Mean Peak VO2 Research Articles

Inspiratory Muscle Function and Exercise Capacity in Patients With Heart Failure With Preserved Ejection Fraction

BackgroundHeart failure with preserved ejection fraction (HFpEF) is a clinical syndrome characterized by impaired exercise capacity resulting from dyspnea and fatigue. The pathophysiological mechanisms underlying the exercise intolerance in HFpEF are not well established. We sought to evaluate the effects of inspiratory muscle function on exercise tolerance in symptomatic patients with HFpEF. Methods and ResultsA total of 74 stable symptomatic patients with HFpEF and New York Heart Association class II-III underwent a cardiopulmonary exercise test between June 2012 and May 2016. Inspiratory muscle weakness was defined as maximum inspiratory pressure (MIP) <70% of normal predicted values. Pearson correlation coefficient and multivariate linear regression analysis were used to assess the association between percent of predicted MIP (pp-MIP) and maximal exercise capacity [measured by peak oxygen uptake (peak VO2) and percent of predicted peak VO2 (pp-peak VO2)]. Thirty-one patients (42%) displayed inspiratory muscle weakness. Mean (standard deviation) age was 72.5 ± 9.1 years, 53% were women, and 35.1% displayed New York Heart Association class III. Mean peak VO2 and pp-peak VO2 were 10 ± 2.8 mL•min•kg and 57.3 ± 13.8%, respectively. The median (interquartile range) of pp-MIP was 72% (58%–90%). pp-MIP was not correlated with peak VO2 (r = −0.047, P = .689) nor pp-peak VO2 (r = −0.078, P = .509). Furthermore, in multivariable analysis, pp-MIP showed no association with peak VO2 (β coefficient = 0.01, 95% confidence interval −0.01 to 0.03, P = .241) and pp-peak VO2 (β coefficient = −0.00, 95% confidence interval −0.10 to 0.10, P = .975). ConclusionsIn symptomatic elderly patients with HFpEF, we found that pp-MIP was not associated with either peak VO2 or pp-peak VO2.

Individual variations in nitric oxide synthase-dependent sweating in young and older males during exercise in the heat: role of aerobic power.

We evaluated the association between aerobic power (defined by peak oxygen consumption; VO 2peak) and the contribution of nitric oxide synthase (NOS) to the sweating response in young and older individuals during exercise in the heat. Data from 44 young (24 ± 1 years) and 48 older (61 ± 2 years) males with mean VO 2peak of 47.8 ± 2.4 (range, 28.0–62.3) and 39.1 ± 2.3 (range, 26.4–55.7) mLO 2 kg−1 min−1, respectively, were compiled from our prior studies. Participants performed two 15‐ to 30‐min bouts of exercise at a fixed rate of metabolic heat production of 400 or 500 W, each separated by 15–20 min recovery in the heat (35°C, relative humidity of 20%). Forearm sweat rate (ventilated capsule technique) was measured at two skin sites that were continuously and simultaneously administered with lactated Ringers solution (Control) or 10 mmol/L NG‐nitro‐L‐arginine methyl ester (L‐NAME, nonselective NOS inhibitor) via intradermal microdialysis. Sweat rate during the final 5 min of each exercise bout was lower with L‐NAME compared to the Control in both groups (all P < 0.05). The magnitude of the attenuation in sweat rate induced by L‐NAME compared to the Control was not correlated with VO 2peak (all P ≥ 0.46) while this attenuation was negatively correlated with the sweat rate at the Control in both groups and in both exercise bouts (all P < 0.01, R ≤ −0.43). These results suggest that NOS‐dependent sweating is not associated with aerobic power per se, while it becomes evident in individuals who produce larger sweat rates during exercise irrespective of age.

Mitral systolic velocity at peak exercise predicts impaired exercise capacity in patients with heart failure with preserved ejection fraction.

Nearly half of patients with heart failure have normal left ventricular ejection fraction (LVEF), but their prognosis is no better than those with reduced LVEF. Although peak oxygen consumption (VO2 ) is an independent predictor of mortality in heart failure, it is unclear how cardiac function during exercise contributes to peak VO2 . Therefore, we explored the useful parameters measured by exercise stress echocardiography to predict peak VO2 in patients with heart failure with preserved LVEF (HFpEF). We assessed 80 patients being investigated for effort intolerance or dyspnea and finally analyzed 50 patients who satisfied the HFpEF criteria. Mean peak VO2 was 16.4±2.8mL/kg/min. Twenty-three patients (46.0%) achieved a peak VO2 <16.0mL/kg/min (Weber class C or D). There was a significant relationship between mitral systolic velocity (S') and cardiac output (CO) at rest (R=.55, P<.0001) and peak exercise (R=.64, P<.0001). The absolute increase in S' from rest to peak exercise also correlated with the absolute increase in CO (R=.32, P=.02). Multivariate logistic regression analysis showed that S' at peak exercise independently predicted peak VO2 . Receiver-operator characteristic curve analysis identified that an S' at peak exercise of ≤8.13cm/s predicted a peak VO2 <16.0mL/kg/min (sensitivity 95.7%, specificity 44.4%, area under curve 0.70, 95% confidence interval 0.55-0.84, P=.004). Mitral systolic velocity at peak exercise accurately reflects peak VO2 and may facilitate stratification of risk in patients with HFpEF.

Cardiorespiratory Fitness after Transient Ischemic Attack and Minor Ischemic Stroke: Baseline Data of the MoveIT Study

Cardiorespiratory fitness (CRF) is reduced in patients with stroke. It is unclear whether it is also reduced in patients with a transient ischemic attack (TIA) or minor stroke. We investigated the CRF in patients with a recent TIA or minor stroke and explored which determinants are associated with a lower fitness. In 113 patients with a recent TIA or minor ischemic stroke (64 (SD = 10) years of age; 49 (IQR 27-86) days post TIA or stroke), the peak oxygen consumption (VO2peak) was determined in a symptom-limited ramp exercise test. Physical activity level, vascular risk factors, history of vascular or pulmonary disease, and stroke characteristics were recorded at inclusion and related to the VO2peak. Mean VO2peak was 22 mL/kg/min (SD = 6), which is the fifth percentile of age- and sex-related normative values. Increasing age and female sex were associated with a lower VO2peak (B (95% CI): per 10 years -2.57 mL/kg/min (-3.75; -1.40) and female sex -5.84 mL/kg/min (-8.06; -3.62)). Age- and sex-adjusted linear regression analyses showed that a history of cardiovascular disease and pulmonary disease was associated with a lower VO2peak. In addition, a lower level of physical activity, hypertension, smoking, and overweight were associated with a lower VO2peak. History of stroke and stroke characteristics were not related to VO2peak. The majority of patients with a recent TIA or minor ischemic stroke have a poor CRF. Our findings suggest that premorbid cardiovascular and pulmonary disease and vascular risk factors, but not TIA- or stroke-related factors, contribute to a reduced CRF.

Association Between Liver Function and Peak Oxygen Uptake in Heart Failure Patients: A Retrospective Observational Study.

With respect to liver function and heart failure, 46% of acute decompensated heart failure patients exhibit abnormal liver function. However, there have been no reports of the association between liver function and functional capacity in these patients. Our aim was to clarify the relationship between liver function and functional capacity using the peak oxygen uptake (VO2). We retrospectively identified 36 heart failure patients who were referred to our rehabilitation laboratory. These patients underwent cardiopulmonary exercise testing (CPX). Furthermore, we investigated the correlations between peak VO2, blood measurements [e.g., total bilirubin (T-bil) and brain natriuretic peptide], and echocardiographic parameters. Finally, multivariate regression analysis was performed to investigate the independent variables related to peak VO2. The mean peak VO2 was 10.7±2.9 ml/kg/min. Peak VO2 during CPX correlated inversely with T-bil [r=-0.379, 95% confidence intervals (CI): -0.654 to -0.014, P=0.043], aspartate transaminase (r=-0.426, 95% CI: -0.685 to -0.07, P=0.021), and peak heart rate (r=0.391, 95% CI: 0.029 to 0.663, P=0.036). The significant independent factors associated with peak VO2 were treatment with statin (β=-3.19, P=0.015) and T-bil levels (β=-4.27, P=0.002). Our findings demonstrated that liver function may contribute to the functional capacity in heart failure patients.

Cardiopulmonary exercise testing in children with cystic fibrosis: one centre's experience

BackgroundWhile exercise testing is increasingly used as a prognostic indicator in cystic fibrosis (CF), it is reported to be underused in UK CF centres, particularly in children. Here, we evaluated...

The six-minute walk test predicts cardiorespiratory fitness in individuals with aneurysmal subarachnoid hemorrhage

Background: Peak oxygen uptake (VO2peak) established during progressive cardiopulmonary exercise testing (CPET) is the “gold-standard” for cardiorespiratory fitness. However, CPET measurements may be limited in patients with aneurysmal subarachnoid hemorrhage (a-SAH) by disease-related complaints, such as cardiovascular health-risks or anxiety. Furthermore, CPET with gas-exchange analyses require specialized knowledge and infrastructure with limited availability in most rehabilitation facilities.Objectives: To determine whether an easy-to-administer six-minute walk test (6MWT) is a valid clinical alternative to progressive CPET in order to predict VO2peak in individuals with a-SAH.Methods: Twenty-seven patients performed the 6MWT and CPET with gas-exchange analyses on a cycle ergometer. Univariate and multivariate regression models were made to investigate the predictability of VO2peak from the six-minute walk distance (6MWD).Results: Univariate regression showed that the 6MWD was strongly related to VO2peak (r = 0.75, p < 0.001), with an explained variance of 56% and a prediction error of 4.12 ml/kg/min, representing 18% of mean VO2peak. Adding age and sex to an extended multivariate regression model improved this relationship (r = 0.82, p < 0.001), with an explained variance of 67% and a prediction error of 3.67 ml/kg/min corresponding to 16% of mean VO2peak.Conclusions: The 6MWT is an easy-to-administer submaximal exercise test that can be selected to estimate cardiorespiratory fitness at an aggregated level, in groups of patients with a-SAH, which may help to evaluate interventions in a clinical or research setting. However, the relatively large prediction error does not allow for an accurate prediction in individual patients.

How Accurate Is the Prediction of Maximal Oxygen Uptake with Treadmill Testing?

BackgroundCardiorespiratory fitness measured by treadmill testing has prognostic significance in determining mortality with cardiovascular and other chronic disease states. The accuracy of a recently developed method for estimating maximal oxygen uptake (VO2peak), the heart rate index (HRI), is dependent only on heart rate (HR) and was tested against oxygen uptake (VO2), either measured or predicted from conventional treadmill parameters (speed, incline, protocol time).MethodsThe HRI equation, METs = 6 x HRI– 5, where HRI = maximal HR/resting HR, provides a surrogate measure of VO2peak. Forty large scale treadmill studies were identified through a systematic search using MEDLINE, Google Scholar and Web of Science in which VO2peak was either measured (TM-VO2meas; n = 20) or predicted (TM-VO2pred; n = 20) based on treadmill parameters. All studies were required to have reported group mean data of both resting and maximal HRs for determination of HR index-derived oxygen uptake (HRI-VO2).ResultsThe 20 studies with measured VO2 (TM-VO2meas), involved 11,477 participants (median 337) with a total of 105,044 participants (median 3,736) in the 20 studies with predicted VO2 (TM-VO2pred). A difference of only 0.4% was seen between mean (±SD) VO2peak for TM- VO2meas and HRI-VO2 (6.51±2.25 METs and 6.54±2.28, respectively; p = 0.84). In contrast, there was a highly significant 21.1% difference between mean (±SD) TM-VO2pred and HRI-VO2 (8.12±1.85 METs and 6.71±1.92, respectively; p<0.001).ConclusionAlthough mean TM-VO2meas and HRI-VO2 were almost identical, mean TM-VO2pred was more than 20% greater than mean HRI-VO2.

Adrenergic Receptor Polymorphism and Maximal Exercise Capacity after Orthotopic Heart Transplantation.

BackgroundMaximal exercise capacity after heart transplantion (HTx) is reduced to the 50–70% level of healthy controls when assessed by cardiopulmonary exercise testing (CPET) despite of normal left ventricular function of the donor heart. This study investigates the role of donor heart β1 and β2- adrenergic receptor (AR) polymorphisms for maximal exercise capacity after orthotopic HTx.MethodsCPET measured peak VO2 as outcome parameter for maximal exercise in HTx recipients ≥9 months and ≤4 years post-transplant (n = 41; mean peak VO2: 57±15% of predicted value). Donor hearts were genotyped for polymorphisms of the β1-AR (Ser49Gly, Arg389Gly) and the β2-AR (Arg16Gly, Gln27Glu). Circumferential shortening of the left ventricle was measured using magnetic resonance based CSPAMM tagging.ResultsPeak VO2 was higher in donor hearts expressing the β1-Ser49Ser alleles when compared with β1-Gly49 carriers (60±15% vs. 47±10% of the predicted value; p = 0.015), and by trend in cardiac allografts with the β1-AR Gly389Gly vs. β1-Arg389 (61±15% vs. 54±14%, p = 0.093). Peak VO2 was highest for the haplotype Ser49Ser-Gly389, and decreased progressively for Ser49Ser-Arg389Arg > 49Gly-389Gly > 49Gly-Arg389Arg (adjusted R2 = 0.56, p = 0.003). Peak VO2 was not different for the tested β2-AR polymorphisms. Independent predictors of peak VO2 (adjusted R2 = 0.55) were β1-AR Ser49Gly SNP (p = 0.005), heart rate increase (p = 0.016), and peak systolic blood pressure (p = 0.031). Left ventricular (LV) motion kinetics as measured by cardiac MRI CSPAMM tagging at rest was not different between carriers and non-carriers of the β1-AR Gly49allele.ConclusionSimilar LV cardiac motion kinetics at rest in donor hearts carrying either β1-AR Gly49 or β1-Ser49Ser variant suggests exercise-induced desensitization and down-regulation of the β1-AR Gly49 variant as relevant pathomechanism for reduced peak VO2 in β1-AR Gly49 carriers.

Physical and functional follow-up of tuberculosis patients in initial intensive phase of treatment in Cameroon using the 6-min walk test.

This study aimed to evaluate functional capacities of Cameroonian tuberculosis (TB) patients in initial intensive phase of treatment using the 6-min walk test (6MWT) and to compare them to an age-matched healthy group. Twenty-eight TB patients newly diagnosed and 19 healthy age-matched peoples participated in the study. Performance parameters were determined using the 6MWT. Anthropometric and cardiorespiratory parameters were measured at baseline and after 6MWT. Two months later, TB patients were submitted to the same evaluation. We found significant differences in anthropometric parameters between the two groups. The baseline cardiorespiratory parameters and performance characteristics of TB patients were lower than control group (571.7±121.0 m vs 841.6±53.0 m, P<0.0001 for 6-min walk distance (6MWD) and 18.1±2.8 mL/kg/min vs 24.3±1.2 mL/kg/min, P<0.001 for mean VO2 peak (peak oxygen consumption). Two months after, significant improvements were noted in anthropometric, cardiorespiratory and performance parameters except for bone mass and FEV1/FEV6 (forced expiratory volumes in 1 second/6 seconds) ratio. Significant correlations were found between the 2-min walked distance (P<0.0001, r=0.95), 4-min walked distance (P<0.0001, r=0.97) and 6MWD. In conclusion, TB patients have impaired physical functional capacity but they improved after 2 months of treatment. 6MWT can be a useful tool in the assessment of physical parameters and cardiorespiratory functional capacity rehabilitation of TB patients during the treatment.

Effects of eHealth physical activity encouragement in adolescents with complex congenital heart disease: The PReVaiL randomized clinical trial

ObjectiveTo assess benefit and harms of adding an eHealth intervention to health education and individual counseling in adolescents with congenital heart disease. DesignRandomized clinical trial. SettingDenmark. PatientsA total of 158 adolescents aged 13–16years with no physical activity restrictions after repaired complex congenital heart disease. InterventionsPReVaiL consisted of individually tailored eHealth encouragement physical activity for 52weeks. All patients received 45min of group-based health education and 15min of individual counseling involving patients' parents. OutcomesThe primary outcome was maximal oxygen uptake (VO2 peak) at 52weeks after randomization. The secondary outcome was physical activity. Exploratory outcomes were generic and disease-specific questionnaires. ResultsIn the intervention group, 58 patients (72%) completed the final test, but of those, only 46 (57%) fulfilled the compliance criteria of using the eHealth application for at least 2 consecutive weeks. In the control group, 61 patients (79%) completed both exercise tests. Adjusted for baseline values, the difference between the intervention group and the control group in mean VO2 peak at 1year was −0.65ml·kg−1·min−1 (95% CI −2.66 to 1.36). Between-group differences at 1year in physical activity, generic health-related quality of life, and disease-specific quality of life were not statistically significant. ConclusionsAdding a tailored eHealth intervention to health education and individual counseling did not affect outcomes among adolescents with congenital heart disease. Our results do not support the use of this eHealth intervention in adolescents with complex congenital heart disease. Trial registrationClinical trials.gov identifier: NCT01189981

Cardiorespiratory fitness in long-term lymphoma survivors after high-dose chemotherapy with autologous stem cell transplantation

Background:Cardiorespiratory fitness as measured by peak oxygen consumption (VO2peak) is a strong predictor of longevity and may be compromised by anticancer therapy, inactivity, and smoking. We compared VO2peak among lymphoma survivors (LSs) with reference data from healthy sedentary subjects, after a 10.2-year (mean) follow-up post high-dose chemotherapy with autologous stem cell transplantation (HDT-ASCT). We further examined the association between VO2peak and treatment, physical activity, smoking, pulmonary, and cardiac function.Methods:Lymphoma survivors treated with HDT-ASCT in Norway 1987–2008 were eligible. VO2peak was assessed by cardiopulmonary exercise testing. Pulmonary function testing and echocardiography were also conducted. Data on treatment, physical activity, and smoking were collected from hospital records and questionnaires. VO2peak was compared with age–sex predicted reference data. Linear regression was used to associate clinical factors with VO2peak cross-sectionally.Results:A total of 194 LSs without heart failure were studied. Mean VO2peak was 4.5% and 7.7% below norms in females and males, respectively. Twenty-two percent had impaired (<80% predicted) VO2peak. Decreasing VO2peak was associated with impaired diffusion capacity and current smoking, while physical activity level and VO2peak were positively associated.Conclusion:We suggest increased attention towards physical activity counseling and smoking cessation advice to preserve cardiorespiratory fitness in LSs after HDT-ASCT. Patients with impaired diffusion capacity may benefit from subsequent monitoring to detect pulmonary vascular diseases.

Prediction of Maximal Oxygen Consumption in Healthy Adult Skaters Using the Auggie-10 Single Stage Skate Test

Maximal oxygen consumption is the most accurate measure for indicating cardiovascular function. A variety of submax assessments have been proven viable alternatives. Both maximal and submax field tests for estimating VO2peak for cycling, walking, or running have been previously developed and validated. PURPOSE: To develop a submax skating test that would be suitable for estimating VO2peak in adult skaters. METHODS: Subjects were recruited during open public skating and agreed to participate. Subjects included 16 males and 24 females ranging in age from 19 to 59 years, who were self-classified as capable skaters (age = 35.5 ± 7.6 yrs, ht. = 66.3± 4.4 in, wt. = 140.7 ± 23.3 lbs). All completed a graded exercise test to fatigue with expired gas analysis (Medgraphics, VO2000). Participants performed on-ice and skated at a self-selected speed, 10 times around the rink in a large figure 8 routine. The center dot was the mid and the nets the ends. Heart rate and skating time was recorded as they finished. For males, mean VO2peak 47.3 + 5.3 ml/kg/min, mean skate time 3.8 + 0.5 minutes, mean heart rate 165.3 + 21.0 b/min. For females, mean VO2peak 41.0 + 5.1 ml/kg/min, mean skate time 4.5 + 1.0 minutes, mean heart rate 167.0 + 16.3 b/min. Regression analysis factors age, weight, height, gender, end heart rate, and skate time was performed in the multiple linear model to predict peak VO2. RESULTS: Skate time was significantly correlated with VO2peak, r = -.41, F(1,38) = 7.9, p=.008. Regression analysis also indicated that heart rate was a significant predictor, F(1,37) = 7.5, p=.009, after skate time was already included in the model. Gender was also a significant predictor, F(1,36) = 6.0, p=.019, after skate time and heart rate were in the model. Neither age F(1,35) = 1.9, p=.177, height F(1,35) = 2.5, p=.120, weight F(1,35) = 3.9, p=.057, accounted for no additional variation. The analysis created a regression equation to predict peak oxygen based on the Auggie-10 skate test: VO2peak (ml/kg/min) = 71.43 - (2.77 x skate time in minutes) - (0.11 x heart rate in b/min) + (4.22 x gender), (1 = male; 0 = female), R-squared = .41, SEE = 4.8 ml/kg/min. CONCLUSION: The derived model provides a useful field test for estimating VO2peak from skating. The accuracy of the derived model is similar to other submax field tests based on cycling, walking, or non-exercise models.

High-intensity Interval Training In Overweight And Sedentary Adults

High-intensity interval training (HIIT) is well-established as a methodology for improving metabolic health and performance parameters. Research also demonstrates that HIIT is generally well-tolerated in a variety of populations. Less established is the impact of HIIT on intentions to exercise. PURPOSE: Investigate intentions toward engagement in HIIT exercise among overweight and insufficiently active adults. METHODS: 48 overweight-to-obese participants (mean BMI = 28, mean VO2 peak = 29 ml/kg/min) completed four counterbalanced trials comprised of a 30-minute continuous trial at 33% peak power (CONT) and three 20-minute interval trials that alternated between 85% and 15% peak power using 1:1 work-to-recovery ratios: 15 secs (INT-15), 30 secs (INT-30), and 60 secs (INT-60). RESULTS: Data was analyzed using RM ANOVA and pairwise comparisons. Intention to engage in each trial regularly in the near future was neutral-to-positive (4.9-6.0 on a 1-9 scale) with greater intention to complete INT-30 trials than CONT (p < 0.05; ES = 0.4) or INT-60 (p < 0.05; ES = 0.4) trials. Additional analyses revealed positive intentions to engage in exercise of any kind in the near future (7.2-7.4 on a 1-9 scale) but no difference between trials (p > 0.10). CONCLUSIONS: Findings indicate that 15-sec and 30-sec HIIT trials produce future intentions to exercise that are equal to or greater than intentions to engage in moderate continuous exercise. These results combined with findings for affective and enjoyment responses to exercise provide justification for the utilization of shorter interval trials as a relatively time-efficient alternative to lower intensity continuous exercise when promotion of intention to exercise is a desired outcome.

Experienced Cyclists Predict The Highest Sustainable Intensity Of Exercise More Effectively Than Critical Power Testing.

Critical Power (CP) demarcates the boundary between sustainable and unsustainable exercise, and it is widely used as a measure of exercise tolerance/performance. Evaluation typically consists of a time-consuming and physically demanding protocol of 3-5 time-to-exhaustion trials (TTE) ranging from 1 to 20 min. However, the power output (PO) associated with the calculated CP does not always reflect a sustainable intensity of exercise, and lactate concentration ([La]) cannot be stabilized (i.e. lactate steady-state is not reached). PURPOSE: To test cyclists’ ability to predict their CP based on their own perception of effort, and to compare this PO with those derived from 5 TTE trials and maximal lactate steady-state (MLSS) measurements. METHODS: Seven experienced cyclists (28±3 yrs; 68.4±7.3 kg; 175±9 cm) participated in the study. A ramp incremental test to exhaustion was performed on a cycle ergometer (Velotron Dynafit Pro, Racer Mate, Seattle, WA, USA) for determination of VO2peak (Quark CPET, Cosmed, Rome, Italy) and peak PO (POpeak). PO of CP from 5 TTE trials was derived from a 2-parameter hyperbolic model (POHYP). Participants also performed two 30-min rides at a self-selected PO (POSELF) that they considered the highest intensity of exercise they could sustain for a prolonged time. Additionally, participants performed 30-min rides at the estimated POHYP for determination of PO at MLSS (POMLSS). [La] was measured at 5-min intervals and POMLSS was considered as the highest PO at which variation of [La] ≤ 1.0 mM·L-1 between the 10th and the 30th min. RESULTS: Mean VO2PEAK and POPEAK were 4.30±0.67 L·min-1 and 383±53 W, respectively. POHYP, POSELF and POMLSS were similar (267±39 W, 246±37 W and 246±37 W, respectively; p > 0.05). Bland-Altman plots were used to determine limits of agreement (LOA) between POSELF and POMLSS (-22 to 22 W, bias = 0; p > 0.05), POHYP and MLSS (-8 to 51 W, bias = 21; p > 0.05) and POSS and POHYP (-39 to -4 W, bias = -21 W; p > 0.05). Although POSELF and POHYP had similar magnitudes of range when compared to POMLSS, POHYP consistently over predicted POSELF and POMLSS. CONCLUSION: Experienced cyclists can predict their maximal sustainable PO for a prolonged time-trial with more precision than the current CP testing. This finding challenges the practical application of this test in experienced cyclists.

Comparison of Two Different Sprint Interval Training Work-to-Rest Ratios on Acute Inflammatory Responses.

BackgroundThe study aims to compare how work-to-rest ratio (W:R) influences insulin sensitivity (Si) and inflammatory responses following one session of sprint interval training (SIT).MethodsThirteen men and two women completed a cross-over comparison of two SIT interventions—Tabata (TAB), 10 × 20-s sprints/10-s rest, and Wingate (WIN), 5 × 30-s sprints with 270-s rest. IL-6, IL-10, and TNF-α were assessed at baseline, immediately following, and 1 h after SIT, as well as prior to the 24-h post-exercise oral glucose tolerance tests (OGTTs).ResultsParticipants were 23.8 (±3.5) years old and 180.0 (±10.2) cm tall, weighed 78.5 (13.0) kg, and had 16.9 (±6.5) % body fat, with a mean VO2Peak of 42.0 (±7.9) ml kg−1 min−1. There were no differences in total work (kJ) between TAB (64.7 ± 12.0) and WIN (68.0 ± 15.0). Mean (±95 % CI) Si 24 h changed −2.8 (−5.1, −0.5) from baseline after TAB and −3.9 (−6.9, −0.9) after WIN. Cytokines were measured in pg ml−1 and expressed as mean change (±95 % CI). IL-6 increased significantly immediately following SIT for TAB 0.70 (0.23, 1.17), and WIN 1.11 (0.60, 1.62), and remained elevated 1 h post SIT for TAB 1.10 (0.37, 1.83), and WIN 0.95 (0.26, 1.65). IL-10 showed a significant positive change immediately following exercise for TAB 1.53 (0.77, 2.29) and WIN 1.59 (0.58, 2.59). TNF-α also increased immediately both TAB 3.26 (1.57, 4.96) and WIN 3.05 (0.56, 5.54) and was directly proportional to IL-10 (r = 0.64, p < 0.0001).ConclusionsW:R did not alter either the inflammatory or metabolic response following SIT nor does SIT improve 24-h Si, despite increased levels of IL-10.

Abstract P4-10-16: Long term effects of trastuzumab on cardiopulmonary and left ventricular function in women with HER2 overexpressing breast cancer

Abstract Background: Adjuvant trastuzumab (TRZ) is the standard of care for HER2-overexpressing (HER2+) early stage breast cancer (EBC) patients (PTS), with five-year survival rates exceeding 90%. However, significant cardiac toxicities are observed, with a fivefold increase in clinical heart failure (HF). Left ventricular (LV) remodeling (increased heart size and mass) is an early indicator of cardiac injury, progressing to further LV dysfunction, reduced exercise tolerance and overt HF. Therefore, effective prevention of such negative sequelae is of enormous clinical interest. As the pivotal TRZ trials assessed cardiac function with MUGA or echocardiography, insensitive modalities to evaluate LV remodeling, the long-term sequelae of TRZ remain unknown. Objective: to determine the long term effects of trastuzumab on cardiopulmonary and left ventricular function in women with HER2 overexpressing breast cancer. Additionally as aerobic training is an effective intervention in HF PTS who adhere to prescribed exercise, a sub-analysis compared those who adhered during a 4 month exercise intervention (AEX) vs those who did not adhere (NEX). Methods: 16 PTS (mean age 58 ± 7) who participated in an exercise intervention study during the first 4 months of TRZ therapy were recruited, with an average of 4 years elapsing since TRZ completion. Cardiopulmonary exercise (VO2peak) testing and resting cardiac MRI (CMR) were performed and compared with baseline and 4 month assessments. Adherence to exercise intevention was defined as attendance ≥80% prescribed sessions. Results: All 16 PTS reported independent living with no limitations to ADLs. At 4 years, mean VO2peak for all PTS was 22.4 ml/kg/min (20.0 at baseline and 22.0 at 4 months). In AEX PTS, higher VO2peak persisted 4 years after cessation of therapy, 4.1 mL/kg/min higher than NEX PTS (24.9 and 20.8 mL/kg/min, respectively ). Mean LVEF for all PTS was 60 ± 6%, not significantly different from baseline or 4 months (61 ± 5 and 55 ± 4%, respectively) . Statistically significant interactions of exercise adherence to other CMR metrics were not observed. Conclusions: Clinically significant impairment of cardiopulmonary function (equal to 14 years of aging) are present before therapy and persist in PTS four years following exposure to TRZ-based chemotherapy. This observation is consistent with our other work, and occurs on a background of normal LVEF, implying additional negative effects to other components of the oxygen cascade. As mortality risk has been shown to decrease by 17% for every 3.5 mL/kg/min difference in aerobic capacity in healthy females, these findings indicate adherence to exercise interventions during TRZ-based therapy has potentially important long-term implications. Citation Format: Pituskin E, Paterson I, Ghosh S, Mackey JR, Haykowsky MJ. Long term effects of trastuzumab on cardiopulmonary and left ventricular function in women with HER2 overexpressing breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-10-16.

Validity and Test-Retest Reliability of the TIVRE-Basket Test for the Determination of Aerobic Power in Elite Male Basketball Players.

The aims of this study were to (a) determine the relationship between performance on the court-based TIVRE-Basket test and peak aerobic power determined from a criterion laboratory-based incremental treadmill test and (b) to examine the test-retest reliability of the TIVRE-Basket test in elite male basketball players. To address aim 1, 36 elite male basketball players (age: 25.2 ± 4.7 years, weight: 94.1 ± 11.4 kg, height: 195.83 ± 9.6 cm) completed a graded treadmill exercise test and the TIVRE-Basket within 72 hours. The mean distance recorded during the TIVRE-Basket test was 4001.8 ± 176.4 m, and mean VO2 peak was 54.7 ± 2.8 ml · kg(-1) · min(-1), and the correlation between the 2 parameters was r = 0.824 (p ≤ 0.001). Linear regression analysis identified TIVRE-Basket distance (in meters) as the only unique predictor of VO2 peak in a single variable plus constant model: VO2 peak = 2.595 + (0.13 × TIVRE-Basket distance [in meters]). Performance on the TIVRE-Basket test accounted for 67.8% of the variance in VO2 peak (t = 8.466, p ≤ 0.001, 95% confidence interval: 0.01-0.016, SEE: 1.61). To address aim 2, 20 male basketball players (age: 26.7 ± 4.2 years, height: 1.94 ± 0.92 cm, weight: 94.0 ± 9.1 kg) performed the TIVRE-Basket test on 2 occasions. There was no significant difference in total distance covered between trial 1 (4138.8 ± 677.3 m) and trial 2 (4188.0 ± 648.8 m; t = 0.5798, p = 0.5688). Mean difference between trials was 49.2 ± 399.5 m, with an intraclass correlation coefficient of 0.85 suggesting a moderate level of reliability. Standardized typical error of measurement was 0.88%, representing a moderate degree of trial-to-trial error, and the Coefficient of Variation (CV) was 6.3%. The TIVRE-Basket test therefore represents a valid and moderately reliable court-based sport-specific test of aerobic power for use with individuals and teams of elite-level male basketball players. Future research is required to ascertain its validity and reliability in other basketball populations, for example, across age groups, at different levels of competition, in females and in different forms of the game, for example, wheelchair basketball.

Cardiovascular risk and fitness in veteran football players

ABSTRACTVeteran football players above 40 years have rarely been subject to scientific investigations. This is worrisome because their number is considerable and their cardiovascular risk probably increased. Therefore, a cross-sectional study was conducted in 100 football players between 40 and 63 years of age. This included a medical history and physical examination, venous blood sampling, measurement of resting blood pressure, a resting electrocardiogram (ECG), an exhaustive cycle ergometry and a multistage field test. Also, measurements of heart rate and blood lactate concentration were carried out during one typical training session and one match. Participants trained 1.0 ± 0.6 sessions per week and played 27 ± 8 matches per season. Of them, 19% were smokers. Resting blood pressure was 138 ± 15/88 ± 8 mmHg. Hypertension prevalence (WHO definition) was 66%. Total cholesterol averaged 220 ± 41 mg . dl−1, HDL 46 ± 13 mg . dl−1 and LDL 134 ± 33 mg . dl−1. The average 10-year risk for cardiovascular events (Framingham score) was 6%. Mean maximal power output on the cycle ergometer was 2.8 ± 0.6 W . kg−1, mean VO2peak 40.0 ± 7.3 ml . min−1 . kg−1. Comparing training and competition, no significant differences in cardiovascular and metabolic load were found. In summary, their cardiovascular risk was similar to age-adjusted reference values. However, they showed slightly better ergometric performance. More frequent training stimuli might be necessary to reach more favourable risk factor profiles. Training and competition lead to similar cardiocirculatory and metabolic stress which is considerably high and might put players into danger who have pre-existing cardiac disease.

Peak oxygen uptake and self-reported physical health are strong predictors of long-term survival after heart transplantation.

Peak oxygen uptake (VO2peak ) is known as the gold standard measure of cardiopulmonary fitness. We therefore hypothesized that measures of physical health would predict long-term survival in heart transplant recipients (HTx). This retrospective study investigated survival in two HTx populations; the cardiopulmonary exercise test (CPET) cohort comprised 178 HTx patients who completed a VO2peak test during their annual follow-up (1990-2003), and the SF-36 cohort comprised 133 patients who completed a quality of life questionnaire, SF-36v1 (1998-2000). Mean (SD) age in the CPET cohort was 52 (12) yr and 54 (11) yr in the SF-36 cohort. Mean observation time was, respectively, 11 and 10 yr. Mean (SD) VO2peak was 19.6 (5.3) mL/kg/min, and median (IR) physical function (PF) score was 90 (30). VO2peak and PF scores were both significant predictors in univariate Cox regression. Multiple Cox regression analyses adjusted for other potential predictors showed that VO2peak , age, and cardiac allograft vasculopathy (CAV) were the most important predictors in the CPET cohort, whereas age, PF score, smoking, and CAV were the most important predictors in the SF-36 cohort. In Kaplan-Meier analysis, VO2peak and PF scores above the median value were related to significant longer survival time. Peak oxygen uptake and self-reported physical health are strong predictors for long-term survival in HTx recipients. VO2peak is a crucial measurement and should be more frequently used after HTx.