opti · Exercise Science
Burn Fat Efficiently: Pulse Zone + kcal per Hour
Tap any element to learn more · Based on a 75 kg adult, moderate fitness level
Fat burning zone diagram: pulse gauge showing 65-75% max heart rate, talk test bubble, vertical bar chart of kcal per hour by sport
Aerobic zone: fat is the preferred fuel · 65–75% of max heart rate
Low
High
65%
75%
Warm-up
FAT BURN
Cardio+
YOUR ZONE
65–75%
Quick formula:
170 − age
(or: (220 − age) × 0.65–0.75)
Talk test:
Still able to speak
in full sentences ✓
"Can you
still talk?"
→ You're in the zone
0
400
500
600
kcal/h
🔥 fat burn zone
350
450
450
500
550
550
🚶
Walk
🤸
Aerobics
🚴
Cycling
⚽
Ball
🏃
Jogging
🏋️
Strength
Aerobic (moderate):
Fat is the preferred fuel · can sustain for hours
Brisk walking already qualifies ✓
High intensity:
More total kcal burned per session
Carbs become the dominant fuel
✕