Why your sleep score sucks
The cheat codes for what your wearable is measuring
My best childhood friend has two daughters in their early 20s, and I recently learned they both wear the RingConn Smart Ring to track their sleep and health metrics. Even cooler, these girls have gamified their sleep scores and compete every morning for the highest score.
This generation seems dramatically more health-conscious than my Gen X counterparts ever were. Pretty sure we spent most of our early 20s standing in a field drinking canned beer, saying things like “I will sleep when I’m dead,” but I digress.
As someone working in circadian and lifestyle medicine, and more importantly, in my quest to become the coolest auntie, I wanted to map out the fastest ways to hack a sleep score beyond just going to bed earlier.
So here are the cheat codes for all the other cooler-than-me 20-somethings wearing smart rings and optimizing their REM sleep.
I even wrote a downloadable one-pager for you at the end. May the best sleeper win.
Let’s start with what data the ring is actually collecting
The sleep score pulls from five data streams: sleep stages (light, deep, REM), heart rate variability (HRV), blood oxygen saturation (SpO2), skin temperature, and something most people scroll past entirely: social jetlag, the difference in your sleep timing between weekdays and weekends [18,19].
A smartwatch or ring tracks your sleep using two main sensors: an accelerometer that detects movement and an optical heart rate sensor that measures heart rate and heart rate variability.
It then uses algorithms to infer which sleep stage you're likely in based on those movement and heart rate patterns, making an educated guess about your brain state from signals recorded at your wrist or finger.
Heart Rate Variability (HRV) is the beat-to-beat variation in your heart rate during sleep. High variability generally reflects a recovered, adaptable nervous system. Low variability means something kept it activated overnight: stress, alcohol, a late meal, schedule inconsistency. Your ring uses this as a proxy for actual recovery, not just time asleep.
Skin temperature is a newer feature in consumer wearables but physiologically important, as your core temperature needs to drop by around 3-5°F to initiate deep sleep. The ring tracks peripheral thermal changes, and an elevated overnight skin temp reading could mean something got in the way.
Social jetlag is where it gets interesting. RingConn now directly scores sleep rhythm regularity, flagging more than 1 hour of difference between your weekday and weekend sleep midpoints as disrupted biological timing [20].
By contrast, a polysomnogram, which you would have during a proper sleep study, directly measures brain electrical activity using scalp electrodes (EEG), along with eye movements, muscle tone, breathing, and oxygen levels. This gives a complete, unambiguous picture of exactly what your brain and body are doing at every moment of the night.
Some quick biology levers to pull
Deep Sleep
Deep sleep is your body’s overnight maintenance window during which tissue repair, growth hormone secretion, immune consolidation, and memory processing occur. It’s also the stage most sensitive to thermal interference, and three things reliably suppress it:
evening alcohol
late eating, and
a warm room.
Alcohol is worth understanding specifically because it feels like a sleep aid.
A 2024 systematic review and meta-analysis confirmed that even low doses reduce REM sleep, with larger doses producing progressive disruption across sleep architecture. Alcohol is not an appropriate sleep strategy at any dose [5] because it works like this: alcohol’s sedative effect front-loads heavier sleep, but as it metabolizes into acetaldehyde mid-night, your nervous system rebounds.
HRV drops, skin temperature rises, REM in the second half of the night gets suppressed. The ring sees all of it. The sleep data is one chapter of a longer story and I’ve written the full metabolic case against alcohol in Why You Should Never Drink Alcohol.
Late eating disrupts the same thermal process through a different pathway.
Digestion raises core temperature through diet-induced thermogenesis, and a 2024 scoping review found that this thermal elevation can persist beyond your tummy emptying when the meal-to-bedtime window is short. The result is delayed sleep onset and suppression of that coveted deep sleep [2].
Beyond temperature, late eating raises blood glucose and activates daytime hormones, specifically insulin, cortisol, and digestive enzymes, at the exact moment your body is trying to switch into its night-mode hormonal program. Late eating biologically signals that the day is still ongoing.
Room temperature is the simplest lever most people never pull.
The target range is 60–67°F. Your body is actively trying to lose heat to reach deep sleep, and a warm room works against that physiology all night, not just at onset.
Heart rate variability and sleep regularity
A study of over 60k UK participants across the span of 8 years found that sleep regularity was a stronger predictor of all-cause mortality than sleep duration. Higher regularity in sleep-wake times was associated with up to 57% lower cardiometabolic mortality risk [17].
Your master clock, the suprachiasmatic nucleus, (SCN) in the hypothalamus coordinates with the outside environment using light (or lack of), and then tells your cells and organs (the peripheral clocks) the time to sync to. This happens through myriad ways, two important ways being hormones and the nervous system.
The SCN uses your wake time as a calibration signal because we are biologically positioned to awake, presumably, when the sun starts showing its face. A consistent wake time triggers a reliable cortisol peak, which synchronizes peripheral clocks throughout the body: liver, gut, immune cells, pancreas, lungs, etc. Keep shifting by two hours and eventually every downstream timing signal drifts away from the central timing mechanism.
The cortisol awakening response (CAR) is a surge in cortisol in the 30–45 minutes after waking, and a key marker in metabolic medicine [15]. A blunted or absent CAR reflects dysregulation and has been associated with obesity, insulin resistance, and type 2 diabetes. A consistent wake time is anchoring, and along with morning sunlight, signals the central clock precisely where it is in the 24-hour cycle. Overnight, your HRV responds accordingly.
Social jetlag
Let’s say during the week you’re up at 7am, but Saturday you sleep until 10. That three-hour shift actually moves your biological clock. By Sunday night your hormones and functions could be running two to three hours behind the clock on the wall and you end up lying awake.
A 2024 meta-analysis found that social jetlag was significantly associated with components of metabolic syndrome, specifically elevated fasting glucose and raised blood pressure [8]. Then in 2025, NHANES (the U.S. National Health and Nutrition Examination Survey) estimated that about 69% of adults carry at least one hour of social jetlag, with associations extending to obesity, type 2 diabetes, and cardiovascular disease [14].
Your ring is scoring this because the downstream metabolic consequences are real, and in a large portion of the population.
Screens at night aren’t the problem you think they are
Most people understand that screens before bed are disruptive. The reason, though, is deeper than we think.
We’ve long thought of melatonin as the sleep hormone. That framing is correct but also incomplete. Melatonin rises at night precisely when cells need protection from oxidative stress. It is made in two different areas of our body: the pineal gland and the mitochondria.
Pineal melatonin is released into circulation at night as a hormonal time signal (“it’s dark outside”), and mitochondrial melatonin is produced locally inside cells and functions more like a protective molecule.
When our internal rhythms are intact, antioxidant defenses rise when oxidative stress has risen. The body anticipates the oxidative stress from daytime activity and sends in missile defenses at night to fight the good fight. When the internal rhythms are disrupted, antioxidant defenses essentially die, but that daily reactive oxygen species continues to be made [9].
Even 10 lux of blue-spectrum light, well below the typical brightness of a phone screen in a dark room, can suppress melatonin by over 50%. A phone in a dark room from 10pm to midnight is removing a mitochondrial stabilizer during its peak activity window, every night.
Block melatonin with screen light and you remove that protection at exactly the wrong moment. This becomes much bigger than a sleep issue, venturing into an oxidative stress problem.
The biological signal your body needs to initiate melatonin production is not darkness. It is the drop in light intensity. Dim light melatonin onset (DLMO) is the clinical marker for when this begins, typically 2–3 hours before habitual sleep onset under normal light conditions [12].
Bright evening environments push DLMO later and sleep onset is shifted later. The ring captures the consequence in shortened REM and compressed early deep sleep.
Why this matters beyond the score
It’s a lot of fun to gamify sleep scores but here is what I actually care about for you: the biological system your ring is measuring your sleep against governs considerably more than recovery. We are now in circadian biology territory. I know, cool. Right?
In 2016 a group of scientists conducted a controlled study where participants were put into a very controlled lab environment. They were tested for their daytime-ness or nighttime-ness (whether they were a morning lark or a night owl + their DLMO we talked about earlier). Each participant was restricted to a specific activity window the either aligned or misaligned with their internal clocks.
Zero changes to their diet, how long they slept, or what exercise they did. For the misaligned group, within days of the study starting, their lab markers showed an increase in systolic blood pressure, increased inflammatory markers, and lowered glucose tolerance [10,11].
In October 2025, the American Heart Association published a scientific statement linking internal timing disruption to obesity, type 2 diabetes, hypertension, and cardiovascular disease, and named behavioral timing optimization as a disease prevention strategy [1].
That same year, a paper in Current Issues in Molecular Biology confirmed that irregular sleep-wake cycles and mistimed eating are now recognized as independent cardiovascular risk factors that accumulate years before anything surfaces in a standard lab panel [13].
The data on your finger at night is telling you something your blood work may not show for another decade, which is, to me, a tremendous opportunity to start locking in a great quality of longer life ahead. If you are interested in learning about your smart ring hypnogram and why restorative sleep is THE game changer, read my next article on Restorative Sleep Stages.
P.S. I built a free cheat sheet that details all the hacks you can implement to move your sleep score, and you can download that here:
Some additional reading if you want to nerd out further:
I wrote recently about why biological timing is likely to become one of medicine’s most consequential levers, in Why timing may become medicine’s next major frontier.
The sleep data your ring is generating nightly is exactly the early signal that makes that case. For the full mechanistic picture, read Circadian timing as a systems-level regulator of chronic disease; that is the paper I’ve spent the better part of this year building, and this article is its clinical summary.
The gut runs on its own biological clock and is acutely sensitive to the same timing disruptions affecting your sleep score. Gut health and chronic disease (Part I) gives a lot more detail on that connection if you want to follow the thread.
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If this was useful, here’s where to go next:
→ You’re navigating chronic illness and want a clear roadmap: go here
→ You lead a clinic and want to bring this education to your patients: grab the sample curriculum here
→ You run a retreat and want to add science-backed depth to your program: go here
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References
1. American Heart Association. (2025). Role of circadian health in cardiometabolic health and disease risk: A scientific statement from the American Heart Association. Circulation. https://doi.org/10.1161/CIR.0000000000001388
2. Bagues, A., et al. (2024). Chrono-nutrition and sleep: Lessons from the temporal feature of eating patterns in human studies. A 2024 systematic scoping review. Sleep Medicine Reviews. https://doi.org/10.1016/j.smrv.2024.101951
3. Baranowska-Bosiacka, I., et al. (2025). Melatonin and lipid peroxidation: Antioxidant shield and therapeutic potential. Frontiers in Bioscience (Landmark Edition), 30(12). https://doi.org/10.31083/FBL45321
4. Gabriel, B. M., Altıntaş, A., Smith, J. A. B., Sardon-Puig, L., Zhang, X., Basse, A. L., Laker, R. C., Gao, H., Liu, Z., Dollet, L., Treebak, J. T., Zorzano, A., Huo, Z., Rydén, M., Lanner, J. T., Esser, K. A., Barrès, R., Pillon, N. J., Krook, A., & Zierath, J. R. (2021). Disrupted circadian oscillations in type 2 diabetes are linked to altered rhythmic mitochondrial metabolism in skeletal muscle. Science Advances, 7(43), eabi9654. https://doi.org/10.1126/sciadv.abi9654
5. Gardiner, C., Weakley, J., Burke, L. M., et al. (2024). The effect of alcohol on subsequent sleep in healthy adults: A systematic review and meta-analysis. Sleep Medicine Reviews. https://doi.org/10.1016/j.smrv.2024.101951
6. Lei, Y., Xu, Y., Huang, J., Huang, Y., Tu, Z., Xu, Y., & Liu, Y. (2024). The potential influence of melatonin on mitochondrial quality control: A review. Frontiers in Pharmacology, 14, 1332567. https://doi.org/10.3389/fphar.2023.1332567
7. Lempesis, I. G. (2025). Illuminating the metabolic effects of circadian misalignment. Nature Reviews Endocrinology, 21(3), 202. https://doi.org/10.1038/s41574-024-01085-6
8. Lin, M. Y., Kang, Y. N., Apriliyasari, R. W., & Tsai, P. S. (2024). Association between social jetlag and components of metabolic syndrome: A systematic review and meta-analysis. Journal of Nursing Research, 32(5), e354. https://doi.org/10.1097/jnr.0000000000000628
9. Mezhnina, V., Ebeigbe, O. P., Poe, A., & Kondratov, R. V. (2022). Circadian control of mitochondria in reactive oxygen species homeostasis. Antioxidants & Redox Signaling, 37(10–12), 647–663. https://doi.org/10.1089/ars.2021.0274
10. Morris, C. J., Purvis, T. E., Hu, K., & Scheer, F. A. J. L. (2016). Circadian misalignment increases cardiovascular disease risk factors in humans. Proceedings of the National Academy of Sciences, 113(10), E1402–E1411. https://doi.org/10.1073/pnas.1516953113
11. Morris, C. J., Purvis, T. E., Hu, K., & Scheer, F. A. J. L. (2017). Circadian misalignment increases C-reactive protein and blood pressure in chronic shift workers. Journal of Biological Rhythms, 32(2), 154–164. https://doi.org/10.1177/0748730417697537
12. Murray, J. M., Stone, J. E., Abbott, S. M., et al. (2025). A modified at-home methodology for measuring dim light melatonin onset timing in healthy adults. Chronobiology International, 42(5), 653–663. https://doi.org/10.1080/07420528.2025.2500404
13. Nuszkiewicz, J., Rzepka, W., Markiel, J., et al. (2025). Circadian rhythm disruptions and cardiovascular disease risk: The special role of melatonin. Current Issues in Molecular Biology, 47(8), 664. https://doi.org/10.3390/cimb47080664
14. Santos, P. M., et al. (2025). Social jetlag, sleep, and metabolic syndrome in adults: Insights of circadian misalignment from NHANES 2017–2020. Sleep Science and Practice. https://doi.org/10.1186/s41606-025-00158-3
15. Stalder, T., Oster, H., Abelson, J. L., Huthsteiner, K., Klucken, T., & Clow, A. (2025). The cortisol awakening response: Regulation and functional significance. Endocrine Reviews, 46(1), 43–59. https://doi.org/10.1210/endrev/bnae024
16. van Moorsel, D., Hansen, J., Havekes, B., Scheer, F. A. J. L., Jörgensen, J. A., Hoeks, J., Schrauwen-Hinderling, V. B., Duez, H., Lefebvre, P., Schaper, N. C., & Schrauwen, P. (2020). Human skeletal muscle exhibits a day–night rhythm in mitochondrial oxidative capacity. Proceedings of the National Academy of Sciences, 117(15), 8758–8764. https://doi.org/10.1073/pnas.1916823117
17. Windred, D. P., Burns, A. C., Lane, J. M., Saxena, R., Rutter, M. K., Cain, S. W., & Phillips, A. J. K. (2024). Sleep regularity is a stronger predictor of mortality risk than sleep duration: A prospective cohort study. Sleep, 47(1), zsad253. https://doi.org/10.1093/sleep/zsad253
18. RingConn. (2025a). Sleep pattern analysis: Smart ring sleep tracking. https://ringconn.com/pages/how-ringconn-helps-with-sleep-pattern
19. RingConn. (2025b). Your RingConn scores explained: Master your health. https://ringconn.com/blogs/news/guide-ringconn-health-scores
20. RingConn. (2025c). Unlock better sleep with RingConn Gen 2 smart ring. https://ringconn.com/blogs/news/unlock-better-sleep-with-ringconn-gen-2-smart-ring
My RingConn gives me a sleep score and sleep efficiency.
You neglected an important demographic: baby boomers wearing RingConn rings and acting like elite athletes.
Some of us have gone from “sleep when you’re dead” to protecting our sleep score and HRVs like it determines selection for a national team.