Eccentric Training in Pulmonary Rehabilitation of Post-COVID-19 Patients: An Alternative for Improving the Functional Capacity, Inflammation, and Oxidative Stress

Abstract

The purpose of this narrative review is to highlight the oxidative stress induced in COVID-19 patients (SARS-CoV-2 infection), describe longstanding functional impairments, and provide the pathophysiologic rationale that supports aerobic eccentric (ECC) exercise as a novel alternative to conventional concentric (CONC) exercise for post-COVID-19 patients. Patients who recovered from moderate-to-severe COVID-19 respiratory distress demonstrate long–term functional impairment. During the acute phase, SARS-CoV-2 induces the generation of reactive oxygen species that can be amplified to a “cytokine storm”. The resultant inflammatory and oxidative stress process causes organ damage, particularly in the respiratory system, with the lungs as the tissues most susceptible to injury. The acute illness often requires a long-term hospital stay and consequent sarcopenia. Upon discharge, muscle weakness compounded by limited lung and cardiac function is often accompanied by dyspnea, myalgia, anxiety, depression, and sleep disturbance. Consequently, these patients could benefit from pulmonary rehabilitation (PR), with exercise as a critical intervention (including sessions of strength and endurance or aerobic exercises). Unfortunately, conventional CONC exercises induce significant cardiopulmonary stress and increase inflammatory and oxidative stress (OS) when performed at moderate/high intensity, which can exacerbate debilitating dyspnoea and muscle fatigue post-COVID-19. Eccentric training (ECC) is a well–tolerated alternative that improves muscle mass while mitigating cardiopulmonary stress in patients with COPD and other chronic diseases. Similar benefits could be realized in post-COVID-19 patients. Consequently, these patients could benefit from PR with exercise as a critical intervention.

A Review Article on Exercise Intolerance in Long COVID: Unmasking the Causes and Optimizing Treatment Strategies

“…However, traditional CONC programs can increase cardiopulmonary workload in patients, thus inducing higher ventilation, worsening dyspnea, and increasing oxidative stress. Hence, traditional CONC may affect central pathophysiological mechanisms involved in developing functional limitations in patients with moderate to severe damage associated with SARS-CoV-2 infection and subsequent prolonged hospital stay [ 65 ]. On the contrary, evidence suggests that ECC is a well-tolerated exercise that increases muscle mass gain without significant cardiopulmonary stress, thereby improving the functional capacity of the musculoskeletal system [ 66 ].…”

Diferencia en las distintas funciones de las lipoproteínas de alta densidad en respuesta a la infección por SARS-CoV-2

“…Estas catalizan la reducción de oxígeno a anión superóxido, iniciando la producción de otras especies reactivas del oxígeno (ROS). (7,8). Este es el principal mecanismo que provoca el aumento de estrés oxidativo en pacientes con COVID-19.…”