Train in the right heart-rate zone
Zone 2 gets all the attention for a reason — but you need the numbers first.
Tools used in this guide
The job
A 35-year-old has an estimated max HR of 185 bpm. Zone 2 — the easy endurance zone — sits at 60–70% of that, roughly 111–130 bpm. Five zones divide the range from recovery to maximum effort.
Refining with resting HR
Adding your resting heart rate switches to the Karvonen method, which counts the reserve between resting and max — same percentages, but personalized. Measure resting HR lying down, right after waking.
Using the zones
Zone 2 should feel easy enough to hold a conversation — most endurance volume lives there. Zones 4–5 are for intervals and races.
220−age is a population average; real max HR varies by ±10–15 bpm. Treat the zones as starting rails, and adjust by feel (or a lab test) if they run consistently hard or easy.