# Resting heart rate: the canary in the coal mine

In 1,200 nights of one client's data, every 1 bpm drop in RHR = ~6 more minutes of sleep.



## Takeaways

- Lower RHR → longer sleep.

- Get fitter and down-regulate before bed.

- Watch alcohol's effect on your night-time HR.



Galpin's team found in a long ring dataset that each one-beat drop in resting heart rate came with six more minutes of sleep. Two levers move it: cardiovascular fitness (endurance training lowers RHR ~5 bpm on average) and down-regulation before bed (a calmer nervous system going into bed → longer sleep).

For a busy person it became the one thing to pay attention to: do whatever it takes to keep heart rate low going into bed. Alcohol is the fastest way to push it the wrong way — even 'low' intake cuts sleep HRV by ~9%.

SleepShred computes the same correlation on your own data once you have enough nights with resting HR (from Apple Health or manual entry).



## Sources

- Effects of exercise on the resting heart rate: a systematic review and meta-analysis of interventional studies (Reimers AK, Knapp G, Reimers CD, 2018)

- Acute effect of alcohol intake on cardiovascular autonomic regulation during the first hours of sleep in a large real-world sample of Finnish employees: observational study (Pietilä J, Helander E, Korhonen I, Myllymäki T, Kujala UM, Lindholm H, 2018)

- The effects of physical activity on sleep: a meta-analytic review (Kredlow MA, Capozzoli MC, Hearon BA, Calkins AW, Otto MW, 2015)

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Educational summary of published research, not medical advice. Screening scores are not diagnoses. If a score is elevated or you feel unwell, talk to a clinician.

SleepShred for iPhone: https://apps.apple.com/app/id6802040541