Easy is Zone 2: roughly 60–70% of your maximum heart rate. Estimate your max with the Tanaka formula — 208 minus 0.7 times your age — and a 35-year-old comes out at about 184 bpm, which puts an honest easy run at 110–128 bpm. No chest strap on you? The talk test gets you most of the way there without one: if you cannot hold a full sentence without gasping for the next word, you are not running easy, whatever the pace on your watch says. Plug your own age, or your measured max and resting heart rate, into the heart rate zones calculator for the exact numbers — the rest of this is about why most runners miss both checks anyway.
The five zones, and where 60–70% sits
Training zones run from Zone 1, recovery, at 50–60% of max, up to Zone 5, VO₂ max, at 90–100%, with easy running living in Zone 2 at 60–70%. Add your resting heart rate and the calculation switches from the flat age-based estimate to the Karvonen method — target heart rate equals resting rate plus reserve times intensity percent — which anchors the zones to your own fitness rather than to a population average. The plain 220-minus-age formula still stapled to gym walls has an error margin of roughly ±10–12 bpm for an individual, wide enough to put someone’s real Zone 2 inside what their watch is calling Zone 3. Tanaka’s 208 − 0.7 × age tightens that considerably, and a measured max from an actual hard hill rep or race finish beats either formula.
- Zone 1 — recovery (50–60%). Shakeout runs, the day after a hard session.
- Zone 2 — easy / aerobic (60–70%). Where most of a runner’s week should live.
- Zone 3 — tempo (70–80%). “Comfortably hard” — and where most easy runs actually end up.
- Zone 4 — threshold (80–90%). The edge of what you can sustain.
- Zone 5 — VO₂ max (90–100%). Short, sharp, reserved for intervals.
The gap between the two methods is not academic. Take a 40-year-old with a measured max of 180 bpm and a resting heart rate of 55 bpm: Karvonen puts their heart rate reserve at 125, so Zone 2 lands at 130–142 bpm. Estimate the same runner’s zones from max alone, no resting rate involved, and the range comes out at 108–126 bpm — roughly 20 beats lower at the bottom end. Neither number is wrong, but only the Karvonen one is describing this particular runner rather than a generic percentage of their ceiling. That gap is exactly why the calculator asks for a resting heart rate at all, and exactly why an easy run that “should” be 108 bpm by the simple formula can still feel wrong for someone whose real Zone 2 sits 20 beats higher.
The talk test is a cross-check, not a downgrade
A heart rate number is only as good as the max it was calculated from, and most runners are working from a guess. That is what makes the talk test worth keeping even once you own a strap: if you can speak in full sentences, you are almost certainly in Zone 1 or 2, regardless of what an unverified max is telling the watch. If you can only manage a few words at a time, you have drifted into Zone 3 even if the display still reads a number that looks fine on paper. Use the two together — the bpm range as the target, the conversation as the sanity check on whether that range is actually right for you.
The uncomfortable part: your easy pace is slower than you think
This is where most runners fail the test they just passed on paper. A comfortable easy pace for many recreational runners sits around 6:00–7:00 per kilometre — noticeably slower than the pace that feels “normal” once a training log or a running club is involved. Run that same easy day at what feels like a respectable pace instead of an honestly easy one, and the heart rate follows it straight past 70% and into Zone 3: fast enough to accumulate fatigue, not fast enough to earn the adaptation Zone 5 work is designed for. Zone 3 is not a mistake anyone makes on purpose — it is what happens by default when “easy” gets defined by ego rather than by a number on a strap. Run your own recent times through the pace calculator to see where your usual “easy” actually sits.
What holding the zone actually buys you
The popular 80/20 approach — roughly 80% of weekly training time in Zones 1–2, 20% in Zones 3–5 — is not a rule for its own sake. It is what most endurance training keeps landing on: the aerobic base gets built by volume at a genuinely low intensity, and the sharp end gets sharper by staying sharp rather than by living in the tired middle. Skipping the discipline does not make a runner fitter faster; it mostly means every session costs about the same in fatigue, easy and hard alike, which is the fastest route to a plateau a plan on paper cannot explain.
None of this needs a lab. Work out your zones once with the heart rate zones calculator, find what that easy pace actually looks like on the road with the pace calculator, and then do the harder part: running slow enough, on purpose, on the days that are supposed to be slow. And when the block that easy running quietly built is done, Skoma turns the training and the race photos into a book — the boring, unglamorous weeks included, because they were most of the work.