ABSTRACT
The purpose of this study was to determine (1) whether pulmonary function is reduced, and airway reactivity is increased after recovery from COVID-19 in individuals who did not have severe illness, and (2) whether physical activity levels had any impact on pulmonary function or airway reactivity. An exploratory aim of the study was also to assess whether number of symptoms was associated with pulmonary function outcomes. The maximal flow volume loop was used to measure pulmonary function in individuals who had previously tested positive for COVID-19 (COV; n = 20, 23.0 ± 5.4 years) and those who had not (CON; n = 20, 23.7 ± 5.5 years) before and after a hypertonic saline challenge (HSC) designed to increase airway reactivity. Self-reported symptoms and physical activity levels (MET (min/week)) were collected to examine their correlation with pulmonary outcomes. There were no significant differences in any pulmonary function outcomes between the COV and CON groups before or after the HSC. There were also no associations between physical activity and pulmonary function outcomes. However, among participants who reported greater than four symptoms, there was a larger decline in forced expiratory volume in 1 s divided by forced vital capacity following HSC (p = 0.035). Pulmonary function and airway reactivity are not impacted after recovery from COVID-19 in young individuals; however, it appears that the number of symptoms reported may be associated with increased airway reactivity even after recovery in young adults who were not hospitalized with the virus.