iPhone + Apple Watch  ·  POTS  ·  Beta now open

Was yesterday too much?

Your watch already recorded how last night went. Downshift reads it in the morning, while you can still do something with it.

Join the beta Get notified at launch
Downshift on iPhone. Reserve reads 28 on the dial. Below it, Load at 13,275 beat-min and the evening check-in logged as good.
The one idea

Every night, your body is supposed to downshift.

Heart rate drops to its floor and holds there, and the night goes to repair.

With POTS, that shift is unreliable. Some nights it comes late. Some nights it barely comes at all. The morning after can feel like energy. It's adrenaline.

So you take the day like you have it, and that day stacks on a night that never cleared. You feel it two days later, with nothing in between that explains it.

The score tells you what you are carrying, not what you are capable of.

Same bedtime. Two different nights.

Sample nights
11 PM1 AM3 AM5 AM7 AM 6254
Downshifted early · floor 54 by 1 AM, held Downshifted late · floor 62 after 5 AM
A day with Downshift

One night. One stand test. One number.

No extra hardware. Your watch records the night on its own. The stand test is the one thing you do yourself. Everything else is reading it alongside what you already know.

OvernightAutomatic

Wear the watch to bed.

Heart rate, HRV, sleep and breathing land in Apple Health overnight. Downshift reads them when you wake. Nothing to press.

First thingYou

Stand up once.

Thirty seconds seated, two and a half minutes standing, first thing. The one input the watch can't take for you.

After the testReserve

Read the number.

Reserve, read alongside your own morning check of how you slept and how you feel.

EveningYours only

Log the day.

One tap for how it felt, and a text box. The app never reads the diary. It is there so that weeks later you can find your own note about the night before.

Your body downshifted late last night. Yesterday may have been too much. You know what helps on days like this.

Some of yesterday is still here.

Your body absorbed yesterday cleanly. Whatever that day was, it worked.

Example mornings, not your data. The small ring is Standard Recovery.
Reserve

How completely, and how early, your body downshifted last night.

A crash answers that question two days late. Reserve answers it this morning.

Green means nothing was carried in.

Any strain today is from today. You can still have a bad POTS day on a green morning, because you still have POTS. Whatever happens is not yesterday's fault. Green is not permission.

Mid means some of yesterday is still here.

Partial clearance. The plain reading and nothing more. It is the score most often misread as getting better.

Low means the body downshifted late, or did not hold it.

Yesterday may have been too much. Downshift names when, never why. It hands you the question, because you were there.

Zero is the bottom of your own range, not an alarm state. There is no reading the app withholds.

What went into it

Five inputs. Only one you do yourself.

Reserve opens up. One tap down, every input is listed with the night it came from, in the same words used everywhere else in the app.

  • Heart rateovernight capture
  • Heart rate variabilityovernight capture
  • Sleepovernight capture
  • Respiratory rateovernight capture
  • Stand testyou
Apple Health
Downshift

Your watch writes the first four to Apple Health. Downshift reads them and never writes anything back.

Three cards from Reserve's input breakdown: Nightly HRV as green dots around an average of 74 ms, Morning stand test as orange stems with a median of +18 bpm, and Load as bars colored by that day's score.
The stand test

The night shows whether your body downshifted. The stand test shows whether it held.

Thirty seconds seated. Two and a half minutes standing. First thing, before anything else. Not because mornings are better. Because they are the same. Same night behind you, same chair, same routine.

Spike, last 14 mornings

median +18 bpm
Sample data▾ trending down
7:41 AM
+18 bpm · 68 seated · trending down · feeds Reserve
53
68seated
+18spike
trending downexit

Sample test. Hover the curve to read it. Collapse and expand the card the way it works in the app.

Reading the zones

Seated

The baseline. Thirty seconds sitting still. The dashed line is your seated heart rate, and everything after is measured against it.

Zone 1

The spike. The first forty-five seconds on your feet. How far it jumps, and how fast. The same jump a clinic stand test looks for, recorded every morning.

Zone 2

The hold. Forty-five seconds to two and a half minutes. Whether the rate settles back toward seated or stays up. The shaded area is how far above seated it sat.

Exit

The direction it was heading. Trending down means the body was catching up. Sustained means it held where it was. Trending up means it was still climbing when the test ended.

The first test after waking feeds Reserve. A second test the same day is recorded but unscored, so the conditions match day to day. A morning without a test is reported as a gap, in the same voice as a full one.

Reserve 28. Standard Recovery 68%. A body in a recovery state, not a recovered one.

Reserve 74. Standard Recovery 78%. When the two sit close, they are telling the same story.

Example mornings, not your data.
Standard Recovery

The small ring is the number other apps give you.

Standard Recovery is the industry-standard overnight recovery score, the kind wearables like WHOOP show every morning. WHOOP describes its version as built from overnight heart rate variability, resting heart rate, respiratory rate, sleep, skin temperature and blood oxygen1. Downshift puts it on the same dial so you don't need a second app to see it. Reserve is the number Downshift stands behind. Here is why.

POTS shows up when you stand.

POTS is diagnosed by how far your heart rate rises on standing: at least 30 beats per minute in adults, or 40 in adolescents, within ten minutes2. An overnight recovery score is measured while you lie still, so it never sees that. The morning stand test does, every day, and it goes into Reserve.

A high HRV is not always a recovered body.

In triathletes deliberately overloaded into functional overreaching, researchers found parasympathetic activity went up, not down3. A body working hard to recover overnight can post a good HRV while it is still carrying the day before.

Apple Watch reads HRV in brief, still moments.

Apple samples HRV only while you are still, so the number of readings changes from night to night4. On my own watch that has meant as few as three to six readings in a night. Reserve never lets one great reading decide the morning. HRV confirms. It doesn't vote alone.

When the floor arrives says more than how low it goes.

Reserve's main overnight signal is when your heart rate reaches its floor and whether it holds. In my own data, settled nights reached the floor by 1 to 3 AM. Before a crash, it came at 8 to 10 AM, or not at all. Published studies show evening alcohol and hard exercise both change heart rate and HRV through the night5,6. My numbers are one person's data, which is why the beta matters.

Keep Standard Recovery if it earns its place. Turn it off in Settings if it doesn't.

  1. WHOOP for Developers, WHOOP 101
  2. Johns Hopkins Medicine, Postural Orthostatic Tachycardia Syndrome
  3. Le Meur Y, et al. Evidence of parasympathetic hyperactivity in functionally overreached athletes. Med Sci Sports Exerc, 2013
  4. Apple Support, Monitor your heart rate with Apple Watch
  5. Pabon E, et al. Effects of alcohol on sleep and nocturnal heart rate. Alcohol Clin Exp Res, 2022
  6. Myllymäki T, et al. Effects of exercise intensity and duration on nocturnal heart rate variability and sleep quality. Eur J Appl Physiol, 2012
Over time

The number is the surface. Attribution is the product.

After enough mornings you can confirm which days your body absorbs and which it does not. Then you go looking for what else made a morning low. Downshift cannot see those things. It can tell you which mornings to look at.

Four weeks of mornings, next to your own notes

Illustration

Each square is one morning's Reserve. A dot means you wrote a note that evening. The morning after a day is the next square. Tap any morning.

What you can tolerate

The same leg day, two weeks apart.

The first leg day in a month came on a 74 morning, and the morning after read 29. Green was not permission. Two weeks later, the same forty minutes with salt, fluids and compression first read 80 the next morning. Downshift cannot see what changed. You were there, and you wrote it down.

Whether a change is here to stay

A new routine, read week by week.

The routine started at the end of week 2. One low morning still came through in week 3, after a long grocery line. By week 4, the weeks were holding. If the low mornings had kept coming back, that would say not yet. The mornings after show you which.

The first two weeks

Nothing is scored until fourteen clean mornings are in.

9 of 14

Downshift learns your range before it gives you a number. Until then, Reserve shows a range. Nights already in Apple Health count. A counter is the app working, not the app broken.

A year in

It is meant to fade.

You open it less, and trust it when you do. It matters again around a change, a new medication or a new job, and when the mornings slide while you are doing everything right. That is invisible from inside one day. Over weeks, it is hard to miss.

Why it exists

Made by a 22 year old with POTS who was sick of being the last to know.

"Looking back, the data had the pattern before I could feel it."Nate · Built Downshift · Has POTS

Hey, I'm Nate. I didn't grow up thinking anything was wrong with my body. I was athletic and competitive, straight A's. Then sixth grade came and things slowly changed. My teachers' voices blurred into a murmur. I couldn't focus. I thought it was ADHD, then stress, then burnout. Eventually I was wired at midnight and struggling to pick up my bag and get to school. The worst part was that it never turned off. I could not downshift. That is where the name comes from.

I never saw it as a physical problem. I was still playing baseball, swimming, lifting. I had no idea the hot showers that left me lightheaded were pushing my heart rate into the 150s, or why my feet turned bright pink, or why lying down fixed everything. Then my dad came across POTS and pushed me to get tested. My heart rate doubled during the test. Weird as it sounds, the diagnosis was a relief. For the first time I knew it was real.

Knowing what to do about it took longer. I did the CHOP protocol, drank the electrolytes, tried medication. Every time I started feeling better, I pushed harder. Then I crashed again. I kept treating POTS like athletic training, where pushing through discomfort makes you stronger.

Here's what finally got me. I made it back to the gym and started working full time as an automotive technician, on my feet all day, telling myself the standing was cardio. My recovery score kept coming in low even though I was sleeping, hydrating, wearing compression. And because all I saw was a number with no story behind it, I stopped paying attention. I didn't need another generic score. I needed something that could read the whole night, the timing, the settling, the stand test, and show me the mornings when my body had stopped keeping up.

So I built it. I've been taking systems apart my whole life. RC cars, drones, 3D printers, eventually the top end of my 1984 Porsche 944. Downshift is that same mindset pointed at POTS. It's the app I wish I'd had when I was younger. It's also why I want beta testers, because real data from real POTS bodies is what checks my work.

Articles

For the questions that come before the app.

Written by Nate, from living with POTS, with sources for every clinical claim.

6 min read

How to tell if a workout was too much with POTS

Why you usually can't tell on the day, and what the night after and the morning stand test show instead.

Read the article 7 min read

POTS exercise programs: CHOP, Levine and Dallas, explained

What the two published programs say, side by side, and how to tell week by week whether the training is being absorbed.

Read the article
Questions

The short answers.

What Downshift is, what it needs, and what it does not do.

What is Downshift?

A pacing tool for POTS and long COVID. It reads last night from your Apple Watch and your morning stand test, and gives you one number, Reserve. Reserve tells you what you are carrying into today, not what you are capable of.

What do I need to use it?

An iPhone and an Apple Watch you wear to bed. There is no extra hardware to buy.

What is the stand test?

Thirty seconds seated, then two and a half minutes standing, first thing in the morning. Downshift records your seated heart rate, the spike when you stand, and the direction it was heading at the end. It is the one input you do yourself.

Is Downshift a medical device?

No. It diagnoses nothing, treats nothing, and does not tell you what to do. It measures you only against your own range.

Can I try it now?

Yes. The beta is open to a small group through TestFlight, Apple's beta app. You need an iPhone and an Apple Watch. Pick Early access and beta testing in the form below and your invite comes by email. Reserve shows a range for the first fourteen mornings, so your baseline is not set during one bad stretch.

How long until I get a score?

Fourteen clean morning stand tests. Until then, Reserve shows a range and a counter shows how far off the number is. Nights already in Apple Health count toward it.

Does it change my Apple Health data?

No. Downshift reads heart rate, heart rate variability, sleep and respiratory rate from Apple Health and never writes anything back.

Does it work for long COVID?

It is built around POTS. Overnight heart rate settling, the timing of the nightly low and the standing heart rate response are studied in both POTS and long COVID, and Downshift reads each of them against your own range.

How much does it cost?

Downshift is free at launch.

Beta now open · Free at launch

Wear the watch to bed tonight.

When you wake, last night is already on Home.