Cort Johnson – Health Rising
A few things to keep in mind:
- Participants were well enough to complete two demanding exercise tests, so results may reflect the milder end of the ME/CFS spectrum rather than the experience of those who are more severely affected.
- This is early-stage, mechanistic research — it doesn’t change current pacing or activity advice, and isn’t a green light to push through exertion.
- As always, this is general research information, not medical advice. Please talk to your own doctor before changing how you manage activity or exercise.
Recent research led by Dr Maureen Hanson and her team looked at how the body’s proteins respond to exercise stress tests in people with ME/CFS compared with healthy controls. Rather than finding evidence of muscle damage after exertion, the study suggests something quite different, and potentially important for understanding PEM.
Key findings:
- At rest, individual protein levels weren’t dramatically different, but when groups of related proteins were examined together, significant differences in biological pathways appeared.
- Important pathways involved in T-cell signalling (part of the immune system) were reduced in people with ME/CFS at baseline and after exercise, suggesting the immune system may be less responsive or ‘exhausted’.
- Healthy controls showed changes in many more proteins after exercise than people with ME/CFS, which indicates that the normal biological response to exertion is reduced in ME/CFS.
- Exercise appears to trigger inflammation and oxidative stress that may reduce blood flow to muscles, but not through the classic muscle damage seen in healthy exercise responses. Instead, the body’s normal muscle repair processes seem to be impaired.
- The most significant disruptions were found around 24 hours after exertion, a time when post-exertional malaise is often most intense, suggesting a faulty repair response may underlie PEM rather than structural damage to muscle fibres.
What this might mean:
This research supports the idea that ME/CFS isn’t simply about being out of shape or having muscle damage, but about how the body’s systems, particularly immune and repair pathways, respond (or fail to respond) to stress. It aligns with the experience many of us have where symptoms worsen after activity despite there being no obvious tissue injury.
The findings point toward biological differences in how energy production, immune activation, and recovery processes are regulated after exertion, offering a new perspective on why PEM happens and where future treatments might target.
Health Rising article can be found at Healthrising
From the study:
Germain A, Glass KA, Eckert MA, Giloteaux L, Hanson MR. Temporal Dynamics of the Plasma Proteomic Landscape Reveals Maladaptation in ME/CFS Following Exertion. Mol Cell Proteomics. 2025 Dec;24(12):101467. doi: 10.1016/j.mcpro.2025.101467. Epub 2025 Nov 17. PMID: 41237904; PMCID: PMC12757482
