This study will evaluate cardiorespiratory and peripheral muscle function and their relationship with subjective dyspnea threshold after the surgical correction of congenital heart disease in children. Thirteen children with surgically repaired congenital heart disease were recruited. Each participant performed an incremental exercise test on a cycle ergometer until exhaustion. Gas exchanges were continuously sampled to measure the maximal aerobic parameters and ventilatory thresholds. The functional capacity of the subjects was assessed with a 6 min walk test. At the end of the exercise test, isokinetic Cybex Norm was used to evaluate the strength and endurance of the knee extensor muscle in the leg. Dyspnea was subjectively scored with a visual analog scale during the last 15 s of each exercise step. Oxygen consumption measured at the dyspnea score/VO₂ relationship located at the dyspnea threshold, at which dyspnea suddenly increased. Results: The maximal and submaximal values of the parameters describing the exercise and the peripheral muscular performances were: VO₂ Peak: 33.8 ± 8.9 mL·min⁻¹·kg⁻¹; HR: 174 ± 9 b·min⁻¹; VEmax: 65.68 ± 15.9 L·min⁻¹; P max: 117 ± 27 W; maximal voluntary isometric force MVIF: 120.8 ± 41.9 N/m; and time to exhaustion Tlim: 53 ± 21 s. Oxygen consumption measured at the dyspnea threshold was related to VO₂ Peak (R² = 0.74; p < 0.01), Tlim (R² = 0.78; p < 0.01), and the distance achieved during the 6MWT (R² = 0.57; p < 0.05). Compared to the theoretical maximal values for the power output, VO₂, and HR, the surgical correction did not repair the exercise performance. After the surgical correction of congenital heart disease, exercise performance was impeded by alterations of the cardiorespiratory function and peripheral local factors. A subjective evaluation of the dyspnea threshold is a reliable criterion that allows the prediction of exercise capacity in subjects suffering from congenital heart disease.

This study investigated the long-term cardiovascular effects of coronavirus disease (COVID-19) in elite male athletes by comparing the heart rate variability (HRV), arterial stiffness, and other cardiovascular parameters between those with and without prior COVID-19 infection. Methods: This cross-sectional study evaluated 120 elite male athletes (60 post COVID-19, 60 controls) using anthropometric measurements, body composition analysis, pulmonary function tests, HRV analysis, arterial stiffness assessments, hemodynamic monitoring, and microcirculatory function tests. Results: Athletes post COVID-19 showed significantly higher lean mass (p = 0.007), forced vital capacity (p = 0.001), and forced expiratory volume in 1 s (p = 0.007) than controls. HRV parameters did not significantly differ between the groups. Post-COVID-19 athletes exhibited peripheral vascular resistance (p = 0.048) and reflection index (p = 0.038). No significant differences were observed in the blood pressure, cardiac output, oxygen saturation, or microcirculatory oxygen absorption. Conclusions: Elite male athletes showed notable cardiovascular resilience after COVID-19, with only minor differences in vascular function. The maintained cardiac autonomic function and improved lung parameters in post-COVID-19 athletes suggests an adaptive response. These findings support the cardiovascular health of elite athletes following COVID-19 but emphasize the importance of continued monitoring.

This review assesses the influence of ADRB2 (beta-2 adrenergic receptor) gene polymorphisms on athletic performance and physiological function in humans. The literature was analysed for associations with results in cyclic endurance and speed-strength sports and for effects on the cardiovascular, respiratory and metabolic systems. The GG genotype of ADRB2 is associated with the body mass index of female rhythmic gymnasts and is positively related to successful performance in competition. The Arg16Gly variant influences the cardiovascular and respiratory systems and the expression of endurance in athletes. ADRB2 (rs1042713) has been linked to insulin resistance and to increased fat content in the central part of the body in non-athletes; carriers of the Gln/Gln genotype have less body fat than those with the Gln/Glu and Glu/Glu genotypes (rs1042714) (p = 0.050 and p = 0.009, respectively). The polymorphisms rs1042718 and rs1042719 are associated with longevity in men (A-C haplotype: OR = 1.49, p = 0.0007), and the GG genotype of rs1042714 increases the risk of myocardial infarction 3.3-fold (p = 0.021), indicating an indirect link between ADRB2 and life expectancy mediated by cardiovascular disease. The Arg16Gly and Gln27Glu polymorphisms are also associated with an increased risk of respiratory pathology. The data obtained across studies are highly contradictory, which may be due to differences in the populations studied, study design, ethnicity, measurement scales, nutrition and sample size. At present, the ADRB2 gene may be considered a candidate marker for talent identification in sport and for the assessment of the risk of certain diseases and injuries, although the available evidence remains inconsistent.