Resting heart rate (RHR) is the simplest, most underrated number in fitness. It's free, it's sensitive, and it quietly tells you a lot about your health and training. Here's how to read it.
What is resting heart rate?
It's how many times your heart beats per minute when you're completely at rest — ideally measured first thing in the morning, before you get up. A wearable measures it overnight automatically.
What's a normal resting heart rate?
For most adults, a normal RHR sits between 60 and 100 bpm. But "normal" and "good" aren't the same thing. Well-trained endurance athletes often sit in the 40s or low 50s, because a stronger heart pumps more blood per beat and needs fewer beats. A lower RHR (within healthy reason) generally signals better cardiovascular fitness.
Why a lower RHR usually means fitter
As you build aerobic fitness, your heart becomes more efficient. Over months of consistent training, many people watch their resting heart rate drift down by several beats — one of the most satisfying, concrete signs that training is working. It's a great long-term fitness metric to track.
What makes it rise
A short-term jump of several beats above your normal is a useful warning. Common causes:
- Hard or unusually long training the day before
- Poor or short sleep
- Dehydration, alcohol or late caffeine
- Stress
- An illness brewing — RHR often climbs a day before you feel sick
How to use it
Like HRV, read the trend, not the single number. Establish your normal morning RHR, then watch for sustained deviations:
- Trending down over months → fitness improving. Nice work.
- Spiked for a few mornings → fatigue, stress or illness. Take an easier day and prioritize recovery.
Paired with HRV, resting heart rate is half of a powerful, no-effort early-warning system — both come straight from your wearable while you sleep.
Your morning heart rate is a free daily health check. Learn your normal, and pay attention when it changes.
Track it over time and let the trend, not any single morning, guide how hard you train today.