Cardiorespiratory Fitness Parameters Research Articles

Assessing the Accuracy of Smartwatch-Based Estimation of Maximum Oxygen Uptake Using the Apple Watch Series 7: Validation Study.

Determining maximum oxygen uptake (VO2max) is essential for evaluating cardiorespiratory fitness. While laboratory-based testing is considered the gold standard, sports watches or fitness trackers offer a convenient alternative. However, despite the high number of wrist-worn devices, there is a lack of scientific validation for VO2max estimation outside the laboratory setting. This study aims to compare the Apple Watch Series 7's performance against the gold standard in VO2max estimation and Apple's validation findings. A total of 19 participants (7 female and 12 male), aged 18 to 63 (mean 28.42, SD 11.43) years were included in the validation study. VO2max for all participants was determined in a controlled laboratory environment using a metabolic gas analyzer. Thereby, they completed a graded exercise test on a cycle ergometer until reaching subjective exhaustion. This value was then compared with the estimated VO2max value from the Apple Watch, which was calculated after wearing the watch for at least 2 consecutive days and measured directly after an outdoor running test. The measured VO2max (mean 45.88, SD 9.42 mL/kg/minute) in the laboratory setting was significantly higher than the predicted VO2max (mean 41.37, SD 6.5 mL/kg/minute) from the Apple Watch (t18=2.51; P=.01) with a medium effect size (Hedges g=0.53). The Bland-Altman analysis revealed a good overall agreement between both measurements. However, the intraclass correlation coefficient ICC(2,1)=0.47 (95% CI 0.06-0.75) indicated poor reliability. The mean absolute percentage error between the predicted and the actual VO2max was 15.79%, while the root mean square error was 8.85 mL/kg/minute. The analysis further revealed higher accuracy when focusing on participants with good fitness levels (mean absolute percentage error=14.59%; root-mean-square error=7.22 ml/kg/minute; ICC(2,1)=0.60 95% CI 0.09-0.87). Similar to other smartwatches, the Apple Watch also overestimates or underestimates the VO2max in individuals with poor or excellent fitness levels, respectively. Assessing the accuracy and reliability of the Apple Watch's VO2max estimation is crucial for determining its suitability as an alternative to laboratory testing. The findings of this study will apprise researchers, physical training professionals, and end users of wearable technology, thereby enhancing the knowledge base and practical application of such devices in assessing cardiorespiratory fitness parameters.

Effects of HIIT Interventions on Cardiorespiratory Fitness and Glycemic Parameters in Adults with Type 1 Diabetes: A Systematic Review and Meta-Analysis.

Individuals with type 1 diabetes mellitus (T1DM) face impaired cardiorespiratory fitness and glycemic control, increasing the risk of cardiovascular complications. High-intensity interval training (HIIT) has emerged as a promising exercise modality with potential benefits for both aspects in this population. The primary aim was to investigate the effects of HIIT on cardiorespiratory fitness and glycemic parameters in patients with T1DM. The secondary aim was to examine the most effective HIIT protocol for cardiorespiratory fitness and glycemic parameters in patients with T1DM. Systematic review and meta-analysis. Two major electronic databases (Web of Science and PubMed) were searched up to February 2024. Randomized and non-randomized trials involving adult patients with T1DM, free of complications and other diseases examining the effects of HIIT (HIIT pre vs. post; HIIT vs. control group or HIIT vs. moderate-intensity continuous training (MICT)) on cardiorespiratory fitness and glycemic parameters were included. A total of ten studies met the inclusion criteria. The meta-analysis revealed a significant improvement in cardiorespiratory fitness following HIIT interventions (pre vs. post) in patients with T1DM (standardized mean difference (SMD) = 0.59, 95% confidence interval (CI) = 0.16 to 1, p = 0.01). Furthermore, HIIT (pre vs. post) was associated with significant improvements in 24-h mean glucose control (SMD = -0.44, 95% CI = -0.81 to -0.06, p = 0.02), but the results (pre vs. post) failed to identify significant improvements in fasting glucose (SMD = -0.26, 95% CI = -0.78 to 0.24, p = 0.3) and glycated hemoglobin (HbA1C) values (SMD = -0.28, 95% CI = -0.61 to 0.05, p = 0.1). However, in comparison with a control group, HIIT showed significantly favorable effects on HbA1C (SMD = -0.74, 95% CI = -1.35 to -0.14, p = 0.02). Finally, the meta-regression analysis did not find any moderating effect of any HIIT characteristics (i.e., intervention duration, session duration, work time, rest time, number of bouts, and intensity) on cardiorespiratory fitness and glycemic parameters. Our systematic review and meta-analysis show that T1DM patients who performed a HIIT intervention significantly improved cardiorespiratory fitness and reduced their 24-h mean glucose levels, but not their HbA1C and fasting glucose. These findings support the application of HIIT interventions in T1DM patients. However, the guidelines for the most effective protocol remain unclear; hence, future studies are needed.

Effectiveness of a 12-week telerehabilitation training in people with long COVID: A randomized controlled trial

BackgroundTelerehabilitation has been developed and applied for years for cardiac and pulmonary diseases with good clinical outcomes. However, its application to participants with long COVID remains limited. ObjectivesTo investigate the effectiveness of a 12-week telerehabilitation training program in participants with long COVID. The primary outcome was cardiorespiratory fitness (CRF), and secondary outcomes were physical activity (PA) amounts, exercise self-efficacy, sleep quality, and health-related quality of life (HRQOL). MethodsA parallel-group, randomized controlled trial was conducted. Eligible participants with long COVID (n = 182) were randomly assigned in a 1:1 ratio to either the experimental group (EG) or the control group (CG). The EG received 12 weeks of telerehabilitation training with weekly remote monitoring for exercise maintenance and support. The CG received PA counseling only. CRF, PA amounts, exercise self-efficacy, sleep quality, and HRQOL were assessed at baseline and 12 weeks. Generalized estimating equations were used to analyze the intervention effects by examining the interaction between time and group. ResultsOne hundred twenty-two participants (67 %) completed the study, and 182 were included in the intention-to-treat analysis. The EG had greater walking behavior (β = –763.3, p < 0.001), total amount of PA (β= –711, p = 0.003), exercise self-efficacy (β = –1.19, p < 0.001), and better sleep quality (β = 1.69, p = 0.012) after the 12-weeks of telerehabilitation training than the CG. However, there were no significant differences in any CRF parameters or HRQOL at 12 weeks between the EG and CG. ConclusionTelerehabilitation training offers a personalized and convenient approach that can increase exercise willingness and PA amounts and improve sleep quality. These findings underscore the potential benefits of telerehabilitation training for promoting healthier lifestyles and improving overall health outcomes. Clinical Trial RegistrationThe study was registered at ClinicalTrials.gov (NCT05205460) on January 25, 2022.

Echocardiographic Parameters Associated With Cardiorespiratory Fitness and Physical Activity in Childhood Acute Lymphoblastic Leukemia Survivors.

Children's exposure to chemotherapeutic agents causes several long-term adverse effects but physical activity has been evidenced to be an effective strategy to improve cardiac function. This cross-sectional study aimed to explore the association between physical activity levels, cardiorespiratory fitness, and cardiac parameters measured by echocardiography. Participants were 216n childhood acute lymphoblastic leukemia survivors who underwent a maximal cardiopulmonary exercise test and self-reported their daily minutes of moderate to vigorous physical activity. They underwent a complete transthoracic echocardiographic assessment. Systolic and diastolic function analysis and strain images analysis were performed. The associations were studied through the preventive fraction (examined with univariate crude and adjusted logistic regression models) of regular physical activity (≥150min·wk-1) and adequate cardiorespiratory fitness levels (above the median ≥ 32.0mL·kg-1·min-1) on cardiac parameters. Crude analysis shows that regular physical activity was associated with a significant preventive fraction in mitral E/A ratio (56%; P = .013), while adjusted analyses highlighted a nonsignificant reduction of 74% to 37% in the prevalence of cardiac parameters associated with physical activity. Similar associations of adequate cardiorespiratory fitness on cardiac parameters were observed. Adjusted analyses revealed a nonsignificant reduction of 7% to 86% in the prevalence of cardiac parameters associated with cardiorespiratory fitness. This study reports that regular physical activity and adequate cardiorespiratory fitness were associated with a higher preventive fraction. Thus, engaging in physical activity prevents childhood acute lymphoblastic leukemia survivors' cardiac dysfunctions. These findings are novel and clinically relevant in pediatric cardiooncology and provide additional evidence to strengthen the benefits of exercise as long-term care in childhood cancer survivors.

Comparative analysis of cardiorespiratory fitness, bio-motor abilities, and body composition indicators among sprint kayakers of different age groups and expertise levels.

This study compared cardiorespiratory fitness, bio-motor abilities, and body composition indexes of sprint kayakers categorized into three different age groups and two expertise levels of international- and club-level athletes. Seventy-three male juniors (n = 14, age = 16.2 ± 0.8), under 23 [U23 (n = 15, age = 20.2 ± 1.6)], professionals (n = 16, age = 27.1 ± 4.8), club-level (n = 15, age = 26.9 ± 6.6), and international-level (n = 13, age = 27.3 ± 3.2) sprint kayakers were studied. Cardiorespiratory fitness (assessed using incremental exercise test), 500 and 1,000-m paddling performance (assessed using kayak ergometer), upper-body power (assessed using 30s all-out Wingate test) and strength (assessed through one repetition tests for bench press, cable row, and prone bench pull exercises), as well as body composition indexes (measured using dual-energy X-ray absorptiometry) were evaluated on four occasions separated by 48h recovery. U23 and, especially, professionals indicated significantly (p < 0.05) greater outcomes for the majority of the cardiorespiratory fitness parameters [maximal oxygen uptake (VO2max), velocity corresponding to VO2max, Oxygen pulse, maximal ventilation, and second ventilatory threshold] and 500 and 1,000-m performance. U23 and professional sprint kayakers significantly (p < 0.05) differed in the first ventilatory threshold and 500, and 1,000-m performance but not in VO2max or the second ventilatory threshold. Professionals also showed a lower fat mass, higher muscle mass, and higher strength (bench press, prone bench pull, and seated cable row) and power than U23 and junior kayakers. Strength and power indicators had significantly greater values in U23 athletes compared to juniors. International-level athletes also showed superior VO2max, velocity corresponding to VO2max, middle (500-m), and long-distance (1,000-m) time trial performance, strength and power, lower fat, and higher muscle mass than club-level sprint kayakers. Cardiorespiratory fitness (particularly ventilatory threshold), body composition, and muscle strength/power are the best differentiating factors for sprint kayakers of different ages and expertise levels. These findings could aid coaches in prescribing training programs focusing on improving determining factors in paddling performance, as well as in predicting performance and identifying talent.

595-P: Exercise Training Improves Cardiorespiratory Parameters but Not VO2peak in People with Type 2 Diabetes

Maximal oxygen consumption (VO2peak), a measure of cardiorespiratory fitness (CRF), is a strong predictor of mortality. People with type 2 diabetes (T2D) have lower VO2peak compared to healthy controls, and unfortunately, studies suggest that training has limited effects to improve VO2peak in T2D. Although VO2peak is a key component, additional respiratory functions may also be important markers of cardio-metabolic fitness. Here, we determined the effects of a 10-week moderate-intensity exercise training program on VO2peak, power (indicator of muscle strength), VO2/work (index of the body’s efficiency at producing work), OUES (protective in heart failure), and ventilatory threshold (marker of aerobic endurance) in lean, obese, and T2D subjects. Training improved VO2peak in lean and obese, but not in T2D (Table 1). Likewise, training increased power, and tended to increase OUES in lean and obese, but not T2D. However, training was effective in increasing ventilatory threshold (VT) and VO2/Work in T2D, and also improved glycemic control (HbA1c). We hypothesize that the increased VT functions to improve training-induced muscular efficiency and capillary delivery, contributing to improved glycemic control. In conclusion, despite no change in VO2peak, exercise training increases multiple CRF and metabolic parameters in people with T2D, and should continue to be a mainstay in treatment of T2D. Disclosure R.Middelbeek: Research Support; Novo Nordisk. L.Simpson: None. G.A.Hansbury: None. N.P.Carbone: None. P.Nigro: None. S.J.Lessard: None. M.Vamvini: None. L.Goodyear: None. Funding National Institutes of Health (K23DK114550 to R.M.), (R01DK112283 to L.G.); Joslin Diabetes Center (T32DK07260-038, 5P30DK36836)

Muscle Quality Index in Morbidly Obesity Patients Related to Metabolic Syndrome Markers and Cardiorespiratory Fitness.

Muscle quality index (MQI) is an emerging health indicator obtained by dividing handgrip strength by body mass index (BMI) that needs to be studied in morbidly obese patients (defined by BMI ≥ 35 kg/m2). To determine the association between MQI, metabolic syndrome (MetS) markers, and cardiorespiratory fitness (CRF), and as a second objective to determine the potential mediation role of MQI in the relationship between abdominal obesity and systolic blood pressure (SBP) in this sample. This cross-sectional study included 86 severely/morbidly obese patients (age = 41.1 ± 11.9 y, nine men). MQI, metabolic syndrome markers, CRF, and anthropometric parameters were measured. Two groups were developed according to MQI; High-MQI (n = 41) and Low-MQI (n = 45). The Low-MQI group reported higher abdominal obesity (High-MQI: 0.7 ± 0.1 vs. Low-MQI: 0.8 ± 0.1 WC/height; p = 0.011), SBP (High-MQI: 133.0 ± 17.5 vs. Low-MQI: 140.1 ± 15.1 mmHg; p = 0.048), and lower CRF (High-MQI; 26.3 ± 5.9 vs. Low-MQI; 22.4 ± 6.1 mL/kg/min, p = 0.003) than the High-MQI group. Waist-to-height ratio (β: -0.07, p = 0.011), SBP (β: -18.47, p = 0.001), and CRF (β: 5.21, p = 0.011) were linked to MQI. In a mediation model, the indirect effect confirms that MQI is a partial mediator of the association between abdominal obesity with SBP. MQI in morbidly obesity patients reported an inverse association with MetS markers and a positive association with CRF (VO2max). It mediates the relationship between abdominal obesity and SBP.

A STUDY TO CORRELATE PULMONARY FUNCTION TEST AND MAXIMUM OXYGEN CONSUMPTION IN HEALTHY YOUNG ADULTS

Relevance. Pulmonary function test (PFT) is an important assessment for lung function. The most commonly used method for PFT is Spirometry. It involves the use of a spirometer to measure lung volumes and capacities. Different diseases cause different patterns of abnormalities in a battery of pulmonary function tests. An earlier study suggested that reductions in maximal oxygen consumption (VO2 max) occur reasonably among patients of obstructive and restrictive lung diseases. &#x0D; Objective of this study was to assess the correlation between the parameters of pulmonary function and cardio-respiratory fitness with the amount of physical activity.&#x0D; Material and Methods. This pilot study was conducted in the Department of Physiology, RUHS College of Medical Sciences, in a group of 100 apparently healthy subjects (students) of 18-25 years age group of either sex. Anthropometric parameters (height, weight and BMI), pulmonary function test (PFT), GPAQ, body fat percentage and VO2 max were assessed in standard laboratory settings.&#x0D; Results. The mean±SD for Age, Height, Weight, GPAQ score, FEV1, PEFR, MVV, FEF25-75% and VO2 max was found to be higher in male participants as compared to female participants while BMI and FVC were almost equal in both the genders but Body Fat % and FEV1/FVC were higher in female participants. Correlation of VO2 max with FVC, FEV1. PEFR, MVV and FEF25-75% is moderately positive while correlation of VO2 max with FEV1/FVC is poorly negative in male subjects. In female subjects correlation of VO2 max with FVC, FEV1. PEFR and MVV is poorly positive while with FEV1/FVC and FEF25-75% it is poorly negative.&#x0D; Conclusion. Present study concludes that maximum oxygen consumption (VO2 max) was positively correlated with pulmonary functions except FEV1/FVC ratio in male. While it was poor positive in females except FEV1/FVC ratio and FEF. Study also concludes that observations of PFT parameters vary for male and female subjects. VO2 max i.e. maximum Oxygen Consumption was found to be higher in male participants of the study as compared to female participant’s i.e. male subjects utilizes more amount of Oxygen while exercising than female subjects.

Health Related Fitness Physical Education Intervention: Self-Determination Perspective

Introduction: The purpose of this study was to investigate the effect of 8-week health-related physical education (HRFPE) intervention on 9th-grade students' health-related fitness knowledge (HRFK) level, physical activity level (PAL), and physical fitness levels. Methods: Experimental research with two groups, HRFPE, and skill-based physical education, with 154 students, was measured before and after the intervention. While the experimental group attended the HRFPE intervention, the comparison group attended the skill-based physical education intervention. Quantitative data were gathered from Health-Related Fitness Knowledge Test (HRFKT), International Physical Activity Questionnaire for Adolescents (IPAQ-A), and Fitnessgram tests (Left &amp; right leg Flexibility, Push-up, Pacer, Curl-up, and BMI). Data gathered from HRFKT, and IPAQ-A were analyzed by mixed-design multivariate analysis of variance (MANOVA). Data from Fitnessgram tests were analyzed by mixed-design analysis of variance (ANOVA). Results: The knowledge test results revealed a significant effect of HRFPE intervention on students' cardiorespiratory fitness, muscular endurance, training principles, and general health knowledge parameters of HRFKT. The intervention significantly increased the low and vigorous PAL of participants. The HRFPE intervention positively affected right leg flexibility, pacer cardiovascular, curl-up muscular endurance, and BMI. Results demonstrated the effect of self-determination theory based HRFPE intervention on developing students' HRFK level, physical activity behavior, and physical fitness test performances. Conclusions: This study revealed that physical education teachers could design and implement HRFPE course interventions in real school settings. Further recommendations were discussed regarding the content and implementation of intervention for physical education teachers, curriculum specialists, and future studies.

Cardiorespiratory fitness, obesity and left atrial function in patients with atrial fibrillation

BackgroundLow cardiorespiratory fitness (CRF) and obesity are related to the development and maintenance of atrial fibrillation (AF). The aim of this study was to determine the association between CRF, obesity and left atrial (LA) mechanical parameters in patients with AF.MethodsA cohort of 154 consecutive paroxysmal and persistent AF patients (Age: 62 ± 10, 26% female) referred for exercise stress testing and transthoracic echocardiography were included. We included patients in sinus rhythm with preserved left ventricular ejection fraction who were able to complete a maximal exercise test. Left atrial strain in the reservoir (LASr), booster (LASb) and conduit (LASc) phases were assessed using dedicated software. LA stiffness, emptying fraction (LAEF) and LA to LV ratio were calculated using previously described formulas.ResultsCRF was positively associated with LAEF (β = 1.3, 95% CI 0.1–2.3, p = 0.02), reservoir (β = 1.5, 95% CI 0.9–2.1, p < 0.001), booster (β = 0.8, 95% CI 0.4–1.2, p < 0.001) and conduit strain (β = 0.7, 95% CI 0.3–1.1, p = 0.001). We observed an inverse association between CRF and both LA stiffness index (β = −0.02, 95% CI (−0.03)–(−0.01), p < 0.001) and LA to LV ratio (β = −0.03, 95% CI (−0.04)–(−0.01), p < 0.001). Obese patients had significantly higher indexed LA volumes compared to overweight and normal BMI patients. The association between obesity and measures of LA function and stiffness did not reach statistical significance.ConclusionAmong AF patients, higher CRF was independently associated with greater LA function and compliance. Obesity was associated with higher LA volumes yet preserved mechanical function.

Associations of Plasma Bioactive Adrenomedullin Levels with Cardiovascular Risk Factors in BRCA1/2 Mutation Carriers

Background Cardiovascular disease (CVD) is an important cause of morbidity and mortality in breast cancer survivors. Effective screening modalities to identify CVD risk are lacking in this population. Adrenomedullin (ADM) has been suggested as a biomarker for subclinical cardiac dysfunction in the general population. Levels of ADM have been proven to be responsive to lifestyle changes that lead to improved cardiovascular health. As BRCA1/2 mutation carriers are deemed to be at an increased risk for CVD, the aim of this study was to examine plasma ADM levels in a cohort of BRCA mutation carriers and to assess their association with cardiovascular risk factors. Methods Plasma ADM concentrations were measured in 292 female BRCA1/2 mutation carriers with and without a history of breast cancer. Subjects were classified into high versus low ADM levels based on the median ADM level in the entire cohort (13.8 pg/mL). Logistic regression models were used to estimate the odds ratios (OR) of having elevated ADM levels by several cardiovascular risk factors. Results Of all women (median age: 43 years), 57.5% had a previous diagnosis of breast cancer. The median time between diagnosis and study entry was three years (range: 0 – 32 years). Women presenting with metabolic syndrome had 22-fold increased odds of having elevated ADM levels (p < 0.001). Elevated ADM levels were associated with lower cardiorespiratory fitness (OR = 0.88, p < 0.001) and several parameters of obesity (p < 0.001). ADM levels were higher in women who have ever smoked (OR = 1.72, p = 0.02). ADM levels were not associated with a previous diagnosis of breast cancer (p = 0.28). Conclusions This is the first study in BRCA mutation carriers that has linked circulating ADM levels to traditional cardiovascular risk factors. The long-term clinical implications of these findings are yet to be determined.

The role of resistance exercise training for improving cardiorespiratory fitness in healthy older adults: a systematic review and meta-analysis.

BackgroundDeclines in cardiorespiratory fitness (CRF) and muscle mass are both associated with advancing age and each of these declines is associated with worse health outcomes. Resistance exercise training (RET) has previously been shown to improve muscle mass and function in the older population. If RET is also able to improve CRF, as it has been shown to do in younger populations, it has the potential to improve multiple health outcomes in the expanding older population.MethodsThis systematic review aimed to identify the role of RET for improving CRF in healthy older adults. A search across CINAHL, MEDLINE, EMBASE and EMCARE databases was conducted with meta-analysis performed on eligible papers to identify improvements in established CRF parameters (VO2 peak, aerobic threshold (AT), 6-minute walking distance test (6MWT) following RET intervention. Main eligibility criteria included older adults (aged over 60), healthy cohorts (disease-specific cohorts were excluded) and RET intervention.ResultsThirty-seven eligible studies were identified. Meta-analysis revealed a significant improvement in VO2 peak (MD 1.89 ml/kg/min; 95% confidence interval (CI) 1.21–2.57 ml/kg/min), AT (MD 1.27 ml/kg/min; 95% CI 0.44–2.09 ml/kg/min) and 6MWT (MD 30.89; 95% CI 26.7–35.08) in RET interventions less than 24 weeks. There was no difference in VO2 peak or 6MWT in interventions longer than 24 weeks.DiscussionThis systematic review adds to a growing body of evidence supporting the implementation of RET in the older population for improving whole-body health, particularly in time-limited timeframes.

Effectiveness of high cardiorespiratory fitness in cardiometabolic protection in prediabetic rats

BackgroundCaloric restriction and exercise are lifestyle interventions that effectively attenuate cardiometabolic impairment. However, cardioprotective effects of long-term lifestyle interventions and short-term lifestyle interventions followed by weight maintenance in prediabetes have never been compared. High cardiorespiratory fitness (CRF) has been shown to provide protection against prediabetes and cardiovascular diseases, however, the interactions between CRF, prediabetes, caloric restriction, and exercise on cardiometabolic health has never been investigated.MethodsSeven-week-old male Wistar rats were fed with either a normal diet (ND; n = 6) or a high-fat diet (HFD; n = 30) to induce prediabetes for 12 weeks. Baseline CRF and cardiometabolic parameters were determined at this timepoint. The ND-fed rats were fed continuously with a ND for 16 more weeks. The HFD-fed rats were divided into 5 groups (n = 6/group) to receive one of the following: (1) a HFD without any intervention for 16 weeks, (2) 40% caloric restriction for 6 weeks followed by an ad libitum ND for 10 weeks, (3) 40% caloric restriction for 16 weeks, (4) a HFD plus an exercise training program for 6 weeks followed by a ND without exercise for 10 weeks, or (5) a HFD plus an exercise training program for 16 weeks. At the end of the interventions, CRF and cardiometabolic parameters were re-assessed. Then, all rats were euthanized and heart tissues were collected.ResultsEither short-term caloric restriction or exercise followed by weight maintenance ameliorated cardiometabolic impairment in prediabetes, as indicated by increased insulin sensitivity, improved blood lipid profile, improved mitochondrial function and oxidative phosphorylation, reduced oxidative stress and inflammation, and improved cardiac function. However, these benefits were not as effective as those of either long-term caloric restriction or exercise. Interestingly, high-level baseline CRF was correlated with favorable cardiac and metabolic profiles at follow-up in prediabetic rats, both with and without lifestyle interventions.ConclusionsShort-term lifestyle modification followed by weight maintenance improves cardiometabolic health in prediabetes. High CRF exerted protection against cardiometabolic impairment in prediabetes, both with and without lifestyle modification. These findings suggest that targeting the enhancement of CRF may contribute to the more effective treatment of prediabetes-induced cardiometabolic impairment.

Effect of Rehydration with Mineral Water on Cardiorespiratory Fitness Following Exercise-Induced Dehydration in Athletes

Background: The aim of the present study was to examine the effect of rehydration with mineral water on cardiorespiratory fitness in athletes. Methods: Twenty athletes (age 21.7 ± 3 years) underwent a random, crossover design experimental trial. Three visits were arranged, with the first for baseline measurement. The second visit included three phases (pre-dehydration, post-dehydration, and post-rehydration), with either Zamzam (mineral water) or bottled water (control water) used. The third visit was similar to the second visit, but with an exchange of the type of water used. Cardiorespiratory fitness and blood parameters were evaluated. Results were compared between Zamzam water and bottled water, and between the phases for each type of water. Results: No significant difference was found between Zamzam and bottled water for the cardiorespiratory fitness markers. However, Zamzam water maintained cardiorespiratory functions including VO2peak, VT1, VT2, and VEpeak, even with rehydration equivalent to 100% of the loss in body weight following exercise-induced dehydration (&gt;2% loss in body weight). Rehydration with bottled water was associated with a significant reduction in both the VO2peak and VEpeak. Conclusions: Rehydration with mineral water such as Zamzam is unlikely to impair cardiorespiratory fitness, even with an intake equal to 100% of the loss in body weight.

Age and Training-Related Changes on Body Composition and Fitness in Male Amateur Cyclists.

Master athletes are considered as a model of healthy aging because they can limit the age-related decline of physiological abilities compared to sedentary individuals. The main objective of this study is to analyze age-related changes and annual training on body composition (BC) and cardiorespiratory fitness (CRF) parameters. The participants in this retrospective cross-sectional study were 176 male cyclists, aged 40–60 years. BC was evaluated through anthropometric measurements and CRF was determined by an incremental cycle ergometer test to exhaustion. A comparative study between age groups was carried out through a one-way ANOVA test and the associations between the variables were assessed by Spearman’s correlation coefficients and multiple regression analysis to estimate the performance. Training was generally associated with a decrease in both body weight and body fat (p < 0.05). A decrease in resting heart rate was observed as a vagal effect of kilometers cycled per year (p < 0.05). Kilometers cycled per year were associated with an increase in peak power output, which was larger in the master 40 group (p < 0.05) with a non-significant upward in VO2max (p > 0.05). In the performance prediction model, the included variables explained 52% of the variance. In summary, the changes induced by age were minimal in BC and negligible in CRF, whereas HR decreased with age. Training load was generally associated with a decrease in body weight, BMI and body fat percentage that was particularly notable in the abdominal skin folds. A decrease in HRrest was observed as a vagal effect due to kilometers cycled per year, and age did not seem to have a significant effect. The annual cycling kilometers were associated with to high PPO that is greater in the M40 group and a non-significant upward trend in VO2max.

Abstract 11236: Preserved Cardiac Reserve and Cardiorespiratory Fitness in Patients with De Novo versus Acute on Chronic HFrEF

Hypothesis: There is limited understanding on the potential differences in the pathophysiology between de-novo heart failure with reduced ejection fraction (HFrEF) and acute on chronic HFrEF. Objective: the aim of this study was to assess differences in cardiorespiratory fitness (CRF) parameters between de-novo heart failure and acute on chronic HFrEF using cardiopulmonary exercise testing (CPX). Methods: We retrospectively analyzed CPX data measured within 2 weeks of discharge following acute hospitalization for HFrEF. The predicted peak oxygen consumption (VO 2 ) was calculated using the FRIEND formula. Circulatory power, a measure of cardiac reserve, was calculated as the product of peak VO 2 and peak systolic blood pressure. Peak O 2 pulse, a surrogate measure of exercise stroke volume, was calculated by dividing peak VO 2 by the maximum heart rate (HR). Left ventricular ejection fraction (LVEF) was calculated using Simpson method during echocardiography. Data are reported as median and interquartile range or frequency and percentage (%). Results: We included 102 patients: 32 (31%) women, 81 (79%) Black, 57.0 [ 51-64] years of age, BMI of 34 [29-39] Kg/m 2 . Of these, 26 (25%) had de-novo HFrEF and 76 (75%) had acute on chronic HFrEF. When compared with acute on chronic, patients with de-novo HFrEF had a significantly higher peak VO 2 (16.5 [12.2-19.4] vs 12.8 [10.15-15.32] mL·kg -1 ·min -1 , p &lt;0.001), %-predicted peak VO 2 (58% [51-75] vs 49% [42-59]) p =0.012), peak HR (134 [117-147] vs 117 [104-136] bpm, p =0.004), peak O 2 pulse (12.2 [10.5 -15.5] vs 9.9 [8.0-13.1] mL/beat, p =0.022) and circulatory power (2823 [1973-3299] vs 1902 [1372-2512] mmHg·mL·kg -1 ·min -1 , p=0.002). No significant difference in resting LVEF was found between groups. Conclusion: Patients with de-novo HFrEF patients have better CRF parameters than those with acute on chronic HFrEF. These differences are not explained by resting left ventricular systolic function but may be related to greater preservation in cardiac reserve during exercise in de-novo HFrEF patients.

HIIT in a treadmill for people with overweight or obesity: a systematic review

AbstractA systematic review was carried out with the objective to analyze the workloads of the high intensity interval training (HIIT) protocols in treadmill, in order to identify the most used intensity percentages, administered in people with overweight or obesity; a bibliographic search was performed in SCOPUS, Web of Science, EBSCO, SCIELO and PUBMED databases. Inclusion criteria were: original experimental studies, where one or more HIIT protocols in treadmill were administered on population with overweight or obesity, regardless their age; studies made in athletes or using functional exercises were excluded. Eight articles were considered for this review from a total of 678 articles detected. All of them reported the administration of HIIT protocols at intensities between 80% and 95% of HRmax, HRpeak, calculated HRmax, or HRreserve; with short (30 seconds) to large (4 minutes) high intensity intervals. It is concluded that HIIT on a treadmill can be used on people with overweight or obesity due to its efficacy and safeness at high intensity levels and can provide optimal results in body composition, cardio respiratory fitness and other parameters such as IL-6 and TNFalpha, in addition to reduce systolic blood pressure. DOI: https://doi.org/10.54167/tecnociencia.v15i1.789

HIIT in a treadmill for people with overweight or obesity: a systematic review

AbstractA systematic review was carried out with the objective to analyze the workloads of the high intensity interval training (HIIT) protocols in treadmill, in order to identify the most used intensity percentages, administered in people with overweight or obesity; a bibliographic search was performed in SCOPUS, Web of Science, EBSCO, SCIELO and PUBMED databases. Inclusion criteria were: original experimental studies, where one or more HIIT protocols in treadmill were administered on population with overweight or obesity, regardless their age; studies made in athletes or using functional exercises were excluded. Eight articles were considered for this review from a total of 678 articles detected. All of them reported the administration of HIIT protocols at intensities between 80% and 95% of HRmax, HRpeak, calculated HRmax, or HRreserve; with short (30 seconds) to large (4 minutes) high intensity intervals. It is concluded that HIIT on a treadmill can be used on people with overweight or obesity due to its efficacy and safeness at high intensity levels and can provide optimal results in body composition, cardio respiratory fitness and other parameters such as IL-6 and TNFalpha, in addition to reduce systolic blood pressure.

Preservation of Cardiac Reserve and Cardiorespiratory Fitness in Patients With Acute De Novo Versus Acute on Chronic Heart Failure With Reduced Ejection Fraction

There is limited understanding on the potential differences in the pathophysiology between de novo heart failure with reduced ejection fraction (HFrEF) and acute on chronic HFrEF. The aim of this study was to assess differences in cardiorespiratory fitness (CRF) parameters between de novo heart failure and acute on chronic HFrEF using cardiopulmonary exercise testing (CPX). We retrospectively analyzed CPX data measured within 2 weeks of discharge following acute hospitalization for HFrEF. Data are reported as median and interquartile range or frequency and percentage (%). We included 102 patients: 32 (31%) women, 81 (79%) black, 57 (51 to 64) years of age, BMI of 34 (29 to 39) Kg/m2. Of these, 26 (25%) had de novo HFrEF and 76 (75%) had acute on chronic HFrEF. When compared with acute on chronic, patients with de novo HFrEF had a significantly higher peak oxygen consumption (VO2) (16.5 [12.2 to 19.4] vs 12.8 [10.1 to 15.3] ml·kg-1·min-1, p <0.001), %-predicted peak VO2 (58% [51 to 75] vs 49% [42 to 59]) p=0.012), peak heart rate (134 [117 to 147] vs 117 [104 to 136] beats/min, p=0.004), peak oxygen pulse (12.2 [10.5 to 15.5] vs 9.9 [8.0 to 13.1] ml/beat, p=0.022) and circulatory power (2,823 [1,973 to 3,299] vs 1,902 [1,372 to 2,512] mm Hg·ml·kg-1·min-1, p=0.002). No significant difference in resting left ventricular ejection fraction was found between groups. In conclusion, patients with de novo HFrEF have better CRF parameters than those with acute on chronic HFrEF. These differences are not explained by resting left ventricular systolic function but may be related to greater preservation in cardiac reserve during exercise in de novo HFrEF patients.

A Pilot Study of Home-Based Exercise and Personalized Nutrition Counseling Intervention in Endometrial Cancer Survivors.

IntroductionTo assess the feasibility of a home-based aerobic exercise and nutrition counseling intervention and effect on cardiorespiratory fitness, cardiovascular disease risk profile, and immune response in obese endometrial cancer survivors.MethodsA longitudinal pilot study assessed a 12-week home-based aerobic exercise and nutrition counseling intervention in obese endometrial cancer survivors. The primary outcome was feasibility defined as 80% adherence to weekly walking sessions calculated among individuals that completed the intervention. Secondary outcomes comprised pre- and post-intervention differences in cardiorespiratory fitness, cardiovascular risk factors, and T-cell function. Descriptive statistics summarized data. Wilcoxon sign tests identified differences between and pre and post-intervention variables.ResultsNineteen women with stage 1 endometrial cancer consented; 9 withdrew and one was a screen failure. Median adherence to weekly walking sessions was 83.3%. Body composition was significantly altered with a reduction in median fat mass from 52.5 kg to 46.9 kg (p=0.04), and BMI from 37.5 kg/m2 to 36.2 kg/m2 (p = 0.004). There was no significant difference in cardiorespiratory fitness or cardiovascular parameters. The percentage of CD4+ and CD8+ T-cells producing IFNγ towards MAGE-A4 significantly increased from and 5.9% to 7.2% (p=0.043) and 13.9% to 14.8% (p=0.046), respectively. There were 3 related adverse events: hip pain, back sprain, and abdominal pain.DiscussionOur home-based exercise and nutrition counseling program was feasible based on 80% adherence to walking sessions and favored altered body composition. However, the discontinuation rate was high and further research is needed to overcome barriers to implementation. Improvement in cardiovascular parameters will most likely require longer and more intensive programs.