# Fitbit resting heart rate high? Likely causes > A higher Fitbit resting heart rate usually has an ordinary cause: alcohol, caffeine, poor sleep, illness, a hard week. How to tell, and when to see a doctor. Published 2026-07-27, facts about other products checked 2026-10-09. Canonical page: https://pulse.portlabs.in/blog/fitbit-resting-heart-rate-high/ A resting heart rate that has crept up by a few beats per minute is most often alcohol, poor sleep, a hard training block, heat, caffeine, stress or the start of an illness. Google lists stress, alcohol, caffeine and fever. If it stays raised for more than a couple of weeks, or comes with symptoms, see a doctor. ## First, which number are you looking at? Your watch reports two heart rates that people constantly confuse. **Resting heart rate** is Google's estimate of "the number of times your heart beats per minute when you're still and well-rested". It is "estimated each day". Google's help page does not explain the method and points to a section inside the app. **Sleeping heart rate** is "detected continuously throughout the night", and Google notes it is often lower than your resting heart rate. So if your overnight graph dips to 52 and your resting heart rate says 58, nothing is broken. They are different measurements. Compare like with like over time: the daily resting figure against previous daily resting figures, and the sleeping curve against previous sleeping curves. *Figure: Resting heart rate is one estimate per day; sleeping heart rate is a continuous overnight reading, often lower. Definitions from Google's resting heart rate page.* In the app: open the Health tab, scroll to Key metrics and tap Resting heart rate. Google offers weekly, monthly, three-month and yearly views. ## What counts as high Google gives a broad range of 60 to 100 bpm that "varies depending on age and fitness level", and that is a population range, not your range. Someone who runs and sits at 48 and drifts to 56 has moved further, in relative terms, than someone going from 72 to 74. Your own trend is the useful comparison. A rise worth noticing is one that is larger than your usual day-to-day wobble and that holds for several days. There is no magic number, because there is no published threshold that applies to everyone. What can be said is that single-day spikes after a bad night are routine, and a flat week at a new higher level is more informative. *Figure: Resting heart rate with one spike that recovers next day, then a new higher level that holds. Illustration, not real data.* ## Causes, roughly in order of how often they are the answer ### 1. Alcohol Google lists alcohol directly. Even small amounts in the evening affect the heart overnight: in a study of wearable recordings from a large Finnish group (Pietilä et al., 2018), alcohol intake increased sympathetic activity and reduced parasympathetic activity in the first hours of sleep, with a dose-related effect, even at low intake. That study measured HRV-based recovery rather than resting heart rate alone, so treat it as a pointer, not proof about resting heart rate. ### 2. Short or poor sleep The NHS lists lack of sleep among common causes of a faster heartbeat. Check the [sleep score breakdown](/blog/fitbit-sleep-score-explained/) for how much of the night you actually slept soundly. ### 3. Caffeine, stress and everyday stimulants Google names both. A late coffee can show up in the night's curve, and a tense week at work often shows up as a flat, higher line. Nicotine and some recreational drugs also raise heart rate, and the NHS lists them alongside caffeine and alcohol among common causes of a fast heartbeat. ### 4. Training load and not enough rest A sudden jump in hard sessions, or a competition week, can lift resting heart rate for a few days. If it climbs over a block of training and does not settle with a rest day, that is a sensible sign to ease off. Google says regular exercise lowers resting heart rate over time, which is a longer-term effect than the short-term lift after a heavy session. ### 5. Illness coming on, or a fever Google lists fever. There is population-level evidence behind the idea too: Radin and colleagues (Lancet Digital Health, 2020) analysed Fitbit data from tens of thousands of users and found that weeks with more people showing elevated resting heart rate and longer sleep tracked influenza-like illness in their states, and improved forecasts over a model that used past case data alone. That says something about groups of people. For you, a raised resting heart rate, a cold or sore throat, and a bad night is simply a reasonable picture of a body fighting something. ### 6. Heat Google lists air temperature as an influence on heart rate, which fits a hot bedroom or a heatwave. ### 7. Medicines and medical causes Google notes certain medications can affect it. The NHS lists other possible causes of a fast heartbeat, including an overactive thyroid, iron deficiency anaemia, pregnancy and menopause. A new medicine, a change in dose, or a new condition is a good reason to mention a trend to a doctor. ### 8. The watch itself A wrist optical sensor can be wrong. A loose band, heavy movement or a stale sync can make a day's estimate odd. If one number looks implausible, check the sleep and daytime graph in the app, and wait for a second day before drawing conclusions. If you also see missing HRV, the checklist in [HRV zero or not tracked](/blog/fitbit-air-hrv-zero/) applies. ## A quick way to find the cause 1. Look back across two weeks of resting heart rate and mark the day it changed. 2. Match that day to what happened the evening before: alcohol, late meal, hard session, a travel day, a late bedtime. 3. Check whether the rise coincided with feeling ill, even slightly. 4. If nothing explains it, change one thing at a time for a week: no alcohol, caffeine before noon, a fixed bedtime. 5. If it is still raised after two to three weeks of ordinary life, or keeps rising, book an appointment. Your readiness or Recovery numbers will probably be dropping at the same time, because resting heart rate is one of their inputs. See [why Fitbit readiness is always low](/blog/fitbit-readiness-always-low/). ## When to see a doctor Resting above Google's 60 to 100 range while genuinely at rest, or a new sustained rise with dizziness, breathlessness, chest pain, fainting or palpitations, is worth a doctor's time. The NHS says to call 999 or go to A&E if palpitations do not go away, or come with chest pain, shortness of breath or fainting, and to see a GP if they keep coming back, happen more often or last longer than a few minutes. A watch cannot diagnose anything, so take the trend graph with you instead of trusting it. ## What Pulse does with it Pulse, a free app you host yourself, reads the daily resting heart rate Google sends and uses it in Recovery, Health Monitor and Pulse Age. If Google has no daily value for a day, it falls back to the lowest five-minute average during sleep ([how resting heart rate works in Pulse](/metrics/resting-heart-rate/)). Health Monitor flags a night that falls outside your own normal range. It is not a diagnosis, and it is built and tested with the Fitbit Air only. ## Sources 1. Google Health Help. [Resting heart rate](https://support.google.com/googlehealth/answer/14237938?hl=en) (checked 2026-10-09). 2. Google Health Help. [Health metrics in Google Health](https://support.google.com/googlehealth/answer/14236917?hl=en) (checked 2026-10-09). 3. Radin JM, Wineinger NE, Topol EJ, Steinhubl SR. [Harnessing wearable device data to improve state-level real-time surveillance of influenza-like illness in the USA](https://doi.org/10.1016/S2589-7500(19)30222-5). Lancet Digital Health 2020. 4. Pietilä J et al. [Acute effect of alcohol intake on cardiovascular autonomic regulation during the first hours of sleep](https://mental.jmir.org/2018/1/e23). JMIR Mental Health 2018. 5. NHS. [Heart palpitations](https://www.nhs.uk/conditions/heart-palpitations/).