TRAINING TERMS
Zone 3
The first of the App’s higher working bands; movement can be continuous or divided into bouts.
70% to below 80% of reserve
Zone 3 starts at resting heart rate + 70% of reserve and ends just below resting heart rate + 80% of reserve. The percentages refer to the gap between resting heart rate and estimated maximum, not to maximum heart rate alone.
Higher work needs room in the whole session
The App considers actual training history, recent harder activity, body information and available time before selecting a higher zone. Zone 3 work can be continuous or divided into bouts. Preparation, recovery where needed, and cooldown still belong to the session.
A band is not a threshold test
This label does not identify your lactate threshold or guarantee a particular breathing pattern. Consider the session’s structure alongside your sense of effort. Crossing into Zone 3 during an activity does not by itself mean the next session should target it.
Sources & further reading
Reviewed September 14, 2026