Answers for life with ME/CFS. Pace by your body’s numbers, not by guesswork.
Autonomic is a pacing app for ME/CFS on iPhone and Android. Each morning your HRV, resting heart rate and sleep set a budget in hours and minutes that spends down as you move, and every day is checked against the two days after it, because that is when PEM lands. No armband to buy, and all of it stays on your phone.
Every install starts with 14 days of Pro, free
“I’ve been through a dozen apps trying to manage my POTS and PEM. I can say without a doubt Autonomic is the BEST one I’ve tried.”
“It’s already helping me manage my health and gather data to show providers.”
“Only app that isn’t for athlete training and specific to dysautonomia.”
The questions ME/CFS leaves you with, answered.
Each one is a part of the app. Tap a question to see how it works.
ME/CFS, PEM and the energy envelope.
- Defining feature
- Post-exertional malaise
- Crash delay
- 12 to 48 hours
- A crash can last
- Days or longer
- What helps most
- Pacing
Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a long-term illness whose defining feature is post-exertional malaise (PEM): a disproportionate worsening of symptoms after physical, cognitive or emotional effort that would once have been trivial1. It is far more than tiredness. Brain fog, pain, unrefreshing sleep and orthostatic symptoms tend to flare together, and a single overexertion can cost days.
The cruelty is the delay. PEM usually begins 12 to 48 hours after the effort, so you feel more or less fine during the walk, the phone call or the family visit, and pay for it two days later. By the time the crash arrives, its connection to what caused it is gone. Post-exertional malaise, explained goes deeper on why.
Why pacing is so hard to do by feel
The answer to PEM is pacing: staying inside your energy envelope, the amount of activity your body can currently absorb without a crash. But the envelope cannot be felt, it shrinks on bad days, and good days are exactly the ones that tempt you past it. Graded exercise that ignores symptoms is no longer recommended for ME/CFS2, because each push becomes a fresh trigger rather than a step forward. Pacing 101 walks through how people find and hold their envelope.
How Autonomic puts a number on the envelope
- It starts from your morning. HRV, resting heart rate and sleep set today’s budget. A rough night means a smaller one, and that is the point.
- It counts what PEM answers to. Steps, time upright, logged activities, and the minutes your heart spends above your own exertion line, priced by how far above it sat.
- It judges each day on the two days after. That is when the crash shows up, so that is where the budget learns what you can absorb.
- Rest buys some back. Legs up and breathwork return minutes, up to a quarter of what the day cost.
- It stays quiet on a bad day. During a downturn or on a crash day it holds the number back, because a small budget on a bad day is still an invitation to spend it.
Filling the bar is never the goal. Unspent budget is not wasted, and nothing in the app will ever congratulate you for using it all.
What Autonomic will not do
It will not diagnose ME/CFS, prescribe an activity level, or tell you to start, stop or change a treatment. The budget is fitted from your own history. It is not an exercise plan, and it is not a limit set by a clinician.
Sources
Checked November 2026- Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness Institute of Medicine. The National Academies Press, 2015. Post-exertional malaise, and why the crash comes later.
- Myalgic encephalomyelitis (or encephalopathy)/chronic fatigue syndrome: diagnosis and management (NG206) National Institute for Health and Care Excellence. NICE guideline, 2021. Energy management: staying within your energy envelope.
See exactly what today cost you.
Not a mystery number. Every minute is traced back to something you did, and rest buys some back. Sample day.
What to track with ME/CFS, and why.
The signals that move with ME/CFS, and how each one reaches your journal without costing you energy you do not have.
| Signal | What it can tell you | How Autonomic gets it |
|---|---|---|
| Morning HRV | Below your own normal, especially a day or two after a big effort, it is one of the earliest signs that strain is building. | Five minutes lying down, with your phone camera, Apple Watch, Garmin or a chest strap |
| Resting and overnight heart rate | A rate that ticks up over a few days often comes before the crash you feel. | From your morning reading, plus overnight heart rate from Apple Health or Health Connect |
| Heart rate through the day | Minutes above your own exertion line, and how far above, are a more honest measure of load than steps alone. | Read from Apple Health or Health Connect and priced into your pacing budget |
| Steps and upright time | Standing costs energy too, even when you are not moving. | Steps from your phone or watch; standing estimated from your heart rate, and marked as estimated |
| Rest | Legs up, naps, breathwork and lying down, and whether your heart rate actually settled. | Logged in two taps; legs up and breathwork buy back some budget |
| PEM and symptoms | When a crash hits, how long it lasts, and what the two days before it held. | Post-exertional malaise, fatigue, brain fog and more built in, plus any you create |
| Sleep | Unrefreshing sleep is part of ME/CFS, and a broken night means a smaller budget the next day. | Nights arrive from Apple Health or Health Connect, with stages and overnight heart rate |
I’ve been through a dozen apps trying to manage my POTS and PEM. I can say without a doubt Autonomic is the BEST one I’ve tried.
A tap on the shoulder while there is still time.
Alerts can tell you when you are ahead of pace for the time of day, when you are nearly through your budget, or when your heart rate has sat above your own line for a while, naming the bpm. After an over day, a morning note says so. They are paced harder than the budget itself: three a day at most, and never in the night.
The same budget sits on your home screen widgets and, on iPhone, your Apple Watch.
The pacing budget and its alerts are part of Pro. Every install starts with 14 days of it.
Explore the pacing budget →
vsPacing like Visible, without the band.
Visible is the best known pacing app for ME/CFS. Autonomic paces you with what you already own, for less.
Read the full comparison with Visible →
$179.88 a year, or $19.99 a monthVisible Band 2.0, $79.70No, by designPacePoints from the band
“I saw specialist after specialist, and kept leaving with no real answers. So I started tracking it myself. Autonomic is the tool I built to make sense of it.”
Austin Spaeth · more than four years with long COVID · dad of six, South Carolina
Read my story →ME/CFS questions, answered
What is the best pacing app for ME/CFS?+
The one that fits your energy envelope to you, counts the load PEM actually answers to, and does not ask you to buy new hardware. Autonomic gives you a daily budget in hours and minutes, set by your own HRV, resting heart rate and sleep, judged on the two days after each day, and it works from the phone, watch or strap you already have. Everything stays on your phone.
How does Autonomic know my energy envelope?+
It starts on day one from your morning readings, then learns from your history. Each day is judged on the two days after it, because that is when post-exertional malaise lands, and only a real dip in your numbers can lower the ceiling. The strip says it is still learning until it has enough of your days to be fitted.
Does it count mental and emotional exertion?+
Not directly, because no phone can read a hard conversation. Your heart often can: minutes above your own exertion line count wherever they come from, so a stressful afternoon that raises your heart rate is charged like any other effort. You can also log stressful work as an activity.
Do I need an armband or heart rate monitor?+
No armband to buy. The budget works from your steps and what you log, and gets sharper with any watch or strap that writes heart rate to Apple Health or Health Connect. When an estimate is thin, the app says so in words and tells you what would sharpen it.
Will it push me to do more?+
No. The budget is a ceiling, never a target. No alert ever invites you to spend what is left, nothing congratulates you for filling it, and on a downturn or crash day it holds the number back.
Is the pacing budget free?+
The pacing budget is part of Autonomic Pro, $7.99 a month or $49.99 a year, and every install starts with 14 days of Pro with no card. The journal, unlimited HRV readings, crash warnings and your daily score are free forever.
Is my health data private?+
Yes. Your journal lives on your phone, with no account, no ads and no tracking. Every score, budget and insight is worked out on the device.
About pacing and PEM
All recovery articles →The latest on ME/CFS
Know tomorrow’s budget before you spend it.
Free on iPhone and Android. Every install starts with 14 days of Pro, pacing budget included, with no card.