Symptom variability following acute exercise in myalgic encephalomyelitis/chronic fatigue syndrome: a perspective on measuring post-exertion malaise. Issue 2 (3rd April 2017)

• Record Type: Journal Article
• Authors: Lindheimer, Jacob B.; Meyer, Jacob D.; Stegner, Aaron J.; Dougherty, Ryan J.; Van Riper, Stephanie M.; Shields, Morgan; Reisner, Amanda; Shukla, Sanjay K.; Light, Alan R.; Yale, Steven; Cook, Dane B.
• Is Part Of: Fatigue. Volume 5:Issue 2(2017)
• Page Start: 69
• Page End: 88
• Publication Date: 2017-04-03
• Subjects: Chronic fatigue -- exercise -- post-exertion malaise -- symptoms -- variability; Chronic fatigue syndrome -- Periodicals; Myalgic encephalomyelitis -- Periodicals; 616.047805
• DOI: 10.1080/21641846.2017.1321166
• Languages: English
• ISSNs: 2164-1846

Abstract

ABSTRACT: Background: Consensus for an operational definition of post-exertion malaise (PEM) and which symptoms best characterize PEM has not been established and may be due to variability within and between studies. Purpose: Determine the magnitude of the effect of maximal and submaximal physical exertion on multiple myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) symptoms that are associated with PEM and explore variability among two studies in which mood, fatigue, and pain symptoms were measured before and after exercise. Methods: Symptoms were measured before, and 48 and 72 hours after exercise in study 1 (ME/CFS = 13; Controls = 11) and before and 24 hours after exercise in study 2 (ME/CFS = 15, Controls = 15). Between-study variability was examined by comparing Hedges d effect sizes (95% CI) from studies 1 and 2. Within-patient group variability was examined via inspection of dot density plots. Results: In study 1, large increases in general fatigue (Δ = 1.05), reduced motivation (Δ = 0.93), feelings of fatigue (Δ = 0.90), feelings of confusion (Δ = 0.93), and total mood disturbance (Δ = 0.90) were found at 72 hours. In study 2, a large increase in affective/sensory pain (Δ = 0.79) was found at 24 hours. Dot density plots in both studies revealed substantial variability among people with ME/CFS relative to healthy control participants. Conclusions: PEM symptoms are variable among people with ME/CFS and several gaps in the literature need to be addressed before guidelines for measuring PEM in the clinical or research setting can be established.