Fig. 1: Lower exercise capacity in patients with long COVID.
From: Muscle abnormalities worsen after post-exertional malaise in long COVID
Maximal pulmonary oxygen uptake (V̇O2max, A, n = 23 long COVID, n = 21 healthy control), peak power output (B, n = 25 long COVID, n = 21 healthy control) and gas exchange threshold (C, n = 23 long COVID, n = 21 healthy control) were all lower (p < 0.0001, p = 0.001 and p = 0.014, respectively)in patients with long COVID compared to healthy controls. D and E Muscle deoxygenated [heme] responses (mean ± SD) measured by near-infrared spectroscopy were lower (p = 0.023) in long COVID (n = 16), indicative of lower peripheral oxygen extraction during exercise compared to healthy controls (n = 18; excessive adipose tissue precluded data analysis in remaining participants). Continuous parametric data were analyzed using a two-sided t-test (panels A–C). Continuous parametric longitudinal data (mean ± SD; panels D and E) were analyzed with a generalized linear mixed model. p-values for panel D, E were determined with a two-sided ANOVA test. Dashed line (D) represents the average starting point of the exercise test. *p < 0.05; **p < 0.001. Box plots show the median (centerline), the first and third quartiles (the lower and upper bound of the box), and the whiskers show the 1.5× interquartile range. Source data are provided in the Source Data File.
