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In a 77-year-old former world-record-holding male marathoner (2:08:33.6), this study sought to investigate the impact of lifelong intensive endurance exercise on cardiac structure, function, and the trajectory of functional capacity (determined by maximal oxygen consumption, V̇ o 2max) throughout the adult lifespan. As a competitive runner, our athlete (DC) reported performing up to 150–300 miles/wk of moderate-to-vigorous exercise and sustained 10–15 h/wk of endurance exercise after retirement from competition. DC underwent maximal cardiopulmonary exercise testing in 1970 (aged 27 yr), 1991 (aged 49 yr), and 2020 (aged 77 yr) to determine V̇ o 2max. At his evaluation in 2020, DC also underwent comprehensive cardiac assessments including resting echocardiography, and resting and exercise cardiac magnetic resonance to quantify cardiac structure and function at rest and during peak supine exercise. DC's V̇ o 2max showed minimal change from 27 yr (69.7 mL/kg/min) to 49 yr (68.1 mL/kg/min), although it eventually declined by 36% by the age of 77 yr (43.6 mL/kg/min). DC's V̇ o 2max at 77 yr, was equivalent to the 50th percentile for healthy 20- to 29-yr-old males and 2.4 times the requirement for maintaining functional independence. This was partly due to marked ventricular dilatation (left-ventricular end-diastolic volume: 273 mL), which facilitates a large peak supine exercise stroke volume (200 mL) and cardiac output (22.2 L/min). However, at the age of 78 yr, DC developed palpitations and fatigue and was found to be in atrial fibrillation requiring ablation procedures to revert his heart to sinus rhythm. Overall, this life study of a world champion marathon runner exemplifies the substantial benefits and potential side effects of many decades of intense endurance exercise. NEW & NOTEWORTHY: This life study of a 77-yr-old former world champion marathon runner exemplifies the impact of lifelong high-volume endurance exercise on functional capacity (V̇ o 2max equivalent to a 20- to 29-yr-old), partly due to extreme ventricular remodeling that facilitates a large cardiac output during exercise despite reduced maximal heart rate. Although it is possible that this extreme remodeling may contribute to developing atrial fibrillation, the net benefits of extreme exercise throughout this athlete's lifespan favor increased health span and expected longevity. [ABSTRACT FROM AUTHOR]

Aims Heart failure (HF) has a major impact on exercise tolerance that may (in part) be due to abnormalities in body and skeletal muscle composition. This systematic review and meta-analysis aims to assess how differences in whole-body and skeletal muscle composition between patients with HF and non-HF controls (CON) contribute to reduced peak oxygen uptake (VO2peak). Methods and results The PubMed database was searched from 1975 to May 2024 for eligible studies. Cross-sectional studies with measures of VO2peak, body composition, or muscle biopsies in HF and CON were considered. Out of 709 articles, 27 studies were included in this analysis. Compared with CON, VO2peak [weighted mean difference (WMD): −9.96 mL/kg/min, 95% confidence interval (CI): −11.71 to −8.21), total body lean mass (WMD: −1.63 kg, 95% CI: −3.05 to −0.21), leg lean mass (WMD: −1.38 kg, 95% CI: −2.18 to −0.59), thigh skeletal muscle area (WMD: −10.88 cm2 , 95% CI: −21.40 to −0.37), Type I fibres (WMD: −7.76%, 95% CI: −14.81 to −0.71), and capillary-to-fibre ratio (WMD: −0.27, 95% CI: −0.50 to −0.03) were significantly lower in HF. Total body fat mass (WMD: 3.34 kg, 95% CI: 0.35–6.34), leg fat mass (WMD: 1.37 kg, 95% CI: 0.37–2.37), and Type IIx fibres (WMD: 7.72%, 95% CI: 1.52–13.91) were significantly higher in HF compared with CON. Absolute VO2peak was significantly associated with total body and leg lean mass, thigh skeletal muscle area, and capillary-to-fibre ratio. Conclusion Individuals with HF display abnormalities in body and skeletal muscle composition including reduced lean mass, oxidative Type I fibres, and capillary-to-fibre ratio that negatively impact VO2peak. [ABSTRACT FROM AUTHOR]

Background: Breast cancer (BC) survivors treated with anthracycline-based chemotherapy (AC) have increased risk of functional limitation and cardiac dysfunction. We conducted a 12-month randomized controlled trial in 104 early-stage BC patients scheduled for AC to determine if 12-months of exercise training (ExT) could attenuate functional disability (primary endpoint), improve cardiorespiratory fitness (VO2peak) and prevent cardiac dysfunction. Methods: Women aged 40-75 years with stage I-III BC scheduled for AC were randomized to 3-4 days/wk of aerobic and resistance ExT for 12-months (n = 52) or usual care ([ UC ], n = 52). Functional measures were performed at baseline, 4-weeks following AC (4-months) and at 12-months comprising: 1) cardiopulmonary exercise testing to quantify VO2peak and functional disability (VO2peak ≤18.0mL/kg/min), 2) cardiac reserve (response from rest to peak exercise) quantified using exercise cardiac magnetic resonance measures to determine changes in left- and right-ventricular ejection fraction [ LVEF, RVEF ], cardiac output [ CO ], and stroke volume [ SV ]), 3) standard-of-care echocardiography-derived resting LVEF and global longitudinal strain [ GLS ], and 4) biochemistry (troponin and B-type natriuretic peptide [ BNP ]). Results: Among 104 participants randomized, greater study attrition was observed among UC participants (P=0.031) with 93 women assessed at 4-months (ExT: n=49, UC: n=44) and 87 at 12-months (ExT: n=49, UC: n=38). ExT attenuated functional disability at 4-months (OR: 0.32 [95% CI 0.11, 0.94], P=0.03), but not at 12-months (OR: 0.27, [95% CI 0.06, 1.12], P=0.07). In a per-protocol analysis, functional disability was entirely prevented at 12-months among participants adherent to ExT (ExT: 0% vs. UC: 20%, P=0.005). As compared with UC at 12-months, ExT was associated with a net +3.5 mL/kg/min improvement in VO2peak that coincided with greater CO, SV, LVEF and RVEF reserve (P<0.001 for all). There was no effect of ExT on resting measures of LV function. Post-chemotherapy troponin increased less in ExT than UC (8-fold vs. 16-fold increase, P=0.002). There were no changes in BNP in either group. Conclusions: In women with early-stage BC undergoing AC, 12-months of ExT did not attenuate functional disability but provided large and clinically meaningful benefits on VO2peak and cardiac reserve. Clinical Trial Registration: URL: https://www.anzctr.org.au/ Unique Identifier: ACTRN12617001408370. [ABSTRACT FROM AUTHOR]

Background: MRI offers quantification of proton density fat fraction (PDFF) and tissue characteristics with T1 mapping. The influence of age, sex, and the potential confounding effects of fat on T1 values in skeletal muscle in healthy adults are insufficiently known., Purpose: To determine the accuracy and repeatability of a saturation-recovery chemical-shift encoded multiparametric approach (SR-CSE) for quantification of T1 Water and muscle fat content, and establish normative values (age, sex) from a healthy cohort., Study Type: Prospective observational; phantoms (NiCL 2 -agarose T1 phantoms with no fat content; gadolinium T1 phantoms with mixed fat-water content)., Populations: A total of 130 healthy community-dwelling adults (63 male, 18-76 years) free of chronic health conditions that require regular prescription medication, and with no contraindications to MRI., Field Strength/sequence: 2.89 T; gradient echo sequences including saturation-recovery chemical-shift encoded T1 mapping (SR-CSE); MOLLI; SASHA; CSE; and single voxel spectroscopy., Assessment: SR-CSE provided T1 Water and PDFF maps for assessment of intramuscular (MF Intra ), intermuscular (MF Inter ), and subcutaneous fat and muscle volumes (thigh, paraspinal muscles). Comparison with MOLLI/SASHA T1 mapping., Statistical Tests: Univariable and multivariable linear regression, general linear models, Bland and Altman, coefficient of variation (CV). P-value <0.05 was considered statistically significant., Results: Phantom and in vivo validation studies showed excellent accuracy of SR-CSE T1 Water and PDFF vs. values from reference standards and repeatability CVs between 0.2% and 2.6% for T1 Water , R2*, MF Inter , MF Intra , subcutaneous fat and muscle volumes. Mean T1 Water was 36 msec significantly higher in females (1445 ± 23 msec vs. 1409 ± 22 msec), with no age-effect (P = 0.35). Females had significantly higher values for MF Inter (10.4% ± 4.8% vs. 7.1% ± 2.9%) and MF Intra (2.6% ± 1.0% vs. 2.3% ± 0.8%), both of which increased with age, secondary to lower muscle volume. MOLLI and SASHA T1 values had a fat-related bias of 21.7/35.0 msec per 1% increase in fat fraction (MFF Intra ), in vivo, and a constant bias of -319.8/+35.6 msec, respectively., Data Conclusion: SR-CSE provides accurate (vs. phantoms) and repeatable assessment of water-specific T1 values and muscle and fat volumes. Conventional methods (SASHA, MOLLI) have a significant fat-modulated T1-bias. T1 Water values are higher in females with no significant age dependence., Plain Language Summary: We developed and tested the accuracy of a new MRI approach to measure tissue damage in skeletal muscle using a method called T1 mapping. The approach also provided matching images of fat within the muscle. We measured T1 values and muscle fat volumes in the thighs of 130 healthy adults to define normal values in healthy people and to understand if these values are influenced by age, sex, or weight. We found that our MRI technique accurately measured T1 values and fat volumes within muscle and we defined normal ranges of values, which were different in healthy males and females., Level of Evidence: 2 TECHNICAL EFFICACY: Stage 1., (© 2025 The Author(s). Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Aims: Cardiovascular disease (CVD) is a leading cause of mortality in childhood cancer survivors (CCS) that may be related to the cardiotoxic effects of radiation or chemotherapy and concomitant reductions in cardiorespiratory fitness. Therefore, we sought to compare cardiorespiratory fitness (peak oxygen uptake, V̇O2peak) between CCS and age-matched non-cancer controls (CON). Secondary outcomes included hemodynamics and resting cardiac function., Methods: Embase, Scopus, MEDLINE, CINAHL and SPORTDiscus databases were searched from inception to June 2023 for eligible studies. Cross-sectional studies with V̇O2peak measured in CCS and CON were included. Differences in outcomes and pooled estimates for each outcome were estimated from a fixed effects meta-analysis and between group differences were reported as a weighted mean difference (WMD)., Results: Of 2026 studies identified, 18 reported V̇O2peak (CCS: n=786, 44% female, mean age: 16-years, time post-therapy: 5.8 years; CON: n=1379, 50% female, mean age: 16-years). V̇O2peak was lower in CCS (WMD: -7.08mL/kg/min, 95% CI: -7.75 to -6.42, I2: 79%, n=2,165) with no difference for peak exercise heart rate (WMD: -1.4bpm, 95% CI: -3.0 to 0.2, I2: 63%, n=741). Resting left-ventricular ejection fraction (WMD: -1.61%, 95% CI: -2.60 to -0.62, I2.: 49%, n=222) and systolic blood pressure were lower (WMD: -3.8mmHg, 95% CI: -5.7 to -1.9, I2: 25%, n=184) while resting heart rate was higher in CCS (WMD: 4.9bpm; 95% CI: 1.8 to 7.9, I2: 55%, n=262)., Conclusions: CCS have a marked reduction in cardiorespiratory fitness (7.1ml/kg/min lower than CON) that may have important prognostic implications for their future risk of CVD and mortality., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Purpose: Improvements in diagnosis and treatment mean that the long-term health of breast cancer survivors (BCS) is increasingly dictated by cardiovascular comorbidities. This is partly a consequence of exposure to cardiotoxic therapies, which result in cardiac dysfunction and decreased cardiorespiratory fitness (CRF). Exercise training (ExT) is a key therapeutic strategy for secondary prevention and increasing CRF in adults with established cardiovascular disease. Exercise-based cardio-oncology rehabilitation (CORE) has been proposed as an emerging strategy to address CRF and cardiac impairment in BCS. This review aims to (1) provide an overview of the impact of breast cancer therapy on CRF; (2) provide an up-to-date summary of the effects of ExT on CRF and cardiac function in BCS undergoing cardiotoxic therapy; and (3) discuss how traditional ExT approaches can be adapted for BCS undergoing therapy., Review Methods: A literature review was performed based on an intensive literature search for systematic reviews and meta-analyses, randomized and non-randomized controlled trials and single-arm trials investigating the impact of exercise training or cardiac rehabilitation on CRF and/or cardiac function in BCS who are undergoing or have completed cardiotoxic cancer therapy., Summary: Overall, current evidence suggests that ExT induces clinically meaningful benefits for CRF in BCS during and after therapy. There is also emerging evidence that ExT can improve peak exercise measures of cardiac function; however, there is a need for further research to understand how to adapt these effective ExT approaches into clinical CORE-based settings., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)