Physical activity and long COVID symptoms

In a recent study published on medRxiv* preprint server, researchers assessed associations between physical activity and symptoms of the long-lasting coronavirus disease (COVID).

Study: Symptom variation, correlations and relationship with physical activity in Long Covid: an intensive longitudinal study. Image Credit: Donkeyworx / Shutterstock

Background

Post-acute sequelae of COVID 2019 (COVID-19) (PASC), long COVID or post-COVID syndrome is a heterogeneous condition that accompanies rapid infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The main symptoms of post-COVID syndrome include cognitive dysfunction, fatigue and shortness of breath, although a wide range of other symptoms are also common and may be prevalent in some patients.

Because studies have used varying standards for symptoms and timestamps, the prevalence of post-COVID syndrome is currently unknown. Nevertheless, recent data from the United Kingdom (UK) shows that 1.2 million people, or 1.9% of the population, have chronic symptoms for more than 12 weeks after acute SARS-CoV infection. -2 and that approximately 20% of individuals experience symptoms that significantly limit their ability to carry out daily activities. Additionally, people with long-lasting COVID have many symptoms that differ between and within individuals over relatively small time intervals.

About the study

In the present article, scientists attempted to characterize the real-time links between discrete PASC symptoms and physical activity and symptoms at the individual level. The team conducted an intensive long-term analysis of 82 people who had self-documented long COVID for about 12 to 18 months.

The objectives of the study were to measure the intra-individual variance of PASC symptoms. Additionally, assess the real-time relationships of various long-lasting COVID symptoms in the setting of daily life. Finally, analyze the strength of the link between symptoms and self-documented activity demand and unbiased physical activity.

Heat map of unadjusted correlations between symptoms at the individual participant level.  The figure shows only participants who experienced all relevant symptoms at a sufficient level to be included in the correlation analysis.

Heat map of unadjusted correlations between symptoms at the individual participant level. The figure only shows participants who experienced all relevant symptoms at a sufficient level to be included in the correlation analysis.

Data was collected using a smartphone app with five daily entries over two weeks and constant use of a wrist accelerometer. Data items included perceived needs in the previous period in Likert scales and seven symptoms in visual analog scales. Average acceleration was used to measure activity in the three-hour period before and after entering application data. Intra-individual associations of symptom matches and individual and clustered symptom circuits produced by graphical vector autoregression were used in the analysis.

Based on an embodied predictive interoceptive coding (EPIC) model of symptoms, the authors hypothesized that strong and consistent patterns of connection between groups of symptoms or between symptoms, efforts, and activities might indicate accurate interoception of pathophysiological processes affecting body organs/systems. . Moreover, poor or inconsistent associations might suggest that impaired interoception and symptom processing worsen the pathophysiological mechanisms of PASC.

Results and discussion

The results of the study indicated that application data from 74 subjects, i.e. 90% of the research volunteers, were suitable for analysis, with 4022 entries reflecting 77.6% of all potential entries. Long COVID symptoms differed significantly from person to person and were only marginally associated. The highest between-participant symptom associations were observed for fatigue and pain with a partial coefficient of 0.5, and cognitive problems and dizziness with a partial coefficient of 0.41.

Pooled within-subject comparisons demonstrated that fatigue was related to cognitive problems (partial coefficient: 0.2), pain (partial coefficient: 0.19), shortness of breath (partial coefficient: 0.15) and dizziness (partial coefficient: 0.12), not anxiety. Cognitive impairment was related to dizziness and anxiety with partial coefficients of 0.17 and 0.16, respectively.

Heatmaps of individual participant associations and symptom circuits revealed no identifiable unique phenotypic patterns. However, long COVID symptoms, such as fatigue, were unpredictably linked to previous or successive physical activity, suggesting that activity levels may adjust based on symptoms. Seven subjects had symptoms that later worsened after the peak of maximal activity.

Symptoms related to the peak period of physical activity.  Bold lines indicated participants (n = 7) in whom the rolling mean z-score (for fatigue or general malaise) was ≥ 1.3 between 12 and 60 hours after the peak.  The light lines represent the other participants.  Smoothed regression line fitted to data from the 7 participants only.

Symptoms related to the peak period of physical activity. Bold lines indicated participants (n = 7) in whom the rolling mean z-score (for fatigue or general malaise) was ≥ 1.3 between 12 and 60 hours after the peak. The light lines represent the other participants. Smoothed regression line fitted to data from the 7 participants only.

conclusion

The present intensive longitudinal research on symptoms and physical activity in PASC has illustrated that symptoms of long COVID fluctuate in people over short periods of time and that patterns of symptom association vary from individual to individual. other. Concurrent associations between symptoms and assessed physical activity were minimal, although a small proportion of participants experienced a delayed peak of symptoms after a peak of activity. The study results quantify patients’ feelings of unpredictability due to previously reported challenges of living with post-COVID syndrome. Furthermore, the findings were consistent with impaired central symptom processing as an additional component in Long COVID.

It should be noted that the investigators used well-established methodologies for data collection and the smartphone app had high completion rates. Additionally, the team noted that self-reporting with visual analog scales on a mobile app gives users more control over their data and decreases the potential for bias when filling in the scales later or with a scientist. In particular, patients were involved in the development of the application and the evaluation of the data. A mix of idiographic (for inside the person) and nomothetic (between people) approaches were applied, including state-of-the-art graphical vector autoregression modeling.

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be considered conclusive, guide clinical practice/health-related behaviors, or treated as established information.

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