COVID-19 and the impact of physical activity on persistent symptoms

Abstract

Introduction: Physical activity is protective against chronic disease but whether activity is associated with persistent symptoms in non-hospitalized coronavirus disease 2019 (COVID-19) survivors is unknown. The purpose of the study was to determine the impact of the COVID-19 pandemic on physical activity levels and the influence of physical activity on acute COVID-19 and long COVID symptoms in non-hospitalized COVID-19 survivors.

Methods: In total, 64 non-hospitalized COVID-19 survivors (45 female participants, 40 ± 18 years) were assessed for activity levels, body composition, and symptoms of COVID-19 8.5 ± 4.7 months post-infection and categorized into two groups: (1) persistent symptoms and (2) no symptoms at the time of testing. Furthermore, 43 of the 64 participants (28 female participants, 46 ± 18 years) completed a follow-up questionnaire online 51.0 ± 39.7 months (4.25 years) post-infection. A subset of 22 COVID-19 survivors (16 female participants, 35 ± 16 years) were matched for age, sex, and body mass index with healthy controls. Physical activity was quantified using (1) self-reported questionnaire (International Physical Activity Questionnaire; IPAQ-SF) at three time periods; prior to COVID-19 infection, at the time of laboratory testing (8.5 ± 4.7 months after infection), and during an online follow-up (51.0 ± 39.7 months, i.e., 4.25 years after infection); and (2) 7 days of wearing an ActiGraph accelerometer following laboratory testing.

Results: Physical activity (IPAQ-SF) declined in COVID-19 survivors from pre-COVID-19 infection to 8.5 ± 4.7 months after infection [3,656 vs. 2,656 metabolic equivalent of task (MET) min/week, 27% decrease, p < 0.001, n = 64] and rebounded to levels similar to pre-COVID-19 infection at 4.25 years after infection (p = 0.068, n = 43). Activity levels quantified with accelerometry did not differ between COVID-19 survivors and controls. However, COVID-19 survivors who reported persistent symptoms 8.5 months after infection (n = 29) engaged in less moderate-vigorous physical activity and steps/day than those without persistent symptoms (n = 27) (37 vs. 49 MET min/day, p = 0.014 and 7,915 vs. 9,540 steps/day, p = 0.014).

Discussion: Both COVID-19 survivors and matched controls reported reductions in physical activity indicating that lower levels of activity were likely due to the pandemic rather than COVID-19 infection alone. However, those who were most affected by COVID-19 infection with persistent symptoms had the greatest reductions in physical activity, even at ∼8 months and ∼4 years post-infection.

Keywords: COVID-19; accelerometer; fatigue; healthy control; long COVID; persistent symptoms; physical activity.

Figure 1

COVID-19 symptoms at the time of infection and post-infection. COVID-19 symptoms reported by the COV participants (% of participants) at each time point: at the time of acute infection (black), persistent symptoms at 8.5 months (light gray), and persistent symptoms at 4.25 years (dark gray). (A) Symptom prevalence reported by the 64 COV participants at the laboratory session and (B) symptom prevalence reported by the 43 COV participants who participated in the follow-up survey.

Figure 2

Self-reported physical activity over time of the COV participants. Shown are vigorous and moderate PA, walking, and total METs min/week quantified from the self-reported IPAQ-SF questionnaire for 43 COV participants. Shown are the mean ± SD for all graphs except for total METs, which is presented as a median and interquartile range for each time point: pre-COVID-19 infection (striped), 8.5 months later at the laboratory session (black), and 4.25 years later at the online follow-up survey (gray). The solid lines show the unadjusted effect between individual time points with statistical significance; ns = p > 0.05; *p ≤ 0.05; **p ≤ 0.01; ***p ≤ 0.001; ****p ≤ 0.0001.

Figure 3

Sex differences in self-reported physical activity. Shown are vigorous and moderate PA, walking, and total METS quantified from the self-reported IPAQ-SF questionnaire for COV participants: 45 female and 19 male participants. Shown are the mean ± SD for all graphs except for total METs, which is presented as a median and interquartile range, where female participants are represented by the darker bars and male participants are represented by the lighter bars at pre-COVID-19 infection (striped) and 8.5 months later at the laboratory session (solid). The solid lines above show the preliminary unadjusted between-subject effect of sex with statistical significance; ns = p > 0.05; * p ≤ 0.05; **p ≤ 0.01.

Figure 4

Self-reported physical activity between COV participants with and without persistent symptoms. Shown are vigorous and moderate PA, walking, and total METS quantified from the self-reported IPAQ-SF questionnaire for COV participants: 34 with persistent symptoms at 8.5 months and 30 with no symptoms at 8.5 months. Shown are the mean ± SD for all graphs except for total METs, which is presented as a median and interquartile range, where the COV participants with persistent symptoms are represented by the darker bars and COV participants without symptoms are represented by the lighter bars at pre-COVID-19 infection (checkered) and 8.5 months later at the laboratory session (solid). The solid lines above show the preliminary unadjusted between-subject effect of sex with statistical significance; ns = p > 0.05; *p ≤ 0.05.

Figure 5

Comparison of accelerometry between the COV and CON participants. Shown are sedentary, light PA, MVPA, and step counts per day measured by accelerometry for 22 CON participants (dark gray), 8 COV participants without any symptoms at the laboratory session (black) (8.5 months after infection) and 14 COV participants with persistent symptoms at the laboratory session (light gray) (8.5 months after infection). Shown are the mean ± SD for all graphs.