The year in review

I'm about to take a look at an entire year of WHOOP data: September 2025 to September 2026. This past year I took part in 524 training sessions, logging about 378 hours of activity. Throughout all this data collection, only one thing really mattered: my sleep. In this self-analysis, I'll take a look at how I slept, what that did to my recovery, and how much I actually did.

Sleep

Bedtime and recovery

From taking a look at my sleep data, the most important factor in how much I actually recovered was when I went to bed. The later I went to bed, the less I recovered. The later I woke up, the more I recovered, but not enough to make up for going to bed late.

Bedtime correlates -0.46 with how much I actually sleep; wake time only 0.39. Sleeping in barely makes up for going to bed late. 208 of 366 nights started after 2am, and those nights average 52% recovery. Nights before midnight average 76%, that's a difference of 24 percentage points. Although it should be noted that my bed times were consistently later than the average person, and the number of data points available for bedtimes before midnight is much smaller than the number of data points for bedtimes after 2am. Even still, the trend is clear: sleeping earlier is better for recovery.

Deep sleep and REM

On short nights the body protects deep sleep first and cuts REM.

From this chart we can see that regardless of sleep, deep sleep stays relatively constant, while REM sleep is the one that gets sacrificed the most, growing from 52 minutes on the shortest nights to 149 minutes on the longest, a nearly 3x increase.

The weekly pattern

The week has a shape too.

My sleep schedule is clearly a mess, but I knew this before I bought a WHOOP. It was just confirmed by the data. I'm not gonna write some spiel about how I should sleep more, or that I should sleep earlier, because I already know that. The real pattern here is that the weekends lead to dramatically worse recovery on Mondays, while the weekends themselves are not that bad.

This is pretty easily explainable, as things just happen on the weekends that lead to later bedtimes, and then the next day I have to wake up early for work. What isn't excusable is how my week is also just consistently bad as well.

The trend

The trend ran the wrong way all year, peaking in December, but generally just very late sleep times. We'll see how the next 365 days go, now that this is visualized in my face. I expect a huge improvement, when we revisit this.

Recovery

Before diving into the data, we'd have to define what "recovery" means. Recovery is a WHOOP metric that takes into account your heart rate variability, resting heart rate, and sleep performance to give you a score from 0-100% on how recovered you are. Obviously, this is merely a metric, and your actual recovery is dictated by how you actually felt, but this provided a good baseline to look at the data.

What predicts recovery

HRV and sleep performance do a lot of the heavy lifting when it comes to recovery; resting heart rate and REM duration matter too. Something that I thought would be more important, sleep efficiency and sleep consistency, are actually not that important. It turns out that you can sleep efficiently, and on a consistent schedule, but if the duration is short, it has no positive effect on recovery.

Resting heart rate barely moved over the year — 49.8 to 50.3 comparing the first 90 days to the last — even as HRV rose about 11 points over the same stretch. Real aerobic adaptation on one metric, not a transformation on the other. I have personal insights into why that is, and will be making changes to my daily routine to mitigate that lack of RHR improvement.

What doesn't hold up

Before turning any of this into a goal, worth showing what doesn't hold up: The WHOOP Journal feature lets you register a lot of different behaviors and see how they correlate with recovery. A few of those false positive correlations are worth calling out, because they look like they should matter and don't.

The illness signal

There is an interesting signal in the data that is not related to sleep or training load, but has a huge effect on recovery. It's WHOOP's early-illness signal, which is when skin temperature jumps more than half a degree above its own two-week baseline. When this happens recovery craters to 40.3%, against a 58.2% baseline. I'm not sure what causes this, but it is worth noting that this is a different failure mode than anything sleep-driven.

Mexico City

Something interesting I noticed when I went to visit my boy in Mexico City was that my recovery was getting absolutely fried. I was getting less sleep, the sleep was horrible, and I was still training hard. The week between February 15 and 21 was the worst week of the entire year by a wide margin: 18.3% average recovery against a 59.0% baseline for the year. I had a classic case of adjusting to altitude, and it was hard and clearly the data showed that I was struggling. Over the week, my RHR was up 13bpm, HRV down 44ms, and blood oxygen down 2.2 points. The lack of sleep, and long nights did me no favours either, but generally, I would average around 32% recovery with the same sleep stats. Anyways, the vacation was lit, would do it again.

Even against February's own average (which was my worst month of the year), this trip was particularly brutal on every metric.

Activity levels

So, the past two sections were looking at things I could have improved a lot on; however, not all was bad. One area I personally felt I was performing well in was the level of activity I achieved throughout the year.

What I did

I was consistently hitting the gym, walking frequently, and playing soccer, all things I wanted to do in my goals from summer 2024 post. I have a good feeling that the next version of this chart is going to have a lot more activity.

Training load went up over the year while recovery went down — monthly sessions grew from 35 in September 2025 to 80 in August 2026, hours from 25 to 56. Training load grew faster than sleep could support it.

Hard-training streaks

The chart above says that if I train hard (14+ strain) three days in a row, my recovery craters on day three. I have a hunch this is not due to the fact that my strain is accumulating, but rather I do not give myself adequate rest when it comes to actually dealing with accumulating fatigue.

Appendix

If I think of any other charts I'll add them here as I revisit this topic sometime.

Recovery by month