Please add Sleep Debt metrix

Do you really need an app to tell you if you feel tired to get an early night? That is 'debt' rephrased and saves you $85 a year right there ;)

ha ha - no, but a running 14 day sleep debt is something most people don't consider. Most will only think within 3 days.
Additionally, the algorithm worked out your nature sleep need, which was very interesting.

I’d love to have this as well. I just tried the RISE app as well, and liked it, but not enough to pay for it.

Reasons I’d love to have it:

1. When marathon training, it’s hard to distinguish “tired” from “sleepy.” Sometimes I don’t notice sleep debt accumulating because I’m already physically tired from training and it sort of masks the sleep-related fatigue.

2. I’m really interested in how sleep debt affects training. I had a miserable training cycle for my last marathon and couldn’t even finish most of my long runs (15-20 miles). Late in the training cycle I realized it was linked to sleep… my long runs just happened to be scheduled at times that my kids had had a few rough nights in a row, so I’d been building up a little sleep debt. Having some actual tracking of sleep debt would be SO helpful for adjusting pacing and expectations going into certain workouts.

+1 to this. I just got the forerunner 955 and the sleep tracking + body battery is great but the sleep debt would be killer. I'm about to pay for Rise, but I'd imagine with all the health data my Garmin has it could do a really good job of taking the body battery feature and wrapping in things like sleep debt to give me target sleep times plus energy windows based on my circadian rhythm etc.

A sleep debt tracker would be really easy to implement in Garmin Connect and it would be far more useful than sleep stages or even, arguably, sleep scores This is because a wearable can track time asleep far more accurately than it can track sleep stages / quality and because the users have much more control over time asleep than anything else. If I am running up a sleep debt, I can go to bed early but if I am not getting as much REM sleep as I would like, I can...?

Would definitely love to see this added as an update to the app.

You already have body battery, now HRV status, stress score. What would sleep debt give you that these don't?

All of those are influenced by your activities and by other health factors, and are largely about the current day (except the lingering effect of the prior day’s battery).

Sleep deficit is more narrow, and therefor more useful for simply assessing the cumulative effect of sleep. Sleep deficit calculations tend to look at a rolling window of 7 days or more, so they can help you notice a situation where you’ve had a few good nights of sleep in a row and wake up with a full body battery, but are still in a sleep deficit from earlier and might have difficulty with alertness and energy in the afternoon. This is a very common scenario for me, as a parent — most nights I sleep reasonably well, but when my kids sabotage a night the effects linger a lot longer than my watch currently recognizes.

Sleep debt and body battery will definitely be correlated but they are far from being the same thing so, given how easy the implementation would be, there is definitely a benefit to presenting them as separate metrics. As an example, my body battery will rise if I am in a relaxed state of mind while quietly reading a book in the evening, but this will do absoluetely nothing to reduce my sleep debt. My brain might be relaxed, but it's still awake - and I'll still feel like a wreck in the morning if I don't put that book down and go to sleep for 8 hours.

Several studies have shown that cumulative sleep debt is the most important metric for people to keep an eye on as far as sleep health is concerned, and it's far more objective and easier to understand than proprietary sleep scores that focus on only one night at a time.

it would be a nice feature from Garmin but I'm not sure they would be willing to overcomplicate stats GCM already provides.
In the meantime you can try SleepAsAndroid, I've bought it ages ago so don't remember the pricing, but it was definitely less and I think there is a free version of it as well. It has sleep debt and other fun metrics which you can analyse over time. I'm using it on my old phone still. Before I got Fenix it was useful to correct my sleep time on Garmin, right now Garmin and SleepAsAndroid seems to agree the most to time