When you exercise, your heart rate rises to meet your muscles’ demand for energy and oxygen. How high your heart rate gets reflects how hard you’re working. Heart rate zones are just ranges of beats per minute (bpm) that help you understand exercise intensity relative to your maximum heart rate (MHR), which you can estimate by subtracting your age from 220.
The six heart rate zones
Beloware the six heart rate into zones, each tied to a percentage of your MHR and a different level of effort:
- Zone 0 (≤49%) — very gentle movement or recovery
- Zone 1 (50-59%) — light pace, easy breathing, good for warm-ups, cool-downs and metabolic health
- Zone 2 (60-69%) — light to moderate, sustainable effort, building endurance
- Zone 3 (70-79%) — moderate-high intensity, harder to chat
- Zone 4 (80-89%) — high intensity near maximal effort
- Zone 5 (90-100%) — all-out, breathless, strong cardiovascular stimulus
A simple rule of thumb is that Zones 0-1 are low intensity, Zones 2-3 moderate, and Zones 4-5 high intensity.
Why the zones matter
Each zone has its place and health benefit:
higher zones (especially above about 80% of MHR) can:
• improve cardiorespiratory fitness faster than lower intensities
• boost insulin sensitivity
• help maintain or build muscle
• increase maximal oxygen uptake (VO₂ max)
• be time-efficient for cardiovascular gains
lower zones aren’t “wasted time” either — they:
• activate the parasympathetic (rest and digest) system
• support heart health and energy balance
• help with recovery and reduce stress
• are accessible and safe for most people
Importantly, you don’t need to push to high heart rates every session to be healthy — a mix of zones across your week tends to give the best overall results.
Bottom line
Heart rate zones are a practical way to tailor your exercise so it meets your goals — whether you’re after endurance, strength, fat loss or just general wellbeing. Low intensity counts and supports consistency, while higher intensity can accelerate specific adaptations. A balanced approach that includes a range of heart rate zones usually gives the best overall health and performance outcomes.