Focal Myocarditis after Mild COVID-19 Infection in Athletes

COVID-19 infection in athletes usually has a milder course, but in the case of complications, myocarditis and even sudden cardiac death may occur. We examined an athlete who felt symptoms upon returning to training after asymptomatic COVID-19 infection. Physical, laboratory, and echocardiography findings were normal. The cardiopulmonary exercise test was interrupted at submaximal effort due to severe dyspnea in the presence of reduced functional capacity in comparison to previous tests. Cardiac magnetic resonance (CMR) detected the focal myocarditis. After three months of recovery, CMR still revealed the presence of focal myocarditis and the persistence of decreased functional capacity. This case raises the question of screening athletes even after asymptomatic forms of COVID-19 infection.

Detection of effort maximality in adults performing isokinetic wrist flexion and extension

BACKGROUND: The difference between isokinetic eccentric to concentric strength ratios at high and low velocities (DEC) is a powerful tool for identifying submaximal effort in other muscle groups but its efficiency in terms of the wrist extensors (WE) and flexors (WF) isokinetic effort has hitherto not been studied. OBJECTIVE: The objective of the present study is to examine the usefulness of the DEC for identifying suboptimal wrist extensor and flexor isokinetic efforts. METHODS: Twenty healthy male volunteers aged 20–40 years (28.5 ± 3.2) were recruited. Participants were instructed to exert maximal and feigned efforts, using a range of motion of 20∘ in concentric (C) and eccentric (E) WE and WF modes at two velocities: 10 and 40∘/s. E/C ratios (E/CR) where then calculated and finally DEC by subtracting low velocity E/CR from high velocity ones. RESULTS: Feigned maximal effort DEC values were significantly higher than their maximal effort counterparts, both for WF and WE. For both actions, a DEC cutoff level to detect submaximal effort could be defined. The sensitivity of the DEC was 71.43% and 62.5% for WE ad WF respectively. The specificity was 100% in both cases. CONCLUSION: The DEC may be a valuable parameter for detecting feigned maximal WF and WE isokinetic effort in healthy adults.

Pomegranate Extract Improves Maximal Performance of Trained Cyclists after an Exhausting Endurance Trial: A Randomised Controlled Trial

The efficacy of pomegranate (Punica granatum) extract (PE) for improving performance and post-exercise recovery in an active population was equivocal in previous studies. In this study, a randomised, double-blinded, placebo-controlled, balanced, cross-over trial with two arms was conducted. Eligibility criteria for participants were as follows: male, amateur cyclist, with a training routine of 2 to 4 sessions per week (at least one hour per session). The cyclists (n = 26) were divided into treatment (PE) and placebo (PLA) groups for a period of 15 days. After physical tests, the groups were exchanged after a 14-day washout period. Exercise tests consisted of endurance bouts (square-wave endurance exercise test followed by an incremental exercise test to exhaustion) and an eccentric exercise drill. The objective was to assess the efficacy of PE in performance outcomes and post-exercise muscular recovery and force restoration after a prolonged submaximal effort. Twenty-six participants were included for statistical analysis. There was a statistically significant difference in total time to exhaustion (TTE)(17.66–170.94 s, p < 0.02) and the time to reach ventilatory threshold 2 (VT2)(26.98–82.55 s, p < 0.001), with greater values for the PE compared to the PLA group. No significant results were obtained for force restoration in the isokinetic unilateral low limb test. PE, after a prolonged submaximal effort, may be effective in improving performance outcomes at maximal effort and might help to restore force in the damaged muscles.

Stress Testing Protocols

The chapter Exercise Testing Protocols compares the types of protocols available. Historically, exercise testing began with protocols eliciting a submaximal effort. With time, other protocols were developed including intermittent exercise with rest between exercise stages, a ramp protocol with gradually increasing stages, bicycle ergometry, isometric testing and mental stress testing. Given their ability to measure or estimate maximal oxygen consumption (V̇02max) and assess myocardial ischemia during and a peak exercise, maximal treadmill exercise protocols became the most popular. Most commonly used have been those of Bruce, Ellestad, Balke and Ware, Astrand, and Cornell. All successfully achieve maximal workload in a predictable manner.

Effects of pedal rate and power output on cycling kinematics

The aim of this study was to examine the effect of changes in pedal rate and power output in the cycling kinematics of endurance cyclists. Nine male competitive cyclists performed 16 submaximal effort trials of 4 minutes’ duration on a cycle ergometer. Power output was imposed at 50, 100, 150, and 200 W successively for each pedal rate studied (45, 70, 95, 120 rev · min−1). The ankle, knee and hip flexion/extension, and pedal angle (pedal axis/malleolus medialis compared to the horizontal) were analysed. We observed an increase of mean pedal angle and a decrease of magnitude in pedal mobilisation when pedal rate increased or power output decreased. The mean pedal angle recorded during a crank cycle seems to depend on pedal load (power/pedal rate ratio). The supposed effect of pedal rate, power and pedal load on pedal angle was confirmed by adjusting a sin function (with pedal rate, power and power/pedal rate ratio as variables) representing the evolution of pedal angle during the crank evolution to experimental data. The modifications due to power and pedal rate change that were observed in pedal kinematics were generally transferred to the upper joints of the legs.