Overtraining syndrome (OTS) is a significant medical condition observed predominantly in endurance athletes and characterised by a decline in performance and disruptions in multiple physiological functions. Given the increasing popularity of endurance training and the complex nature of OTS diagnosis, there is a compelling need for comprehensive case studies. The case series summarises one professional runner, one competitive runner and one recreational runner who were diagnosed with OTS. Key parameters observed include symptoms, diagnostic journey, recovery initiatives and return-to-sport outcomes. All three athletes showed typical OTS manifestations, including impaired performance and multisystem dysfunction (ie, endocrine, nervous, immune and gastrointestinal systems). Following a mandated cessation from training, active recovery strategies were instituted. Two of the three athletes successfully returned to competition. Specific recovery patterns and potential relapse indicators were also identified. The comprehensive examination of the cases underscores the complex nature of OTS diagnosis, its multifaceted symptoms and the critical importance of structured recovery. The case series elucidates the importance of heightened awareness and early intervention to diagnose and manage OTS. In addition, we propose an anecdotal Return to Running Protocol individualised to the athlete's response.

Background: Athletes can experience exercise-induced transient arrythmias during high-intensity exercise or competition, which are difficult to capture on traditional Holter monitors or replicate in clinical exercise testing. The aim of this study was to investigate the reliability of a portable single channel ECG sensor and data recorder (PluxECG) and to evaluate the confidence and reliability in interpretation of ECGs recorded using the PluxECG during remote rowing. Methods: This was a two-phase study on rowing athletes. Phase I assessed the accuracy and precision of heart rate (HR) using the PluxECG system compared to a reference 12-lead ECG system. Phase II evaluated the confidence and reliability in interpretation of ECGs during ergometer (ERG) and on-water (OW) rowing at moderate and high intensities. ECGs were reviewed by two expert readers for HR, rhythm, artifact and confidence in interpretation. Results: Findings from Phase I found that 91.9% of samples were within the 95% confidence interval for the instantaneous value of the changing exercising HR. The mean correlation coefficient across participants and tests was 0.9886 (σ = 0.0002, SD = 0.017) and between the two systems at elevated HR was 0.9676 (σ = 0.002, SD = 0.05). Findings from Phase II found significant differences for the presence of artifacts and confidence in interpretation in ECGs between readers’ for both intensities and testing conditions. Interpretation of ECGs for OW rowing had a lower level of reader agreement than ERG rowing for HR, rhythm, and artifact. Using consensus data between readers’ significant differences were apparent between OW and ERG rowing at high-intensity rowing for HR (p = 0.05) and artifact (p = 0.01). ECGs were deemed of moderate-low quality based on confidence in interpretation and the presence of artifacts. Conclusions: The PluxECG device records accurate and reliable HR but not ECG data during exercise in rowers. The quality of ECG tracing derived from the PluxECG device is moderate-low, therefore the confidence in ECG interpretation using the PluxECG device when recorded on open water is inadequate at this time.

Background/Objectives: The peak oxygen consumption (VO2) during cardiopulmonary exercise testing (CPET) is a strong predictor of all-cause mortality. The cardiac output, a key determinant of VO2, can be assessed using resting echocardiographic parameters. The heart rate recovery and ventilatory efficiency (VE/VCO2 slope) from CPET offer additional insights into cardiovascular fitness. Methods: This study aimed to identify resting echocardiographic parameters that predict the percentage of predicted peak VO2, heart rate recovery, and VE/VCO2 slope in a general cardiology population. This retrospective analysis included 1909 patients who underwent echocardiography within 3 months of CPET from 2017 to 2022. Patients with potentially confounding co-morbid conditions were removed. Spearman correlations were used to compare 19 echocardiographic parameters to peak VO2, heart rate recovery, and the VE/VCO2 slope, followed by multiple linear regression of peak VO2. Results: Eleven echocardiographic parameters correlated with peak VO2, with the strongest correlations seen with the left ventricular stroke volume index (R = 0.284, p < 0.001), mitral valve medial annular a’ wave velocity (R = 0.142, p < 0.0001), and mitral E-to-e’ ratio (R = −0.117, p < 0.0001). The left ventricular diastolic parameters and mitral E/A ratio correlated strongly with the heart rate recovery and VE/VCO2 slope. The multiple linear regression analysis identified the left ventricular mass index, stroke volume index, mitral valve E wave velocity, tricuspid valve regurgitation peak systolic velocity, tricuspid lateral annular systolic velocity S’, and left atrial volume index as independent predictors of peak VO2 (R² = 0.191). Conclusions: The left ventricular stroke volume, diastolic function, and RV systolic function markers are significant predictors of cardiopulmonary fitness, aiding clinical decision-making in patients without CPET data.

Coarctation of the aorta (CoA) is a relatively rare congenital narrowing of the distal aortic arch to proximal descending thoracic aorta, usually diagnosed in infancy or early childhood with upper extremity hypertension as a typical finding. Late detection in asymptomatic, physically active older adults is rare and can be clinically significant. We present the case of a 65-year-old lifelong endurance athlete found to have transient severe left ventricular (LV) systolic dysfunction after completing a marathon. Stress testing revealed a hypertensive response, prompting cardiac MRI, which detected a new severe juxta-ductal CoA with collateralization. The patient underwent successful endovascular stenting with improved blood pressure response and stabilization of LV function. This case underscores the importance of thorough cardiovascular assessment in older athletes and highlights the impact of lifelong exercise in compensating for congenital defects like CoA.