What I Learned Tracking My Sleep Every Night for a Year

There are dozens of devices that promise to accurately track your sleep, making sleep insights accessible outside of a sleep lab. But how useful is this data for the average person? With so much to juggle in our health, sleep tracking might just feel like another distraction.

After tracking my z's for an entire year, I do think there are practical benefits to keeping track of your sleep data. Here's what I learned.

My favorite sleep tracker

The device I use to track my sleep is the Garmin Forerunner 965. This watch, like most newer Garmins, tracks your sleep duration, sleep stages, nightly movement, nightly stress, heart rate variability and respiration rate. The device synthesizes all the factors into a nightly sleep score provided in a handy morning report. 

The nightly sleep score is an easy metric to track, and it's the one I look at the most because it provides a good snapshot of how you slept on any given night. However, you can really dive into the data by looking at your sleep stages or stress levels, too, if you want. 

Garmin Forerunner 965 $527 at Best Buy

There are plenty of other devices, such as the Whoop Band, Oura Ring and Apple Watches, that also track your sleep. 

Is sleep tracking actually useful?

The biggest thing I've learned is that sleep data on an individual night isn't all that valuable. It's pretty easy to know how well you slept any given morning, just based on how you're feeling. I know that if I wake up several times at night, my sleep score will be low, and my energy level will be, too. 

The thing to pay attention to is trends in your sleep data. Does the data say you've been getting poor sleep for several nights in a row? If yes, check in with yourself on how you're feeling. Over the past year, I've had two colds -- and both times, a dip in my sleep data was the early warning sign that symptoms were coming and it was time to slow down.

Also, a trend in your sleep data could mean that a behavior change you haven't noticed is impacting your sleep, like additional screen time before bed or caffeine later in the day. 

Top insights from a year's worth of sleep data

One thing I love about the Garmin Connect app is that it keeps a ton of your health metrics easily accessible. I could easily review my entire year of sleep, with weekly averages and the ability to check individual nights.

By looking back at my data, and taking notes throughout the year, these are the top six things I learned from my sleep data.

1. Sleep directly correlates to my athletic performance

This is a pretty obvious point, but good sleep really does lead to better physical performance. I have heard this for years and never doubted its validity, but seeing it in the data is clarifying. 

I ran my first-ever marathon in 2024, and I wasn't in very good cardiovascular condition before starting to train. I quickly discovered that a good sleep score from the night before led to better, more productive training runs. 

Before the big race, my training plan called for a 20-mile run to get my mind and body used to running that far. The night before I planned to do this run, I happened to have my highest-ever recorded sleep score, 95 out of 100, and I cannot remember a time when I felt better physically. 

The night before the race, I didn't get good sleep because I had to wake up at 3:30 a.m. to catch the shuttle to the starting line, plus, the anticipatory stress made falling asleep challenging. Despite a poor night's sleep, I was able to finish just under my goal time, but my body didn't feel as good. 

My specific sleep tracker, the Garmin Forerunner 965, also uses sleep data to help track your recovery after exercise. I learned early on that the recovery time metric was not a number I could ignore. If I had a hard run and then got a poor night's sleep afterward, the next day, I would have a hard time exercising. 

2. Consistent exercise improves my sleep

There was a roughly six-week window early this year when I needed to take a break from running due to plantar fasciitis in my right foot. During those six weeks, I had more trouble with my sleep than I had in all previous months, and my sleep scores trended down. Once my foot recovered and I started running regularly again, my sleep improved almost immediately. 

"There's strong evidence that regular exercise can improve sleep quality," Annie Miller, the founder of DC Metro Sleep and Psychotherapy, told me. "Physical activity helps regulate your circadian rhythm, reduces stress and increases time spent in deep sleep -- the most physically restorative stage. It's not uncommon for people to notice better sleep during periods of consistent training and, conversely, more disrupted sleep when movement is limited."  

I found this to be unambiguously true in my case, but only you can determine if exercise improves your own sleep or not. My colleague Aly Lopez tracked her sleep with increased swimming and it didn't improve. 

3. Consistency is key

The Garmin watch I wear had me set my target sleeping hours during the initial setup and it automatically enters sleep mode, which blocks notifications and the watch face from lighting up. I set my sleeping hours from 10 p.m. to 6 a.m. and stick to that pretty closely. 

On nights when I fall asleep and wake up later, although I achieve the same hours of sleep, my overall sleep score and time spent in deep sleep are typically lower.

When I am able to get to sleep at the same time and wake up at the same time for many consecutive days, my sleep score remains at a steady high. 

4. Alcohol is shockingly bad for my rest

I generally didn't drink much alcohol, even before I started tracking my sleep every night, but now that I've seen what even small amounts of it do to my sleep, I drink even less. 

Even one or two regular beers around 5% ABV can lower my sleep score by up to 20 points, and I get lower amounts of REM and deep sleep. The lowest sleep score I had the entire year I tracked was 35 out of 100 after a night at a bar where I had several drinks. 

"Even small amounts of alcohol can significantly disrupt sleep," Miller says. "While it may help you fall asleep faster, alcohol suppresses REM sleep -- the stage of sleep linked to dreaming, emotional processing, and memory consolidation. It also increases the chances of waking up in the second half of the night, leading to more fragmented and less restorative sleep overall." 

Just looking at the data from that specific night of sleep, I woke up in the middle of night and couldn't go back to sleep which was a huge factor in my poor sleeping. Plus, on top of that, I got a mere eight minutes of REM sleep.  

I'd be curious to see this data from my younger years, when I bounced back from a few drinks more easily -- but now, in my mid-thirties, it's clear: alcohol and quality sleep don't mix. And as Miller says, "even just a drink or two can show up clearly in sleep data."

5. My sleep quality is best at home

The few times I traveled this year, I always slept worse. My average sleep score across the entire year of tracking was 79 out of 100, and when I took a trip, my average for those nights was noticeable lower.

In June 2024, I took a week-long trip to Venice Beach, and my average score dropped to 71. When I went to Oregon for the holidays, my average score for that week also dropped to 71. Once I got home, my scores rebounded back into the mid- to low-80s. 

And even on shorter trips that only lasted a night or two, my scores were lower. Part of it is having a great mattress I love, but it's also the comfort of being in my own home.

Stress is a big factor when it comes to sleep issues, and being in new places, no matter how nice they are, can increase stress levels and cause worse sleep. According to Miller, "Our brains are incredibly responsive to our environment, and for many people, home is associated with comfort, safety, and routine -- all key ingredients for good sleep. So it's no surprise that sleep often takes a hit in a new place." 

I definitely feel very comfortable in my own home and I make sure to not have any electronics in my bedroom. I try to avoid screen time before bed and I usually read for 20-30 minutes before.

The data is pretty clear in my case, but Miller states that's not true for everyone. "I've also worked with people who sleep better outside their homes, especially if their bedroom has become associated with insomnia, stress, or disrupted sleep. It really depends on the emotional and behavioral associations your brain has built around where you sleep," she says.

6. I sleep better in winter

I also noticed I sleep better when the house is colder. I live in Reno, Nevada, where winters are cold and summers can hit the high 90s or low 100s. In summer 2024, my A/C was out for a bit -- and it definitely affected my sleep. This window of summer without AC was easily the worst six weeks of sleep I had in the entire year. 

Even sleeping on one of the best cooling mattresses on the market, it was difficult to fall asleep and stay asleep and I tossed and turned a lot more trying to get relief. 

In the winter, I usually set the thermostat between 60 and 62 degrees and bundle up to save on my electric bill. Under heavy blankets, I usually fall asleep in one comfortable position and stay in it the entire night, leaving me feeling more refreshed in the morning.

There's a lot of evidence for a colder room being beneficial to sleep quality and there are a lot of products like the Bedjet and the Eight Sleep Pod system that are designed to better regulate your sleeping temperature. 

Bottom line

Wearing my sleep tracker every night for a year gave me some great insights. I made small changes to my habits and nightly routine that ended up improving both my sleep and overall health.

For some people, though, all this sleep data could be statistical noise that doesn't do anything for them and could actually be bad for them. Studies suggest people can develop disordered sleep because they are fixated on sleep optimization, also called orthosomnia. If you try using a sleep tracker and are anxious about your metrics, I would stop using it.

"These devices aren't perfect at measuring sleep stages, and for some people, tracking can lead to over-fixation or anxiety about sleep -- which can actually make sleep more difficult," says Miller. "The goal is to use the data as a gentle guide, not a strict scorecard. If it helps you make positive changes without adding pressure, that's when it becomes truly helpful."

For me, I was able to get a lot out of sleep tracking, and it could be a useful tool for people looking to improve their health or train for something like a foot race.