Cardiopulmonary exercise testing and post-exertional malaise in ME/CFS: A retrospective analysis
Staci R. Stevens, Christopher R. Snell, Jared N. Stevens et al. · Journal of Translational Medicine · 2018 · DOI
Quick Summary
ME/CFS patients underwent two consecutive days of cardiopulmonary exercise testing (CPET). On the second day, patients showed significantly reduced VO2 max and anaerobic threshold compared to the first day — and compared to healthy and disease controls who recovered normally. This objective impairment matches the subjective PEM experience.
Why It Matters
Two-day CPET is the only validated physiological test that objectively demonstrates PEM. This study provides objective evidence that ME/CFS patients cannot recover from exertion the way healthy people or those with other chronic illnesses do. It has important implications for disability assessments.
What This Study Does Not Prove
The two-day CPET does not prove the mechanism of PEM. It cannot tell us why ME/CFS patients fail to recover, only that they demonstrably do not.
Topics
Tags
Metadata
- DOI
- 10.1186/s12967-018-1397-7
- Case definition
- Canadian Consensus Criteria (CCC)
- Sample size
- 51 patients
- Control group
- Yes
- Review status
- Editor reviewed
- Evidence level
- Replicated human evidence from multiple independent studies
- Last updated
- 7 April 2026