The Age of Fitness Tracking
With the rise of smartwatches and fitness trackers, it’s easier than ever to monitor your heart rate throughout the day. Your heart beats nearly once every second — that’s a huge amount of health data available at your fingertips. But what does your resting heart rate (RHR) actually say about your health?
Surprisingly, a simple RHR reading — measured while you’re completely at rest — can reveal a lot about your cardiovascular fitness, stress levels, and even your risk of chronic illness. Best of all, you don’t need fancy tech to track it.
What Is a Normal Resting Heart Rate?
For most adults, a normal resting heart rate ranges from 60 to 100 beats per minute (bpm).
Having a heart rate in this range reduces strain on your heart muscle, allowing it to work more efficiently. As Kate Traynor, M.S., R.N., from Massachusetts General Hospital explains:
“Think of your heart as a car and your blood’s oxygen as the gas. The faster you drive, the more gas you use [the more blood that needs to be pumped]. More gas means more work for the heart, which can put it in constant overdrive,” says Traynor.
What Causes a High Resting Heart Rate?
A heart rate above 100 bpm is known as tachycardia. While occasional spikes are normal, persistently high RHR can signal underlying issues.
Common causes include:
- Fever or dehydration
- Anemia
- Physical or emotional stress
- Overuse of caffeine or stimulants
- Hyperthyroidism
- Lack of physical activity
A study found that people with a resting heart rate over 84 bpm had a 55% higher risk of dying from heart disease over five years.
What About a Low Resting Heart Rate?
If your resting heart rate is below 60 bpm, it’s known as bradycardia. For some, this is a sign of excellent fitness — especially athletes. But for others, it could indicate a medical concern.
Low RHR may cause:
- Dizziness or lightheadedness
- Fatigue
- Fainting
- Poor blood flow to the brain
“Not all low heart rates are bad,” says Dr. Suneet Singh. “Endurance athletes often have RHRs below 40 bpm due to higher cardiac efficiency.”
Other causes of bradycardia include:
- Hypothyroidism
- Heart rhythm disorders
- Certain medications (e.g., beta-blockers)
- Aging
