“I’m exhausted, I must have chronic fatigue.” Most of us have said something like it. But Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is not a rough week you bounce back from with a good sleep. It’s a chronic illness that can reshape a person’s whole life, and the latest research confirms it has biological roots.
The DecodeME project is the largest genetic study of ME/CFS to date. Comparing the DNA of more than 15,500 people with ME/CFS against around 259,000 people without it, the first results (published in 2025) found differences in eight regions of the genome, many tied to the immune system, the nervous system, and how the body responds to infection. In short, the exhaustion isn’t “in someone’s head.” It has measurable biological signatures (The Guardian, 2025).
What makes ME/CFS different
Everyone gets tired, and usually rest fixes it. ME/CFS is not that. The exhaustion is deeper, it doesn’t lift with sleep, and small tasks like getting dressed or holding a conversation can feel like too much.
The symptom that sets ME/CFS apart is post-exertional malaise (PEM): a disproportionate crash after physical or mental effort, often delayed by a day or two and lasting days or weeks. Alongside it, people commonly live with brain fog, unrefreshing sleep, pain, and orthostatic intolerance (feeling dizzy or unwell on standing). Symptoms fluctuate, which makes the illness hard to predict and hard to plan around.
Why the DecodeME findings matter
For years, people with ME/CFS were told it was stress, low mood, or a lack of effort, and some were pushed to exercise their way out of it, which often made them worse. DecodeME won’t deliver a cure or a single test tomorrow. What it offers now is validation: clear evidence that the illness is real and not anyone’s fault, and a reason for clinicians to take it seriously. In our clinic, that recognition alone often brings real relief.
Managing ME/CFS: pacing, not pushing
The most damaging myth about ME/CFS is that you can push through and build your stamina back up. For a condition defined by PEM, pushing backfires. It drives the boom-bust cycle: a good day, too much done, then a crash that costs days or weeks.
To be clear, I do not recommend Graded Exercise Therapy (GET), which increases activity on a fixed schedule regardless of symptoms. The approach that holds up is pacing: learning your limits and spreading effort so you avoid the crash. In practice that can mean breaking tasks into smaller steps, resting before and after activity, tracking exertion (heart rate can help), and building routines around your own energy pattern.
Where an exercise physiologist fits
Movement can help, but only the right kind, at the right pace. Too much too soon triggers setbacks; too little costs strength and confidence. Our job isn’t to run you through hard workouts. It’s to help you find safe, sustainable ways to move within your current capacity, adjust as your energy shifts day to day, and rebuild confidence after past crashes, working alongside your GP and other practitioners. The goal isn’t to chase a cure. It’s to help you live as well as possible within the energy you have.
If ongoing fatigue is holding you back, you don’t have to work it out alone. We’re here to help you find practical steps forward.
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