Effects of a 24-week multicomponent training program on functional capacity, persistent symptoms, body composition, and physical activity in patients significantly affected by COVID-19: the COVID-19 and REhabilitation study (CORE-study)-randomized clinical trial

Abstract

Background: COVID-19 can lead to reduced functional capacity, loss of muscle mass, and lasting and persistent symptoms, resulting in reduced physical activity.

Objective: To evaluate the effects of a multicomponent training on functional capacity, persistent symptoms, body composition, pulmonary function, and physical activity levels in patients significantly impaired by SARS-CoV-2.

Methods: The participants were randomly assigned (1:1) to either the intervention group (IG), which received multicomponent training (balance/aerobic/resistance), or the control group (CG). Functional capacity [6 min walk test (6MWT)-primary outcome, sit and reach, sit-to-stand, timed up and go], persistent symptoms (dyspnea, fatigue, post-COVID functional status, frailty), body composition (dual-energy x-ray absorptiometry and bioimpedance), pulmonary function, and physical activity levels (accelerometry) were evaluated at baseline and after 24 weeks. Generalized estimating equations were used, with the significance level set at α = 0.05. Outcomes were analyzed by intention-to-treat (ITT) and per-protocol (PP) approaches. Effect sizes were calculated from the mean difference between groups of changes between pre- and post-intervention.

Results: Forty participants [age = 52.00 (12.93) years, 19 women] were included. The primary outcome 6MWT showed improvement in both groups in the ITT analysis (IG: 35.5 m, 95% CI: -3.0 to 74.1; CG: 37.4 m, 95% CI: -5.26 to 80.2) and in the IG (87.6 m, 95% CI: 50.6-124.4) in the PP analysis. The IG showed a reduction in mental fatigue (-1.7 points, 95% CI: -0.5 to 3.5) and general fatigue (-6.5 points, 95% CI: -9.4 to -3.5) in our ITT analysis. The IG also revealed improvement in timed up and go test (-1.6 s, 95% CI: -2.6 to -0.6), mental fatigue (-2.0points, 95% CI: -3.6 to 0.7), general fatigue (-6.4points, 95% CI: -11.0 to -1.6), and a protective effect against increased body fat in PP analysis.

Conclusion: This program was effective in improving fatigue in patients previously significantly affected by COVID-19.

Keywords: COVID-19; SARS-CoV-2; physical capacity; physical exercise; rehabilitation.

Figure 1

Structuring of training sessions throughout the rehabilitation program (CORE-study). RPE, rate of perceived exertion; MR, maximum repetitions.

Figure 2

Flow of the participants through the study.

Figure 3

(A) Results of the 6MWT in the PP analysis. (B) Results of the 6MWT in the ITT analysis. *Different values between baseline and 24 weeks. Different letters indicate differences between groups at baseline.

Figure 4

(A) Results of the Chalder scale—physical domain in the PP analysis. (B) Results of the Chalder scale—physical domain in the ITT analysis. *Different values between baseline and 24 weeks.

Figure 5

(A) Results of the Chalder scale—mental domain in the PP analysis. (B) Results of the Chalder scale—mental domain in the ITT analysis. *Different values between baseline and 24 weeks. Different letters indicate differences between groups at baseline.

Figure 6

(A) Results of the Chalder scale—general fatigue in the PP analysis. (B) Results of the Chalder scale—general fatigue in the ITT analysis. *Different values between baseline and 24 weeks. Different letters indicate differences between groups at baseline.