Fatigue isn't just tired.
Map your patterns.
ME/CFS and chronic fatigue are defined by post-exertional malaise (PEM) — symptoms that worsen after exertion, sometimes 24–72 hours later. Tracking exertion, sleep, and symptoms separately is the only way to see the delayed pattern.
Today's log
May 2, 2026
Context for today
Built for Chronic Fatigue
Symptoms
Context factors
How it helps with Chronic Fatigue
See PEM lag clearly
Post-exertional malaise often appears 24–72 hours after the exertion. Daily tracking with date-shifted activity context makes the lag visible.
Find your energy envelope
Over weeks of data, the activity level that triggers PEM becomes clear. Stay below it most days; track the days you exceed it.
Document for benefits or workplace
ME/CFS often requires documentation for disability claims or workplace accommodation. A 90-day exported report shows the burden quantitatively.
Questions people actually ask
- What's the difference between fatigue and ME/CFS?
- Everyday tiredness improves with rest. ME/CFS fatigue is severe, persistent, and worsens after exertion — that's called post-exertional malaise (PEM). Tracking PEM separately from baseline fatigue is the most useful single change you can make.
- How do I track post-exertional malaise (PEM)?
- Log exertion (physical, cognitive, or emotional) on the day it happens, and track fatigue/PEM intensity for the next 3 days. After a few weeks the lag pattern becomes visible — many people see PEM peak around 24–48 hours later.
- What's an "energy envelope"?
- The activity level you can sustain without triggering PEM. It's individual and changes over time. Daily logging helps you find yours and notice when it shifts.
- Is this useful for fibromyalgia or long COVID?
- Both overlap significantly with ME/CFS in tracking needs. We have a separate fibromyalgia guide if pain is your dominant symptom; long COVID isn't a separate guide yet, but ME/CFS-style tracking applies.
- How much detail should I log if I'm too exhausted to track?
- Just one intensity slider per symptom is enough. No need to write notes. The whole point is making tracking sustainable on bad days — a 10-second entry is fine.
- How do I share data with a doctor who doesn't take ME/CFS seriously?
- A printed 90-day report with quantified symptom intensity, PEM lag, and activity correlations is harder to dismiss than verbal descriptions. The visual calendar makes the chronic, daily nature of the condition immediately obvious.
Start tracking Chronic Fatigue today.
Free forever. No password. Set up in under two minutes.
Get started — it's free →Sign in with a magic link. Your data stays yours.
General information based on patterns commonly reported by people with this condition. Not medical advice. Talk to your doctor about your symptoms and any tracking-derived patterns before making care decisions.