Maximal VO2 Research Articles

Non-specific myocardial fibrosis in young competitive athletes: clinical significance and risk prediction by a powerful machine learning-based model.

Non-specific myocardial fibrosis (NSMF) is a heterogeneous entity. We aimed to evaluate young athletes with and without NSMF to establish potentially clinically significance. We analysed data from 328 young athletes. We identified 61 with NSMF and compared them with 75 matched controls. Athletes with NSMF were divided into Group 1 (n = 28) with 'minor' fibrosis and Group 2 (n = 33) with non-insertion point fibrosis, defined as 'major'. Athletes were followed-up for adverse events. Finally, we tested various machine learning (ML) algorithms to create a prediction model for 'major' fibrosis. We created 4 different classifiers. Athletes of black ethnicity were more likely to have a subepicardial pattern (OR: 5.0, p = 0.004). Athletes with 'major' fibrosis demonstrated a higher prevalence of lateral T-wave inversion (TWI) ( < 0.001) and ventricular arrhythmias (VEs > 500/24h, p = 0.046; non-sustained VT, p = 0.043). Athletes with 'minor' fibrosis demonstrated higher right ventricular volumes (p = 0.013), maximum Watts (p = 0.022) and maximum VO2 (p = 0.005). Lateral TWI (p = 0.026) and VO2 < 44mL/min/Kg (p = 0.040) remained the only significant predictors for 'major' fibrosis. During follow up, athletes with 'major' fibrosis were 9.1 times more likely to exhibit adverse events (OR 13.4, p = 0.041). All ML models outperformed the benchmark method in predicting significant MF, best accuracy achieved by the random forest classifier (90%). Lateral TWI and reduced exercise performance are associated with higher burden of fibrosis. Fibrosis was associated with increased ventricular arrhythmia and adverse events. A comprehensive assessment can help develop a ML-based model for significant fibrosis, which could also guide clinical practice and appropriate CMR referrals.

7515 Plasma proteomic signatures for type 2 diabetes mellitus and related traits in the UK Biobank

Abstract Disclosure: T. Gupte: None. Z. Azizi: None. K. Nzenkue: None. P. Kho: None. M. Chen: None. J. Zhou: None. R. Guarischi-Sousa: None. D.J. Panyard: None. F. Abbasi: None. K. Watson: None. S. Clarke: None. P.S. Tsao: None. T.L. Assimes: None. Background: The plasma proteome holds promise as a future diagnostic and prognostic tool that can accurately reflect complex human traits and disease processes. We assessed the ability of plasma proteins to associate with two primary risk factors of type 2 diabetes mellitus (T2DM) and to predict incident T2DM. Methods: Clinical, genetic, and high-throughput proteomic data from three subcohorts of 5586, 5584, and 36339 individuals in the UK Biobank were analyzed for association with DXA-measured truncal fat, maximum VO2, and incident T2DM, respectively. Exclusion criteria included prevalent T2DM, history of T1DM, or elevated A1c (&amp;gt;48 mmol/mol) values. We used LASSO to assess relative ability of 13 clinical variables including the Q-Diabetes (Q-D) score, 36 polygenic risk scores (PRSs), and 2923 proteins to associate with each trait by comparing variances explained (R2) and AUC statistics between data types. Stability selection with randomized LASSO identified the most robustly associated proteins for each trait. The benefit of proteomic signatures (PSs) over the Q-D score was evaluated through the derivation of Δ AUC values. Separate case-control groups were developed to evaluate T2DM prediction in the adiposity and fitness cohorts. Results: Across all three subcohorts, the mean age was 56.6 years, 54.9% were female, and 5.4% developed T2DM over a median follow-up of 7.7 years. In the adiposity cohort, a protein-only LASSO model explained 73.2% of the variance in truncal fat and GLIPR1, CLMP, LEP, FABP4, and FAM3C were among the top proteins selected. In the fitness cohort, a protein-only LASSO model explained 61.9% of the variance in maximum VO2 and LEP, CD99, AGRN, ELN, and CA14 were among the top proteins selected. LASSO-derived PSs increased the R2 of truncal fat and maximum VO2 over clinical and genetic factors by 13% and 1%, respectively, with the former also improving risk prediction of T2DM over Q-D [Δ AUC: 0.026 (95% CI -0.007, 0.060)]. In the T2DM cohort, a protein-only LASSO model returned an AUC of 0.856 (95% CI 0.840, 0.871) and PLXNB2, PODXL, PLA2G7, FGFR2, and NFASC were among the top proteins selected. We observed a similar improvement in T2DM prediction over Q-D [Δ AUC: 0.015 (95% CI 0.009, 0.023)] when using a PS derived strictly from the T2DM outcome and augmented with non-overlapping proteins associated with fat and fitness. A few proteins (ranging between 15-33 for each trait) identified by stability selection algorithms offered most of the improvement in risk prediction. Conclusion: Plasma PS modestly improves the prediction of T2DM over that possible with clinical and genetic factors. Further studies are warranted to better elucidate the clinical utility of these signatures in predicting T2DM risk over the standard practice of using the Q-D score. Presentation: 6/2/2024

Impact of pulmonary rehabilitation on exercise capacity, health-related quality of life, and cardiopulmonary function in lung surgery patients: a retrospective propensity score-matched analysis.

Pulmonary rehabilitation is considered beneficial for patients undergoing lung surgery, yet its specific impacts on exercise capacity, health-related quality of life (HRQL), and cardiopulmonary function require further elucidation. This study aimed to evaluate the effect of PR on these outcomes in patients undergoing lung surgery using a retrospective propensity score-matched analysis. We retrospectively analyzed 420 patients with non-small cell lung cancer (NSCLC) who underwent lung surgery from January 2022 to May 2024. Among these, 84 patients received PR while 336 did not (control group). Propensity score matching (PSM) at a 1:1 ratio yielded 46 patients in each group. Baseline characteristics, spirometry, cardiopulmonary exercise testing, respiratory muscle strength, HRQL, and muscle measurements were assessed pre-and post-surgery. Before PSM, significant differences existed between groups, with the PR group being older and having different pulmonary function baselines. After PSM, groups were well-balanced. Postoperatively, the PR group showed significant improvements in FEV1/FVC (64.17% vs. 50.87%, p < 0.001), FEV1 (2.31 L/min vs. 1.75 L/min, p < 0.001), and predicted FVC percentage (88.75% vs. 68.30%, p < 0.001). Cardiovascular responses showed a lower CI during exercise in the PR group post-PSM (6.24 L/min/m2 vs. 7.87 L/min/m2, p < 0.001). In terms of exercise capacity, the PR group had higher maximal WR percentage (104.76% vs. 90.00%, p = 0.017) and peak VO2 (1150.70 mL/min vs. 1004.74 mL/min, p = 0.009). PR also resulted in less leg soreness and lower total CAT scores postoperatively. Muscle measurements indicated significantly smaller reductions in ΔHUESMCSA and percentage change in the PR group. Pulmonary rehabilitation significantly enhances exercise capacity, HRQL, and cardiopulmonary function in patients undergoing lung surgery. It also mitigates postoperative muscle loss, underscoring its importance in the postoperative management of lung surgery patients.

Distribution of Sports Load by the Smart Photovoltaic Cell Switching System

In order to discuss the allocation effect of anintelligent photovoltaic cell switching system on sports load, thispaper, based on the ZigBee sensing model, designs theinformation allocation module for collecting sports load statusbased on the spectral characteristic analysis of model parametersand the real-time observation of sports load status, and obtainsthe initial data. In-depth analysis of the correlation analysis ofintelligent photovoltaic cell switching system on sports loadallocation, and judge the influence degree of sports loadallocation. The results show that in the monitoring of sports loadstatus, the data acquisition frequency of 28 to 30 kHz can reach -50 dB, and the maximum oxygen uptake VO2, the number ofmax indicators reached 33.21 ± 3.09 and O2, the number of Pindicators is 362.57 ± 98.71, and the number of METs is 9.06 ±1.21. Therefore, we show that the smart photovoltaic cellswitching system has a positive correlation with the sports loaddistribution, and the smart photovoltaic cell switching system hasa practical effect on the sports load distribution.

Chronic UCN2 Administration Alters Muscle Mass, Exercise Metabolism, and Exercise Capacity in Lean Mice

Urocortin 2 (UCN2) is a member of the corticotropin-releasing hormone (CRH) family and an agonist of the G protein-coupled receptor CRH receptor type 2 (CRHR2), which is highly expressed in skeletal muscle but absent from liver in both rodents and humans. UCN2 overexpression or chronic administration increases muscle mass in both lean and diet-induced obese (DIO) mice and is also believed to increase peripheral insulin sensitivity, reminiscent of the effect of acute exercise. However, how these effects of UCN2 may impact muscle function and exercise capacity remain incompletely understood. We hypothesized that treatment with a long term UCN2 treatment would increase lean and muscle mass and improve aerobic exercise capacity in lean, healthy mice. Lean 10-week-old male C57Bl/6J mice completed treadmill acclimatization and an incremental running test to exhaustion to determine maximal running distance and peak oxygen consumption (VO2). Mice were assigned to sedentary or maximal running groups and were treated with UCN2 for 18 days. After the final dose, body composition was assessed by qNMR. Vehicle- and UCN2-treated mice assigned to the maximal running group completed a second maximal test, and immediately upon completion of exercise, blood glucose was measured, and tissues were collected. Blood glucose and tissues were collected from sedentary vehicle- and UCN2-treated mice in the fed state. UCN2 treatment increased food intake, qNMR lean mass, and individual muscle weights. UCN2-treated mice had reduced maximal running distance, peak VO2, and blood glucose in response to exercise compared to vehicle mice. In addition, UCN2-treated mice had reduced hepatic glycogen in both the sedentary and post maximal exercise states. Gastrocnemius muscle from sedentary UCN2-treated mice had increased glycogen content and reduced phosphorylation of glycogen synthase. Following maximal exercise, UCN2-treated mice had higher gastrocnemius glycogen compared to vehicle mice. This indicated similar total glycogen utilization between treatment groups in response to maximal exercise, despite UCN2-treated mice performing less work. Follow-up studies in sedentary mice demonstrated UCN2 dosing increased phosphorylation of proteins involved in insulin-dependent and -independent glucose uptake in gastrocnemius muscle. These findings indicate that UCN2 affects whole-body and muscle substrate utilization and glucose regulation and signaling which results in increased muscle mass and altered exercise capacity. However, the unpredictability of the effects of UCN2 agonism on these parameters requires much further study. This research was funded by Eli Lilly and Company. 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.

Aerobic capacity as an indicator of health

The exercise was carried out to evaluate and classify the level of physical fitness as an indicator of health, to measure the aerobic capacity, which in turn indicates the level of physical fitness. To achieve the objective, The most well-known test in the history of physical education is the Cooper running test, which is a maximum and field test, suitable for all age groups, teenagers, women and men, consists of running for 12 minutes, which refers to enduranceaerobics, which is the ability to tolerate fatigue caused by exercise, managing to maintain the pace and intensity for a long time without a considerable drop in physical performance. The sample consisted of 44 2nd year students, in the 1st academic semester of 2022 at the Escola Superior de Ciências do Desporto (ESCIDE) of the Eduardo Mondlane University (UEM). The main measure for assessing aerobic capacity is maximum oxygen consumption (VO2max=distance-504.1/44.9), which indicates the maximum and integrated capacity of the organism to extract, transport and use oxygen molecules as an energy substrate. The evaluation was carried out on an athletics track with a 400 meter loop. Once the Cooper test was completed, the individual results obtained in the evaluation were compared and using the average health indicator Table 1 of maximum VO2 for running, Table 2 women and Table 3 men, whose classification range is between very poor, poor, sufficient, good, excellent and higher education, resulted in an assessment of the students' physical fitness level as 1 poor, 6 sufficient, 11 good, 12 excellent and 14 superior.

Associations of Skeletal Muscle Mass, Muscle Fat Infiltration, Mitochondrial Energetics, and Cardiorespiratory Fitness With Liver Fat Among Older Adults.

Muscle mass loss may be associated with liver fat accumulation, yet scientific consensus is lacking and evidence in older adults is scant. It is unclear which muscle characteristics might contribute to this association in older adults. We associated comprehensive muscle-related phenotypes including muscle mass normalized to body weight (D3-creatine dilution), muscle fat infiltration (magnetic resonance imaging), carbohydrate-supported muscle mitochondrial maximal oxidative phosphorylation (respirometry), and cardiorespiratory fitness (VO2 peak) with liver fat among older adults. Linear regression models adjusted for age, gender, technician (respirometry only), daily minutes of moderate-to-vigorous physical activity, and prediabetes/diabetes status tested main effects and interactions of each independent variable with waist circumference (high: women-≥88cm, men-≥102cm) and gender. Among older adults aged 75 (interquartile range: 73, 79 years; 59.8% women), muscle mass and liver fat were not associated overall (N = 362) but were positively associated among participants with a high waist circumference (β: 25.2; 95% confidence intervals [95% CI]: 11.7, 40.4; p = .0002; N = 160). Muscle fat infiltration and liver fat were positively associated (β: 15.2; 95% CI: 6.8, 24.3; p = .0003; N = 378). Carbohydrate-supported maximum oxidative phosphorylation (before adjustment) and VO2 peak (after adjustment; β: -12.9; 95% CI: -20.3, -4.8; p = .003; N = 361) were inversely associated with liver fat; adjustment attenuated the estimate for maximum oxidative phosphorylation although the point estimate remained negative (β: -4.0; 95% CI: -11.6, 4.2; p = .32; N = 321). Skeletal muscle-related characteristics are metabolically relevant factors linked to liver fat in older adults. Future research should confirm our results to determine whether trials targeting mechanisms common to liver and muscle fat accumulation are warranted.

High "fitness age" as a risk factor for morbidity and premature mortality.

The level of cardiorespiratory capacity, as measured by maximum VO(2)max oxygen consumption, is a significant factor related to the risk of metabolic syndrome, coronary heart disease and other health disorders. A total cohort of 2901 examinations was divided into 5 groups according to the nature of physical activity: group A - endurance athletes, group B - team sports players, group C - other competitive athletes, group D - recreational leisure-time athletes, group E - people with health problems. Cardiorespiratory fitness was assessed according to the VO(2)max and METmax parameters found in the stress test on a bicycle ergometer. A gradually increased load until exhaustion was used. While in groups A to D cases that would be classified as NYHA 1 (METmax lower than 9) were quite rare (10 cases out of 2777, i.e. 0.3 %), in groups E it was 20 % in men (16 cases out of 82) and 52 % in women (23 cases out of 44) of those examined. Accordingly, fitness age in groups A, B and C generally corresponded to a lower age than the calendar age, in groups E of both men and women, fitness age was significantly higher compared to the calendar age. High fitness age represents a significant risk of morbidity in relation to non-communicable diseases and probably also a significant limitation of their quality of life in later age.

Does Exercise Testing with Arm Crank Ergometer Substitute for Cycle Ergometer to Evaluate Exercise Capacity?

Using the upper limbs to test cardiopulmonary exercise can be a useful option in the case of individuals who are unable to pedal a bicycle due to lower limb injury or disability. We evaluated whether exercise testing with the upper limbs can be used equivalently to that of the lower limbs in assessing exercise capacity. Nine collegiate rowers and eight collegiate cyclists underwent incremental exercise testing with an arm crank ergometer (ACE) and cycle ergometer (CE). Heart rate (HR) and oxygen uptake (VO2) were monitored throughout the tests. Segmental muscle mass and flow-mediated dilation of brachial artery were measured to assess the training status of the upper limbs. The muscle mass of the brachium, upper limb, and trunk were greater in the rowers than in the cyclists (p &lt; 0.05). The correlations between HR and VO2 was significantly different depending on exercise modalities, ACE and CE, in both groups (p &lt; 0.001). The estimated maximal VO2 using the correlation formula and age-predicted maximal HR was significantly lower in the exercise testing group with ACE than in the group with CE in rowers and cyclists (41.7 ± 7.3 vs. 52.6 ± 8.6 mL/kg/min, p = 0.010 and 35.5 ± 14.2 vs. 50.4 ± 13.4 mL/kg/min, p = 0.011, respectively). The results suggested that exercise capacity assessed by exercise testing with ACE is underestimated, regardless of the training status of the upper limbs. Further research is needed to verify factors which affect the correlations between HR and VO2 during upper- and lower-limb exercise.

Surveillance cardiopulmonary exercise testing can risk-stratify childhood cancer survivors: underlying pathophysiology of poor exercise performance and possible room for improvement

BackgroundAsymptomatic childhood cancer survivors (CCS) frequently show decreased exercise performance. Poor exercise performance may indicate impaired future cardiovascular health.MethodsCardiopulmonary exercise testing (CPET) was performed in asymptomatic off-treatment CCS (age ≥ 10 years). Patients were divided into Normal and Poor performance groups by %predicted maximum VO2 at 80%. Both peak and submaximal CPET values were analyzed.ResultsThirty-eight males (19 Normal, 19 Poor) and 40 females (18 Normal, 22 Poor) were studied. Total anthracycline dosage was comparable among 4 groups. The body mass index (BMI), although normal, and weight were significantly higher in Poor groups. Peak heart rate (HR) and peak respiratory exchange ratio (RER) were comparable in all four groups. Peak work rate (pWR)/kg, peak oxygen consumption (pVO2)/kg, peak oxygen pulse (pOP)/kg, and ventilatory anaerobic threshold (VAT)/kg were significantly lower, whereas heart rate (HR) increase by WR/kg (ΔHR/Δ[WR/kg] was significantly higher in Poor groups. Simultaneously plotting of weight & pVO2 and ΔHR/ΔWR & ΔVO2/ΔHR revealed a distinct difference between the Normal and Poor groups in both sexes, suggesting decreased skeletal muscle mass and decreased stroke volume reserve, respectively, in Poor CCS. The relationship between VAT and pVO2 was almost identical between the two groups in both sexes. Ventilatory efficiency was mildly diminished in the Poor groups.ConclusionsDecreased skeletal muscle mass, decreased stroke volume reserve, and slightly decreased ventilatory efficiency characterize Poor CCS in both sexes. This unique combined CPET analysis provides useful clinical biomarkers to screen subclinical cardiovascular abnormality in CCS and identifies an area for improvement.

Effects of Eight Week High-Intensity Interval Training Program Followed by a Six Week Detraining on Healthy Adult Gym-Users

Background: The literature has reported that high-intensity training (HIIT) can effectively improve maximum oxygen uptake (VO2 max) and body composition (BC). Still, contradictory results are reported regarding its impact of HIIT training and post-period detraining on gym users. Objective: This study aimed to verify how eight weeks of HIIT affects VO2 maximum and BC in healthy gym users. Additionally, the effect of a six-week detraining period was verified. A group of 10 gym-users (mean ± SD age: 29.03 ± 6.18 years) volunteered for this randomized controlled trial (RCT). Method: A HIIT program that included exercises such as jumping air squats, burpees and jumping jacks was applied over eight weeks. After this period, a six-week detraining period was applied. To measure changes in VO2 max, the Queen’s College Step Test (QCST) was applied, while a bioimpedance scale was used to measure BC. Results: Eight weeks of HIIT seem to show a tendency to increase VO2 max and cause positive changes in BC (p ≤ 0.05) with the exception of two variables (i.e., fat-free mass and fat mass). Furthermore, the results suggest that 6 weeks of detraining may negatively affect gains resulting from the training program, particularly in VO2 max and body mass index (BMI) p ≥ 0.05. Conclusions: Eight-week HIIT program incorporating short-duration explosive exercises can positively affect VO2 max and BC in adult gym users.

Architecture of urchin-like TiO2 integrated ultrasmall Rh nanoparticles with oxygen vacancy-reinforced electronic metal-support interaction for boosting hydrogen production from ammonia borane hydrolysis

Metal oxide-supported Rh nanoparticles (NPs) can provide abundant catalytically active sites for hydrogen evolution from ammonia borane hydrolysis (ABH). Considering the scarcity and high cost, developing effective strategies to reduce the utilization of Rh and simultaneously improving its catalytic activity is absolutely needed. Here, we develop ultrafine Rh NPs anchored on oxygen vacancies (VO)-bearing urchin-like TiO2 (U-TiO2). VO can facilitate the formation of electron-rich metallic Rh surface and boost the H2O dissociation, leading to highly efficient hydrogen generation from ABH without alkali promoters. Noticeably, the temperature-controlled annealing of the Rh/U-TiO2 precursor at 450 °C in reducing atmosphere generates the maximum VO concentration. This arouses strong electronic metal-support interaction between the Vo and Rh NPs to yield electron-rich metallic Rh surface. The obtained Rh/UT-450Vo exhibits a high initial turnover frequency of 1729 min−1 for ABH without alkali promoters, outperforming that of the contrast samples and most of previously developed Rh catalysts. This finding offers an effective strategy to fabricate high-efficiency metal oxide-supported metal NPs toward catalytic hydrogen production.

Ventilatory efficiency in post-COVID-19 athletes.

Limitation in exercise capacity has not been described in athletes affected by SARS-CoV-2 infection. However, patients who have recovered from COVID-19 without cardiopulmonary impairment show exaggerated ventilatory response during exercise. Therefore, we aimed to evaluate the ventilatory efficiency (VEf) in competitive athletes recovered from COVID-19 and to characterize the ventilation versus carbon dioxide relationship (VE/VCO2 ) slope in this population. Thirty-seven competitive athletes with COVID-19 were recruited for this study. All participants underwent spirometry, echocardiography, and cardiopulmonary exercise testing (CPET). z-FVC values and end-title pressure of CO2 (PET CO2 ) were lower in the third tertile compared with the first tertile: -0.753 ± 0.473 vs. 0.037 ± 0.911, p = 0.05; 42.2 ± 2.7 vs. 37.1 ± 2.5 mmHg, p < 0.01. VE/VCO2 slope was significantly correlated to maximal VCO2 /VE and maximal VO2 /VE: coefficient = -0.5 R2 = 0.58, p < 0.0001 and coefficient = -0.3 R2 = 0.16, p = 0.008. Competitive athletes affected by SARS-CoV-2 infection, without cardio-respiratory disease sequel, may present ventilatory inefficiency (ViE), without exercise capacity limitation. FVC is higher in athletes with better ventilatory performance during exercise, and increased VE/VCO2 slope is inversely correlated to max VCO2 /VE and max VO2 /VE.

HUBUNGAN BENTUK TELAPAK KAKI FLAT FEET DENGAN VO2 MAKS PADA ATLET PENCAK SILAT TINGKAT PROVINSI DKI JAKARTA BERDASARKAN LAMA LATIHAN

Flat feet can cause a reduction in the foot function resulting in fatigue when walking or running. This condition can result in a suboptimal intensity exercise required to improve VO2Max of Pencak Silat athletes. This study aimed to determine the relationship between the shape of foot and VO2Max based on training duration among Pencak Silat athletes at the provincial level of DKI Jakarta. The study used a cross-sectional design involving 46 athletes selected through a total sampling. The subject criteria for this study included athletes aged 17-24 years, healthy, and had no lower extremities problems. The study utilized footprint test and multistage fitness test instruments. The study found that 27 (58.7%) athletes had a normal foot shape, while 19 (41.3%) had flat feet. There were no differences in age, sex, body mass index, and training duration between the two groups of foot shape (p 0.05). The maximum VO2 value was 45.0 (7.2) ml/kg/min in athletes with normal foot shape and 40.1 (70.5) ml/kg/min in athletes with flat feet. The independent t-test revealed a significant difference in VO2Max between the two groups of foot shapes (p = 0.028). The increase of VO2Max was in line with the duration of exercise, but this increase was not significant in subjects with flat feet compared to those with normal foot shape. It concludes that flat feet are negatively associated with VO2Max of athletes. Pencak Silat athletes with flat feet must exert extra effort to enhance their VO2Max, such as interval training and kinesio taping. Further research is recommended to explore the impact of these efforts on improving VO2Max.

Heart Rate Reserve and VO2 Reserve Are Not Interchangeable During Prolonged Exercise

Abstract Background Percentages of heart rate reserve (%HRR) and oxygen consumption reserve (%VO2R) provide equivalent intensities during incremental exercise. These percentages increase during prolonged exercise at a constant workload, and it is unclear if they increase to a similar degree. In this study, we tested whether %HRR and %VO2R maintain equivalency during prolonged exercise at a constant workload. Methods Fifteen males and 12 females participated in an incremental cycle ergometer test to determine maximum VO2. They then performed 2 prolonged exercise trials, 1 for 30 min at a vigorous-intensity workload corresponding with 60% VO2R, and 1 for 60 min at a moderate-intensity workload of 40% VO2R. HR and VO2 were measured continuously, and %HRR and %VO2R were reported every 5 min. A fan and consumption of cold water were used to minimize heat stress. Results Both %HRR and %VO2R increased during constant-workload exercise (P &amp;lt; 0.001), and %HRR increased significantly more than %VO2R (P &amp;lt; 0.001). Females exhibited greater %HRR than %VO2R beginning at 10 min into both trials (P &amp;lt; 0.05), while %HRR exceeded %VO2R for males beginning at 15 min of the 30-min trial (P &amp;lt; 0.05) and at 30 min of the 60-min trial (P &amp;lt; 0.05). HRR values for females were significantly greater than those for males at most time points (P &amp;lt; 0.05). Conclusion: During prolonged, constant-workload exercise, cardiovascular drift results in a greater increase in %HRR than %VO2R, and this is more pronounced in females than males.

Differences in Vo2 Maximum Value Post Resistance Exercises Between Male and Female

Differences in Vo2 Maximum Value Post Resistance Exercises Between Male and Female

Physiological and Energetic Demands During Still-Rings Routines of Elite Artistic Gymnasts.

The aim of the study was to analyze physiological and energetic demands of elite gymnasts during still-rings routines (SRRs). Eleven male gymnasts (mean [SD] 23.6 [3.9]y, 65.9 [5.6]kg, 171.1 [6.7]cm) performed a maximal graded exercise test and an individual SRR, during which respiratory gas and heart rate (HR) were measured using a mobile spiroergometer and a paired HR sensor. Metabolic energy and the energy contribution in terms of aerobic, anaerobic lactic, and anaerobic alactic were determined by oxygen uptake (VO2) during exercise, net lactate production, and the fast component of postexercise VO2 kinetics. Mean routine duration of the SRRs was 48.3 (4.5)seconds. VO2 and HR during SRRs were shown to be 86.9% (5.9%) and 91.0% (3.3%), respectively, of the maximal values measured during the graded exercise test. The anaerobic alactic, aerobic, and anaerobic lactic systems provided 50.9% (6.6%), 28.6% (4.8%), and 20.5% (5.2%), respectively, of the total energy required during SRRs. The energy contribution of the anaerobic lactic system correlated negatively with individual anaerobic threshold (r = -.715) and maximal VO2 (r = -.682). The anaerobic alactic system is the predominant energy source for ATP resynthesis during SRRs. The high relative VO2 and HR values reached during SRRs showthat these routines strongly stress the cardiovascular system.

Cardiopulmonary exercise testing and heart failure: a tale born from oxygen uptake.

Since 50 years, cardiopulmonary exercise testing (CPET) plays a central role in heart failure (HF) assessment. Oxygen uptake (VO2) is one of the main HF prognostic indicators, then paralleled by ventilation to carbon dioxide (VE/VCO2) relationship slope. Also anaerobic threshold retains a strong prognostic power in severe HF, especially if expressed as a percent of maximal VO2 predicted value. Moving beyond its absolute value, a modern approach is to consider the percentage of predicted value for peak VO2 and VE/VCO2 slope, thus allowing a better comparison between genders, ages, and races. Several VO2 equations have been adopted to predict peak VO2, built considering different populations. A step forward was made possible by the introduction of reliable non-invasive methods able to calculate cardiac output during exercise: the inert gas rebreathing method and the thoracic electrical bioimpedance. These techniques made possible to calculate the artero-venous oxygen content differences (ΔC(a-v)O2), a value related to haemoglobin concentration, pO2, muscle perfusion, and oxygen extraction. The role of haemoglobin, frequently neglected, is however essential being anaemia a frequent HF comorbidity. Finally, peak VO2 is traditionally obtained in a laboratory setting while performing a standardized physical effort. Recently, different wearable ergo-spirometers have been developed to allow an accurate metabolic data collection during different activities that better reproduce HF patients' everyday life. The evaluation of exercise performance is now part of the holistic approach to the HF syndrome, with the inclusion of CPET data into multiparametric prognostic scores, such as the MECKI score.

Incidence and risk factors of late right heart failure in chronic mechanical circulatory support.

Late right heart failure (LRHF) is a common complication during long-term left ventricular assist device (LVAD) support. We aimed to identify risk factors for LRHF after LVAD implantation. Patients undergoing primary LVAD implantation between 2006 and 2019 and surviving the perioperative period were included for this study (n = 261). Univariate Cox proportional hazards analysis was used to assess the association of clinical covariates and LRHF, stratified for device type. Variables with p < 0.10 entered the multivariable model. In a subset of patients with complete echocardiography or right catheterization data, this multivariable model was extended. Postoperative cardiopulmonary exercise test data were compared in patients with and without LRHF. Nineteen percentage of patients suffered from LRHF after a median of 12 months, of which 67% required hospitalization. A history of atrial fibrillation (AF) (HR: 2.06 [1.08-3.93], p = 0.029), a higher preoperative body mass index (BMI) (HR: 1.07 [1.01-1.13], p = 0.023), and intensive care unit (ICU) duration (HR: 1.03 [1.00-1.06], p = 0.025) were independent predictors of LHRF in the multivariable model. A significant relation between the severity of tricuspid regurgitation (TR) and LRHF (HR: 1.91 [1.13-3.21], p = 0.016) was found in patients with echocardiographic data. Patients with LRHF demonstrated a lower maximal workload and peak VO2 at 6 months postoperatively. A history of AF, BMI, and longer ICU stay may help identify patients at high risk for LRHF. Severity of TR was significantly related to LRHF in a subset of patients.

Physiological and biomechanical responses to exercise on two different types of rowing ergometers in NCAA Division I oarswomen.

Stationary (SE) and dynamic (DE) rowing ergometers, that are utilized for indoor training and physical assessment of competitive rowers, may elicit different physiological and biomechanical responses. The present study used SE and DE ergometers to examine submaximal and peak physiological and biomechanical responses during an incremental rowing test. Twelve National Collegiate Athletic Association (NCAA) Division I oarswomen performed seven-stage rowing tests with the last stage performed with maximal effort. Heart rate (HR), lactate (LA), oxygen uptake (VO2), ventilation (VE), stroke rate (SR), gross efficiency (GE), and rating of perceived exertion (RPE) were obtained; while trunk, hip, knee, shoulder, and elbow ranges of motion (ROM) were measured. SR was higher at maximal stage DE (29.3 vs. 34.8 strokes/min, p = 0.018, d = 1.213). No difference occurred in responses of maximal stage HR, RPE, VO2, VE, LA, or GE between the two ergometers. Submaximal LA and SR were greater on the DE for all submaximal stages. Submaximal VE was greater on the DE for all submaximal stages except Stage 3 (p = 0.160, d = 0.655). VO2 was higher on the DE Stages 2-5. GE was higher on the SE for Stages 2-5. Athletes showed increased trunk (p = 0.025, [Formula: see text] = 0.488) and knee (p = 0.004, [Formula: see text] = 0.668) ROM on SE. Rowing on the DE appears to elicit a greater stroke rate and more optimal joint angles especially at high intensities. Hence, the DE is worthy of consideration as a preferred ergometer for women rowers.