Author(s): WIEWELHOVE, T., EMMEL, C., SCHNEIDER, C., EIßMANN, M., BRUDER, O., SCHMIDT, B., Institution: IST UNIVERSITY OF APPLIED SCIENCES, Country: GERMANY, Abstract-ID: 176

INTRODUCTION:
The aim of the present pilot study was to assess the feasibility and general efficacy of a twelve-week individualized aerobic exercise training intervention for patients with persistent symptoms following a SARS-CoV-2 infection (long COVID syndrome).
METHODS:
A total of 62 individuals with persistent symptoms, including respiratory issues, headaches, and concentration problems, 12 months post SARS-CoV-2 infection, were randomized into the intervention or control group, stratified by age and sex. Following initial assessments and detailed training consultations, the intervention group underwent a 12-week unsupervised aerobic endurance training intervention. The control group was instructed to maintain their existing activity levels at the time of the initial assessment for 12 weeks without engaging in additional systematic training. Both groups documented each training session using monitoring software. After 12 weeks, both groups underwent a final assessment. Self-reported health parameters (e.g., severity of persistent symptoms after SARS-CoV-2 infection), body composition (including muscle and fat mass), and spiroergometric and performance-related measures (e.g., VO2max and W at ventilatory thresholds 1 and 2) were recorded during the initial and final assessments. Out of the initially randomized 62 individuals, a total of 54 were included in the final analysis due to dropouts. The analysis was conducted as an intention-to-treat, per-protocol, and as-treated analysis, as well as using regression methods (difference-in-differences approach [DID]).
RESULTS:
The calculated confidence intervals from the DID showed no clinically relevant differences in the changes of measured parameters between the groups. The calculated effect sizes from the DID revealed small to moderate positive effects on various self-reported health parameters favoring the endurance training intervention, but no effects on body composition and spiroergometric measures. When comparing analysis principles, fewer positive effects on various self-reported health parameters were observed in the per-protocol analysis compared to the intention-to-treat and as-treated analyses. The effects on body composition and spiroergometric measures did not differ based on the analysis principle. Training monitoring indicated low adherence.
CONCLUSION:
An unsupervised endurance training program had a slight positive impact on relevant health perception parameters in individuals with persistent symptoms after SARS-CoV-2 infection. Regarding changes in physiological and subjective health and performance markers, the intervention showed neither efficacy, likely partially attributed to low adherence, nor harm.