrics. RESULTS There was no significant difference in RE because of fatigue and no significant difference between shoes. However, large individual variations were evident. Participants reported disagreement between preferred shoe and the shoe that demonstrated greatest RE. CONCLUSION A longer protocol that controlled for the menstrual cycle did not induce fatigue related changes in female participants, supporting a higher resistance to fatigue in females (3). The individual variation between shoes suggests that further analyses should be conducted to inform shoe selection for female long-distance runners.

The effects of partial sleep deprivation on blood pressure responses during cycling are intensity dependent

Introduction: Exaggerated blood pressure (BP) responses during exercise are associated with increased risk of clinical cardiovascular outcomes. Partial sleep deprivation (PSD), defined as ≤6 hours of sleep, can increase 24-hour ambulatory BP but the effects on exercise BP have not been studied. We hypothesized that acute PSD would augment the exercise BP response to constant load exercise (below and above estimated lactate threshold) and during a 20-min time trial. Methods: Fourteen, healthy adults (22 ± 3 years; 9 males; VO2peak: 43.2 ± 9.5 ml/kg/min [25.3-60.9]) completed a randomized crossover trial where they slept normally (normal sleep-wake schedule for each participant), or sleep was partially deprived (early awakening, 40% of normal sleep duration). Prior to the testing visits, participants completed two familiarization visits under normal sleep conditions. Each participant completed a 12-minute warm (6-minutes below estimated lactate threshold [moderate intensity; 65 ± 24 W] and 6-minutes above estimated lactate threshold but below respiratory compensation point [heavy intensity; 147 ± 60 W]) followed by a time-trial where they were asked to cycle as far as possible in 20 minutes. BP was assessed at rest (BpTRU, Medical Devices) and on the cycle ergometer every 2 minutes during the warmup and 20-minute time-trial (Tango M2, SunTech Medical). Sleep timing and duration was assessed daily for 1-week prior to each testing visit using self-report and an accelerometer worn on the non-dominate wrist (wGT3X-BT, ActiGraph). Results: Resting systolic ( P=0.08) and diastolic BP ( P=0.06) tended to be higher following PSD (normal sleep: 105 ± 8/62 ± 8 mmHg vs. PSD: 107 ± 6/64 ± 7 mmHg). PSD did not alter VO2 during the moderate- (normal sleep: 1291 ± 394 ml/min vs. PSD: 1258 ± 364 ml/min) and heavy-intensity (normal sleep: 1903 ± 758 ml/min vs. PSD: 1893 ± 724 ml/min) warmup or 20-minute time-trial (normal sleep: 2713 ± 1120 ml/min vs. PSD: 2669 ± 1134 ml/min) or distance covered (normal sleep: 10.16 ± 2.024 km vs. PSD: 10.08 ± 2.145 km) and power output (normal sleep: 175 ± 79 W vs. PSD: 173 ± 79 W) during the 20-min time-trial (all P&gt;0.27). Systolic (normal sleep: 140 ± 17 mmHg vs. PSD: 136 ± 11 mmHg, P=0.14) and diastolic (normal sleep: 67 ± 11 mmHg vs. PSD: 69 ± 8 mmHg, P=0.44) BP did not differ during the moderate-intensity warmup following PSD. However, systolic BP was lower during the heavy-intensity warmup (normal sleep: 165 ± 25 mmHg vs. PSD: 155 ± 22 mmHg, P=0.008) and 20-minute time-trial (normal sleep: 174 ± 20 mmHg vs. PSD: 165 ± 25 mmHg, P=0.05) following PSD. No differences were observed in diastolic BP (all P&gt;0.57). Heart rate during the moderate-intensity warmup (normal sleep: 110 ± 11 bpm vs. PSD: 110 ± 10 bpm), heavy-intensity warmup (normal sleep: 137 ± 14 bpm vs. PSD: 136 ± 14 bpm), and time-trial (normal sleep: 171 ± 16 bpm vs. PSD: 169 ± 19 bpm) did not differ between conditions (all P&gt;0.39). Conclusion: In contrast to our hypothesis, these preliminary findings suggest that a single night of PSD results in lower systolic BP responses during heavy-intensity, but not moderate-intensity, cycling exercise. This research was supported by a Natural Science and Engineering Research Council (NSERC) of Canada Discovery Grant (P.J.M). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Applying ICF Framework to Explore the Factors That Influence Quality of Life in Patients After Lung Surgery.

To explore the relationship between pulmonary function, physical activity, and health-related quality of life (QoL) in resected lung cancer patients based on the International Classification of Functioning, Disability, and Health (ICF) framework developed by the World Health Organization to describe health and health-related states. A quantitative study was designed with postoperative lung cancer survivors to assess personal characteristics. We also assessed functional impairment related to the lung using forced vital capacity (FVC) and forced expiratory volume at 1 second (FEV1), activity limitations using maximal oxygen consumption (VO2max), anaerobic threshold (AT) and 6-minute walking distance (6MWD), and participation restriction using the 36-item Short Form Health Survey V1 (SF-36). Data analyses were conducted using the multivariate method and Smart- PLS to examine path coefficient among the measures. Forty-one patients were enrolled in this study. FVC and FEV1 were poorly correlated with QoL, and 6MWD, AT, or VO2max were positively associated with QoL. AT or VO2max showed a significant (p<0.01) direct path with SF-36 in the ICF model. Although age and body mass index were not strongly correlated with QoL, these personal factors had a medium to large effect on perceived QoL. Disability is a complex in patients with lung resection, and physical activity plays an important role in enabling participation. Improving VO2max and AT is needed to improve the QoL of resected lung cancer patients. We should also pay more attention to contextual factors that have a significant impact on social participation.

Health-related quality of life in children and adolescents with Marfan syndrome or related disorders: a controlled cross-sectional study

BackgroundThis cross-sectional controlled study aims to assess health-related quality of life (HRQoL) of children and adolescents with a molecular diagnosis of Marfan syndrome (MFS) or related disorders and to evaluate the factors associated with HRQoL in this population. Sixty-three children with MFS and 124 age- and sex-matched healthy children were recruited. HRQoL was assessed using the Pediatric Quality of Life Inventory (PedsQL™) generic questionnaire. The correlation between HRQoL scores and the different continuous parameters (age, body mass index, disease severity, systemic score, aortic sinus diameter, and aerobic physical capacity) was evaluated using Pearson’s or Spearman’s coefficient. A multiple linear regression analysis was performed on the two health summary self-reported PedsQL™ scores (physical and psychosocial) to identify the factors associated with HRQoL in the MFS group.ResultsExcept for emotional functioning, all other domains of HRQoL (psychosocial and physical health, social and school functions) were significantly lower in children with MFS compared to matched healthy children. In the MFS group, the physical health summary score was significantly lower in female than in male patients (self-report: absolute difference [95%CI] = -8.7 [-17.0; -0.47], P = 0.04; proxy-report: absolute difference [95%CI] = -8.6 [-17.3; 0.02], P = 0.05) and also negatively correlated with the systemic score (self-report: R = -0.24, P = 0.06; proxy-report: R = -0.29, P = 0.03) and with the height Z-score (proxy-report: R = -0.29, P = 0.03). There was no significant difference in the physical health summary scores between the different genetic subgroups. In the subgroup of 27 patients who performed a cardiopulmonary exercise test, self- and proxy-reported physical health summary scores were highly correlated with their aerobic physical capacity assessed by peak oxygen consumption (VO2max) and ventilatory anaerobic threshold (VAT). In the multivariate analysis, the most important independent predictors of decreased physical health were increased height, decreased body mass index, decreased VAT and use of prophylactic therapy.ConclusionsThis study reports an impaired HRQoL in children and adolescents with MFS or related conditions, in comparison with matched healthy children. Educational and rehabilitation programs must be developed and evaluated to improve exercise capacity and HRQoL in these patients.Trial registrationClinicalTrials.gov, NCT03236571. Registered 28 July 2017.

Effect of Sugar- and Polyphenol-Rich, Diluted Cloudy Apple Juice on the Intestinal Barrier after Moderate Endurance Exercise and in Ultra-Marathon Runners.

Exercise and the consumption of sugars result in a dysfunction of the intestinal barrier (IB). Here, we determined the effect of sugar in a natural matrix on the intestinal barrier after moderate (A) and intensive endurance exercise (B). The IB function was determined before (pre) and after running (post), and 120 and 180 min after consuming the drink by measuring serum endotoxin concentrations (lipopolysaccharides-LPS), IL-6, CD14, and i-FABP. In study A, nonspecifically trained participants (n = 24, males and females, age 26 ± 4) ran for one hour at 80% of their individual anaerobic threshold (IAT). After finishing, the runners consumed, in a crossover setup, either 500 mL of water, diluted cloudy apple juice (test drink), or an identical drink (placebo) without the fruit juice matrix (FJM). In study B, the participants (n = 30, males and females, age 50 ± 9) completed an ultra-marathon run, were divided into groups, and consumed one of the above-mentioned drinks. Study A: Exercise resulted in a significant increase in serum LPS, i-FABP, and IL-6, which decreased fast after finishing. No impact of the different drinks on LPS i-FABP, or IL-6 could be observed, but there was an impact on CD14. Study B: The ultra-marathon resulted in a strong increase in serum LPS, which decreased fast after finishing in the water and test drink groups, but not in the placebo group. The consumed drinks did not affect the kinetics of IB regeneration after moderate exercise, but impacted CD14 serum concentrations, indicating possible beneficial effects of the FJM on the immune system. After an ultra-marathon, IB function regenerates very fast. The intake of sugar (placebo) seems to have had a negative impact on IB regeneration, which was diminished by the presence of the FJM.

Exercise capacity prior to major cancer surgery: A cross-sectional observational study of the validity of the 6-minute walk and 30-second sit-to-stand tests.

Cardiopulmonary exercise testing (CPET) is the gold standard for measuring exercise capacity, however, it is resource intensive and has limited availability. This study aimed to determine: 1) the association between the 6-min walk test (6MWT) and the 30-s sit-to-stand test (30STS) with CPET peak oxygen uptake (VO2peak) and anaerobic threshold (AT) and 2) 6MWT and 30STS cut points associated with a higher risk of postoperative complications. A cross-sectional study, retrospectively analyzing data collected from a tertiary cancer center over a 23-month period. Measures included CPET VO2peak and AT, 6MWT and 30STS test. Correlations were used to characterize relationships between variables. Receiver operating characteristic curve analyses determined 6MWT and 30STS cut points that aligned with CPET variable cut points. Note that, 156 participants were included. The 6MWT and 30STS displayed moderate correlations with VO2peak, rho=0.65, p=0.01 and rho=0.52, p<0.005 respectively. Fair correlations were observed between AT and 6MWT (rho=0.36, p=0.01) and 30STS (rho=0.41, p<0.005). The optimal cut points to identify VO2peak<15mL/kg/min were 493.5m on the 6MWT and 12.5 stands on the 30STS test and for AT<11mL/kg/min were 506.5m on the 6MWT and 12.5 stands on the 30STS test. Both the 6MWT and 30STS test could be used as alternative tools for measuring exercise capacity preoperatively in the cancer setting where CPET is not available. A range of 6MWT and 30STS cut points, according to sensitivity and specificity levels, may be used to evaluate risk of postoperative outcomes.

Deriving fontan-specific normative exercise data from well-functioning adolescents

BackgroundExercise capacity is reduced in patients with a Fontan circulation compared to their healthy peers secondary to altered haemodynamics of the Fontan circulation. Cardiopulmonary exercise testing is routinely used in Fontan patients to assess their cardiopulmonary response to exercise and help guide management decisions, however their results are routinely compared to normative data derived from healthy individuals. MethodUsing data available from the Pediatric Heart Network, we performed a retrospective study to derive Fontan-specific normative values in a subgroup of well-functioning adolescent patients. We utilised results from the Congenital Heart Adolescent and Teenager (CHAT) Questionnaire to classify patients into well-functioning and lower-functioning groups. ResultsWe generated Fontan-specific regression equations in adolescent male and females for normative values of peak oxygen consumption (VO2), maximal workload and VO2 at anaerobic threshold. ConclusionWe propose that Fontan-specific normative values are a more useful comparison than healthy normative data due to the known circulatory limitations of the Fontan circulation and will assist in management decision and prognostication.

Higher Blood Lactate with Prolongation of Underwater Section in Submaximal Front-Crawl Swimming.

The underwater phase (UP) is highly important for overall swimming performance in most swimming events. However, the metabolic effects of the prolonged UP remain unclear. The purpose of this cross-sectional study was to compare the blood lactate response to submaximal front-crawl swimming with short and extended UP. Twelve (four females) junior competitive swimmers (aged 15.4 (1.4) years) undertook 200 m front-crawl swim trials in a 25 m pool at a pre-determined "anaerobic threshold" velocity on two occasions using short (<5 m) and extended (12.5 m) UP after each turn. Pacing and total time were ensured to be identical between the trials. Capillary blood lactate response was measured. Testing for 25 m swim time with <5 m and 12.5 m UP was conducted on a separate occasion. When athletes undertook and extended UP after each propulsion from the wall, their post-exercise blood lactate concentration reached 7.9 (2.1) mmol/L, more than two times higher than the response to trial with short UP (p < 0.001). All-out 25 m swimming with <5 m or 12.5 m UP disclosed no difference in locomotion velocity (p > 0.05). In conclusion, extending UP of submaximal front-crawl swimming close to maximally allowed during the races substantially increases blood lactate accumulation, i.e., increases the reliance on anaerobic metabolism. Therefore, extended UP is most likely counterproductive for the performance in long-distance swimming, at least for the athletes with a FINA score of <800. On the other hand, the extension of UP could be an effective strategy to train 'lactate tolerance', lactate shuttling, removal, and recycling.

A comparative analysis of the physical fitness profile of Korean women's national amateur boxers by weight category.

The purpose of this study was to examine the differences in specific physical fitness of the national amateur women's boxer. The Korean women's national amateur boxers were classified into the lightweight category (LWC, n=21) and middleweight category (MWC, n=13), and body composition (percentage body fat and body mass index) and specific physical fitness (maximal muscle strength, anaerobic power, isokinetic muscle strength, cardiopulmonary endurance) were measured. The Mann-Whitney U-test was conducted to determine the differences in the body composition and specific physical fitness in women's boxers. The percentage body fat (P=0.004) and body mass index (P<0.001) were significantly higher in the LWC compared to MWC. In addition, LWC showed significantly higher isokinetic muscle strength (P<0.001), upper anaerobic mean power (P=0.002), maximal muscle strength (P=0.003), and maximal heart rate at anaerobic threshold (P=0.029), maximal oxygen consumption (P<0.001) and the 20-m shuttle-run exercise (P=0.004) compared to MWC. In conclusion, the body fat percentage and body mass index levels among body composition were significantly higher in the MWC than in the LWC, and the constant muscle strength, maximum muscle strength, and cardiopulmonary endurance levels were significantly higher in the LWC than in the MWC. The results of this study are expected to provide useful data for planning future strategies for efficient and scientific training programs for each weight category.

Cardiopulmonary functional capacity in Taiwanese children with atrial septal defects.

Most existing studies measure atrial septal defect (ASD) outcomes based on morbidity rates such as atrial arrhythmias and heart failure rather than the functional assessment of physical capacity postprocedure. Few studies have evaluated cardiopulmonary function in ASD children. This study represents the largest sample population in the current research, encompassing a total of 122 Taiwanese children with ASD who had undergone treatment, to evaluate cardiopulmonary functional capacity through the implementation of cardiopulmonary exercise testing (CPET), and to investigate whether variations in treatment may impact their cardiopulmonary function. This is a retrospective cohort study with the data collected from January 2010 to December 2021. All patients and controls (age-, sex-, and body mass index-matched) underwent CPET and pulmonary function testing. In total, 122 ASD patients (surgically closed ASDs 27, transcatheter-closed ASDs 48, and follow-up unrepaired ASD 47) and 244 healthy controls were recruited. The ASD group exhibited lower peak metabolic equivalent (MET), peak oxygen consumption (VO 2 , p < 0.001), and peak minute ventilation ( p = 0.028) along with MET and VO 2 at the anaerobic threshold (AT) ( p = 0.012) compared to the control group. No statistically significant differences were observed in the pulmonary function test. Among surgically closed, transcatheter closed and unrepaired ASD subgroups, no significant variances were seen in CPET and pulmonary function tests. Taiwanese ASD children exhibited diminished exercise capacity and cardiopulmonary performance compared to their healthy counterparts. Differences among specific ASD treatments in cardiopulmonary tests were non-significant.

Borg's exertion scale did not coincide with ventilatory anaerobic threshold in atrial fibrillation patients with restored sinus rhythm after ablation.

The determination of precise exercise intensity is essential for effective exercise rehabilitation. The Borg rating of perceived exertion category ratio (CR) scale is utilized to prescribe an appropriate level of exertion intensity. A Borg CR of approximately 13 coincides with the ventilatory aerobic threshold (VAT). Patients with atrial fibrillation (AF) exhibit various symptoms. We hypothesized that the workload at Borg CR13 (Borg CR13-Watt) differs from the workload at the VAT level (VAT-Watt) in AF patients with restored sinus rhythm (SR) following ablation. Accordingly, the relationship between Borg CR13-Watt and VAT-Watt was studied in patients with restored SR. Cardiopulmonary exercise testing (CPET) was performed at 101±88 days after ablation in 150 patients using a bicycle ergometer. No adverse events were observed during CPET. Borg CR13-Watt was significantly higher than VAT-Watt (67.2±27.8 Watt vs. 54.7±17.6 Watt, P<0.0001). Borg CR13-Watt showed significant linear regression with VAT-Watt (regression coefficient, 0.49, P<0.01; correlation coefficient, 0.80, P<0.01). Higher Borg CR13-Watt was associated with greater differences between Borg CR13-Watt and VAT-Watt (ΔWatt). The Bland-Altman plot showed nonconcordance between the two. Male sex, use of antiarrhythmic drugs, and smoking had contributed to the increased ΔWatt. Duration from ablation to time of CPET did not correlate with ΔWatt. Therefore, Borg CR13-Watt did not coincide with VAT-Watt in patients with restored SR. Higher Borg CR13-Watt was associated with greater ΔWatt. Prescribing exertion intensity as determined solely by perceived exertion is inadequate. CPET is required to determine the precise exercise intensity in AF patients with restored SR after ablation.

The Effect of Acute Ketone Supplementation on Time to Fatigue in NCAA Division I Cross-Country Athletes

This study investigated the effect of a commercially available ketone supplement on heart rate (HR), perceived exertion (RPE), blood lactate, glucose, and ketone concentrations, along with time to fatigue (TTF) during a running task to voluntary fatigue. Twelve NCAA Division I cross-country athletes took part in this randomized, double-blind, placebo-controlled cross-over study. Bayesian methodologies were employed for all statistical analyses, and point estimates were determined to be statistically significant if the 95% highest-density intervals (HDI) excluded zero. TTF was not significantly different between conditions with a Meandiff = 48.7 ± 6.3 s (95% HDI: −335, 424) and a 0.39 probability derived from the posterior distribution, indicating the likelihood that the supplement would increase TTF compared to the placebo control. Lactate concentrations immediately post-exercise were significantly lower in the supplement trial relative to placebo with an estimated Meandiff = −4.6 ± 1.9 mmol; 95% HDI: −8.3, −0.9. There were no significant interaction effects observed for either blood glucose or ketone concentrations nor HR or RPE. These findings imply that the acute ingestion of ketones before running at lactate threshold pace has a low probability of increasing TTF in highly trained Division I runners.