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WHOOP Cycles

Objective: To explain how WHOOP defines a day cycle and explain multi-day cycles in an easily digestible manner for external use.

What defines a physiological day within WHOOP?

It’s important to note that WHOOP does not define a physiological day as 12am - 12am. Instead of running on a 24 hour clock, a physiological day with WHOOP begins the moment you fall asleep one night, and ends the moment you’ve fallen asleep the following night. This allows WHOOP to calculate all your metrics during an entire sleep/wake cycle.

Since WHOOP measures the metrics included within the WHOOP Recovery Score (i.e. Heart Rate Variability, Resting Heart Rate, Respiratory Rate) and your Health Monitor metrics during sleep, this sleep-to-sleep physiological day (also known as a cycle) ensures WHOOP provides the best possible Recovery insights.

Your Recovery score is tied to your sleep. You get one Recovery score per sleep rather than one per calendar day. This is a key difference between a Sleep and a Nap activity on WHOOP. A Sleep generates your Recovery score whereas a Nap reduces your sleep debt, but does not come with a Recovery score and does not begin a new cycle.

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Above is a high-level view of an entire cycle (you can access this view by tilting your screen sideways while using the WHOOP app on your phone). 

When this member falls asleep at 9:36pm, their cycle begins, and continues until they fall asleep the following night (the blue dotted line indicates when they fell asleep, ending their cycle). This encompasses their full day, and gives them the most accurate Recovery and Strain data available.


Why do I see a date range after midnight?

This is because WHOOP uses 12 am as a changeover point to separate one calendar day to the next within the app, even if you have not yet recorded a sleep activity. Sleep schedules vary from person to person. While one person’s single-day cycle may last for 20 hours (the amount of time between the start of one Sleep activity and the start of another Sleep activity), someone else may go 36 hours between two sleep activities (an ultra marathon runner, for example). 

The changeover ensures that a member’s data matches as closely to a calendar day schedule as possible. Yet, because a new data set cannot begin without a Sleep activity, the WHOOP mobile app may present a member’s current data in a variety of formats, such as Yesterday’s date through Today (ex: APR 12 - Today).

For instance, consider the following scenario where the date range provided at the top of this screenshot (APR 12 - Today). This indicates a member who has opened their whoop app after 12 AM/Midnight on Tuesday, April 14, but has not yet recorded a new Sleep activity for Tuesday night. 

In other words, they last slept from Monday April 12 - Tuesday April 13, creating a dataset for April 13. Yet the current calendar date in their timezone is April 14, but they have not yet recorded a sleep activity between Tuesday April 13 - Wednesday April 14. So, WHOOP presents the current data set as a range between their previous day and their current day. By manually entering a sleep activity, the app will recalculate the new physiological day for Wednesday. 

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This second example represents a retrospective view of the same date range where the member never recorded a sleep activity for April 14. 

Again, since a sleep activity marks the beginning of a new physiological day, there was no new cycle or recovery created for April 13. Instead, the day cycle from April 12 changed to a range between the two calendar dates (April 12 - April 13), and any additional Strain or calories that accumulated after 12 AM on April 14 was added to the appropriate cycle.

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What if I’ve woken up and don’t have a detected sleep and/or no recovery score?

This can happen for a variety of reasons:

  • WHOOP failed to auto-detect your sleep

  • WHOOP recorded your sleep as a nap

  • WHOOP split your sleep into a sleep event + nap (also known as a split sleep)

  • An overlapping activity from the previous cycle

  • Your app reports WHOOP is “catching-up” or there is no recorded data


WHOOP failed to auto-detect your sleep

This is especially common when you’re first starting your WHOOP journey. WHOOP can take up to 30 days to align with your unique physiology, and it’s crucial in the early days of your membership to manually add missing sleeps. This will help our algorithm recognize your unique sleep patterns. Over time the device will begin to pick up what your heart rate looks like during sleep. 

If you're a tenured member and experience this, many times the cause is aberrations in your heart rate during sleep (can be due to external factors such as stress or alcohol). There are two ways to add tour sleep. For the first, you can manually add your sleep activity by using the Action Item icon on your overview screen. 

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For the second, you can manually add your sleep in the Activities section on the overview screen. 

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As more of these are manually entered, WHOOP will continue to learn and miss these less and less. 

WHOOP recorded your sleep as a nap

WHOOP has accounted for this issue, and there is an in-app fix for this. If your cycle defining sleep has been incorrectly logged as a nap, you can correct this by using the following steps:

  1. Tap the nap from your WHOOP overview screen

2. Tap the pencil icon (Edit) on the right center of the page

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3. Tap Convert to Sleep

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4. Tap CONVERT on the confirmation screen

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Your cycle should now process, giving you all of your Sleep and Recovery data for the current cycle. If this does not fix the issue, please send a message to Membership Services and we’ll be happy to help. 


WHOOP split your sleep into a sleep event + nap (also known as a split sleep)

Some members may occasionally see a Sleep event followed by a nap that are two pieces of the same sleep. It's important to note that WHOOP's sleep algorithm is always working as it receives data, and can take a few minutes at the end of a sleep event for us to recognize the sleep is over and finish processing it, much like the auto-detection of workouts.  In cases where our system hasn't caught up, you may see a second sleep activity.

If you give the system a few minutes, and allow WHOOP to continue its auto-detection process without manually editing the data, it should merge the two sleeps together. If you are awake for a period of longer than 50 minutes, your sleep event will split into a sleep and a nap. 

In rare cases when it does not merge the two events, this is an easy fix. You can delete the nap (be sure to note the end time), and edit the sleep to include the entire sleep window.  Your Recovery will now recalculate and your complete sleep metrics will process. 

An overlapping activity from the previous cycle

If you happen to forget to stop a Strain Coach activity from a previous cycle, your sleep will not process as there is now an overlapping activity from the previous cycle. If you attempt to manually add your sleep, you will likely run into the following error message:

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To resolve this, you can navigate back to the previous day within the app and edit (or delete) the activity with the proper time bounds. Once you’ve done this you can manually add your sleep and all of your Recovery and Strain metrics will process for the current day. 


Your app reports WHOOP is “catching-up” or there is no recorded data

The first thing to check here is that your data is caught up. Pull down on the overview screen, you should see a banner that let's you know that you're data is all caught up. 

If not caught up, the banner will indicate that your data is catching up. Make sure to keep the app open in the background of your phone and it will upload and process your sleep. If the upload is current and you still don't see a sleep, that can be manually added by clicking the stick figure in the middle right of your overview screen.

If you’ve tried the above steps and your sleep still won’t process, it’s best to flip your phone screen horizontally and ensure that HR data is present. If you notice any gaps in your HR data, or there is none and you have been wearing your device, please write in to membership services so we can get it taken care of.

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