Preserved Left Atrial Mechanics Following a 5-h Laboratory Triathlon in Euhydrated Athletes.

The purpose of this study was to investigate echocardiographic changes in left ventricular (LV) diastolic filling and left atrial (LA) strain mechanics following prolonged exercise. Ten male triathletes completed a 60-min swim, 180-min bike exercise, and a 60-min all-out run in a laboratory environment. Special attention was paid to prevent dehydration and energy deficit during the exercise protocol. All participants underwent comprehensive echocardiographic analyses of Doppler- and volumetric-derived LV diastolic filling indices and novel speckle-tracking echocardiography (STE)-derived LA strain indices. LV stroke volume (pre: 108.0±15.9 vs. post: 88.8±19.0 mL; p=0.03) and LA passive emptying volume (pre: 31.2±7.5 vs. post: 22.4±9.8 mL; p=0.05) were significantly reduced following the exercise protocol. Of the STE-derived indices of LA function, reservoir and conduit strain did not change significantly, while there was a trend towards enhanced contraction strain (pre: 15.1±3.8 vs. post: 19.4±4.8%; p=0.07). Resting heart rate was significantly higher post-exercise (53.1±5.0 vs. 81.9±16.9 bpm; p<0.001) and its change correlated strongly with depression of Doppler-derived ratio of early to late ventricular filling velocities (r=0.74, p=0.01) and reduction of LA passive emptying volume (r=0.86, p=0.01). Following prolonged exercise, LV stroke volume was reduced due to heart rate related reduction in LA passive emptying volume whereas global LA strain mechanics were not compromised in this study.

Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon.

The ingestion of exogenous carbohydrates (CHO) during prolonged endurance exercise, such as long-distance triathlon, is considered beneficial with regard to performance. However, little is known about whether this performance benefit differs among different forms of CHO administration. To this end, the purpose of our study was to determine the impact of CHO ingestion from a semisolid source (GEL) on measures of performance and gastrointestinal (GI) comfort compared with CHO ingestion from a liquid source (LIQ). Nine well-trained triathletes participated in this randomized crossover study. Each participant completed a 60-min swim, 180-min bike exercise, and a 60-min all-out run in a laboratory environment under 2 conditions, once while receiving 67.2 ± 7.2 g · h-1 (M ± SD) of CHO from GEL and once while receiving 67.8 ± 4.2 g · h-1 of CHO from LIQ. The amount of fluid provided was matched among conditions. Respiratory exchange ratio (RER), blood glucose, and lactate as well as GI discomfort were assessed at regular intervals during the experiment. The distance covered during the final all-out run was not significantly different among participants ingesting GEL (11.81 ± 1.38 km) and LIQ (11.91 ± 1.53 km; p = .89). RER, blood glucose, and lactate did not differ significantly at any time during the experiment. Seven participants reported GI discomfort with GEL, and no athlete reported GI discomfort with LIQ (p = .016). This study suggests that administration of GEL does not alter long-distance triathlon performance when compared with LIQ, but GEL seems to be associated with reduced GI tolerance. Athletes should consider this a potential disadvantage of GEL administration during long-distance triathlon.

Long COVID: Distinction between Organ Damage and Deconditioning.

(1) Background: Long COVID syndrome refers to long-term sequelae of the novel viral disease, which occur even in patients with initially mild disease courses. However, there is still little evidence of the actual organic consequences and their frequency, and there is no standardized workup to diagnose long COVID syndrome yet. In this study, we aim to determine the efficiency of a stepwise diagnostic approach for reconvalescent COVID-19 patients with cardiopulmonary symptoms. (2) Methods: The diagnostic workup for long COVID syndrome included three steps. In the first step, the focus was on broad applicability (e.g., blood tests and body plethysmography). In the second step, cardiopulmonary exercise testing (CPET) and cardiac MRI (CMR) were used. The third step was tailored to the individual needs of each patient. The observation period lasted from 22 February to 14 May 2021. (3) Results: We examined 231 patients in our long COVID unit (mean [SD] age, 47.8 [14.9], 132 [57.1%] women). Acute illness occurred a mean (SD) of 121 (77) days previously. Suspicious findings in the first visit were seen in 80 (34.6%) patients, prompting further diagnostics. Thirty-six patients were further examined with CPET and CMR. Of those, 16 (44.4%) had pathological findings. The rest had functional complaints without organ damage ("functional long COVID"). Cardiopulmonary sequelae were found in asymptomatic as well as severe courses of the initial COVID-19 disease. (4) Conclusions: A structured diagnostic pathway for the diagnosis of long COVID syndrome is practicable and rational in terms of resource allocation. With this approach, manifest organ damage can be accurately and comprehensively diagnosed and distinguished from functional complaints.