What max heart rate is actually for in a training plan
Your heart has a ceiling: the number of beats per minute it will not go past, even when you empty the tank over the last few meters. That ceiling has a name, maximum heart rate, written HRmax. It does not measure your level — a weekend jogger and a marathon runner can share the same value. It works as a scale. From it, effort gets carved into zones, and each zone builds a specific quality. Without that reference point, an “easy” run ends up too fast far too often, and a session meant to hurt stays lukewarm.
How to calculate your maximum heart rate
Estimation formulas: quick, but rough
The best known is still 220 minus your age. At 40, that gives 180 beats. Simple, but the real gap is often ten to twelve beats either way. The Tanaka formula, 208 minus 0.7 times your age, tracks reality better in athletes over 45. Take any formula as a starting point, never a fact: two people the same age can be twenty beats apart.
The field test, the most useful method
To get a number that belongs to you, you have to go and find it. After twenty minutes of progressive warm-up, pick a steady hill or a track. Raise the intensity in two-minute steps, then finish with three minutes of hard acceleration, until you can no longer hold the pace. The peak your chest strap records in the seconds that follow is your HRmax for the day. Write down the date, the route and the weather: you will want to compare later. This test takes real motivation and a healthy body — it is not a casual workout.
The lab stress test
The medical stress test remains the reference. Run on a treadmill or a bike ergometer with a cardiologist, it measures the exact value while monitoring your heart's trace. Past 35, with a family history, or coming back after a long break, ask for this exam before any high-intensity work. Staying healthy comes before performance.
The five training zones and what they build
Once you know the value, the math is direct: each zone matches a percentage. Here is the breakdown most coaches use.
- Zone 1, 50 to 60%: active recovery. You can talk without effort, the movement stays loose. Perfect the day after a hard session.
- Zone 2, 60 to 70%: base endurance. The body learns to draw on fat and builds mitochondria. This is the zone that should take up the most time.
- Zone 3, 70 to 80%: tempo pace, comfortably hard. Useful, but settling in here too often tires you out without making you better.
- Zone 4, 80 to 90%: around threshold. Lactate builds up, breathing gets short. You work here in blocks of five to ten minutes.
- Zone 5, 90 to 100%: maximal aerobic power. Bouts of thirty seconds to three minutes, with full recovery between each one.
One detail escapes a lot of athletes: heart rate climbs with a delay. On a thirty-second rep, your watch may show 82% while the real intensity was well past zone 5. On very short efforts, trust pace or power, not your pulse.
Heart rate reserve, a sharper split
The Karvonen method refines the calculation by bringing in your resting heart rate, taken in the morning before you get up. Subtract that resting value from HRmax to get your reserve, apply the percentage, then add the resting value back. An example says it better than a rule: 190 max, 50 at rest, so a reserve of 140. To target 70%, work out 140 × 0.70 = 98, then 98 + 50 = 148 beats. A plain percentage of HRmax would have given 133, a much lower zone. For someone very well trained, whose resting rate drops below 45, the gap widens further.
Spreading intensities across the week
The endurance world agrees on one principle: around 80% of your volume in zones 1 and 2, 20% in zones 4 and 5. This polarized model gives better results than training forever at a middling zone 3. In practice, across four sessions a week, three stay slow and only one bites hard. The difficulty is not technical, it is mental: running slowly means accepting that people will pass you. Plenty of runners improve simply by easing off three times out of four. The same balance holds on the bike and on the rower.
What moves your numbers day to day
HRmax drops with age, by roughly one beat a year, and training does not bring it back up: it improves how much the heart sends out with each beat. The rate you read during a session, though, swings a lot. Heat, dehydration, poor sleep, coffee or the start of a bug all push it higher. On a long session, cardiac drift adds five to ten beats even at a steady pace.
Each discipline has its own ceiling too. On the bike, the value falls five to ten beats compared with running, because less muscle mass is working in a seated position. In swimming, the horizontal position widens the gap further. So set a reference per sport, not one single number. On the hardware side, the optical sensor on your wrist loses the signal as soon as intensity changes fast or cold cuts blood flow. For zone 4 and 5 sessions, a chest strap becomes necessary if you want data you can use.
What about strength training?
In the gym, zones lose their meaning. A heavy set drives your pulse up through the resistance placed on the muscle and through breath-holding, not through oxygen demand: the number climbs, the cardio load stays low. In a circuit run back to back with no pause, on the other hand, heart rate becomes a good indicator of density: if it drops too far between two stations, cut the recovery short. Keep zone-based pacing for cardio, and judge strength by the loads you lift and how cleanly you execute the movement.
Common questions about HRmax
Is it dangerous to reach your max heart rate?
In a healthy person, no: it is a normal physiological limit, not a breaking point. Caution is needed if you get chest pain, dizziness, irregular palpitations or breathlessness out of proportion to the effort. Stop the session and see a doctor.
My HRmax is lower than my partner's, is that a bad sign?
No. This value is largely genetic, in the same way your height is. It says nothing about your endurance. Compare your progress with your own, not with the person in the next lane.
Should you redo the test every year?
A check every twelve to eighteen months is enough. Above all, recalculate your zones if your usual paces no longer match the expected percentages, especially after an injury.
Can you train without a heart rate monitor?
Yes. The talk test is still remarkably effective: full sentences in zone 2, short sentences in zone 3, single words beyond that.
From numbers to a plan that holds up
Knowing your max heart rate is not enough: you still need to know what to do with it given your goal, your race calendar and the time you have. A coach checks that your zones, your real paces and how you feel line up, then adjusts sessions week after week. On Koatcher, you can rethink your approach with a coach who specializes in running, at home, in a gym or online, in Paris and anywhere else. The aim stays the same: turning a table of percentages into training that makes you better without breaking you.