I have used oura ring since 2017, that’s now little bit over 1000 days. I’m going to explain here what have I learned about HRV and what science says. You can read full blog post here with illustrated pictures and sources: https://ilmostromberg.com/1000-days-with-oura-ring/ but I’m also giving shorter version here:
HRV - Why measure it?
High HRV indicates good recovery and general fitness and low HRV opposite
HRV gives more insight than heart rate, example upcoming illness can be potentially seen on HRV values
Abnormally low HRV for long time can also indicate upcoming heart attack.
For me as a athlete, its important variable to monitor. I want to train hard but avoid overtraining.
Nightime HRV values gives me good signal for the day: how hard should I push in the training today?
HRV - My normal values
I can guess my night time HRV with 90% confidence ±5. My confidence is based purely on what I did previous day
My average HRV is 70, and it normally fluctuates ± 10. I take it easy with training if my HRV is under 60, but its not strict rule
HRV - Exceptionally high values
I have noticed that my body goes to special recovery mode in following situation:
Low HRV and high pulse in day 1 because of heavy training or stress. My HRV rebounds in day 2, typically 80-90 range.
Day after heavy drinking (I call it hyper recovery)
High HRV is not always good, that can be sign of overtraining (more info on blogpost)
HRV - Exceptionally low values
I have recognize 3 different situations where my HRV is abnormally low. First one is physically exhausting training, example long distance running.
With heavy drinking my HRV was close to zero!
Fever (It’s important to point out that my heavy day of drinking was in same HRV range than high fever, so alcohol in moderation ladies and gentlemen!)
HRV - Correlations with other Oura data points
If I want to have good HRV, then based on Oura data I should: spend more time in bed and have lots of sleep, go early to bed and have low heart rate / respiratory rate.
HRV - Correlation with mood
I track my mood with Daylio. Data from Daylio shows that my happiness is 3,9 when HRV is under 60. My happiness is 4,1 when HRV is either 60-70 or over 70
Connecting HRV to mood is not new idea: Study published in 2018 stated that there is bidirectional connection between HRV and depression, autonomic function affecting depression risk, not vice versa as previously thought.
Do’s and Dont’s
There are many different ways to increase your HRV, do’s and dont’s. One of my favorite is acupressure mat 20 minutes before bed to give good jump start to HRV. How to increase your HRV in short term and long term is explained in blog post more thoroughly.
Any comment is appreciated, hopefully this gave some valuable information for you. Thank you!