Nes et al. Max Heart Rate Formula: Sex-Specific MHR Estimates
Two people, same age, different max heart rates. That's the premise behind the Nes et al. max heart formula, and it's a departure from almost every other age-based equation in this space.
The Two Equations
Men: MHR = 211 − (0.64 × age)
Women: MHR = 210 − (0.67 × age)
The starting constants are close — 211 versus 210 — but the per-year decline rate differs: 0.64 beats per year for men, 0.67 for women. That gap widens with age. At 25, the two formulas produce estimates within a beat or two of each other. At 65, the gap has grown to several beats.
Why Sex Enters the Equation
The traditional "220 minus age" formula treats every athlete the same regardless of sex, and research behind formulas like Nes et al. has pointed to that as one of its blind spots. Cardiovascular research has documented differences in how maximum heart rate declines with age between men and women, and the Nes et al. formula was built to reflect that rather than average it away.
That doesn't mean the formula is perfect. It means it corrects for one known variable that older formulas ignored.
The Math, Shown in Full
A 45-year-old man: 211 − (0.64 × 45) 211 − 28.8 = 182.2, rounded to 182 bpm
A 45-year-old woman, same age: 210 − (0.67 × 45) 210 − 30.15 = 179.85, rounded to 180 bpm
Same age, two-beat difference. At younger ages the gap is smaller; at older ages it widens further, since the female formula subtracts more per year than the male one.
Turning the Estimate Into Zones
A max heart rate number is only the input. The output that matters day to day is the training zone structure built on top of it.
Zone 1 (50–60% of MHR): Recovery, warm-ups, cooldowns, and easy aerobic movement.
Zone 2 (60–70% of MHR): Aerobic endurance, long sessions, and base development.
Zone 3 (70–80% of MHR): Tempo work, steady endurance, and moderate race-specific effort.
Zone 4 (80–90% of MHR): Threshold training, sustained intervals, and controlled hard efforts.
Zone 5 (90–100% of MHR): VO2 max work, short intervals, and high-intensity sessions.
For the 182 bpm estimate above, Zone 3 sits between roughly 127 and 146 bpm. For the 180 bpm estimate, that same zone sits between 126 and 144 bpm — close, but not identical, which is exactly the kind of small shift that a sex-specific formula is built to capture.
What Holds Up, What Doesn't
The formula's strength is straightforward: it requires only age and sex, it's fast to calculate, and it's grounded in research data rather than an unverified rule of thumb. Its limitation is just as straightforward: age and sex are still the only two variables in the equation. Fitness level, training history, and medications that affect heart rate play no role in the number it produces. It also treats sex as a binary input, which won't map cleanly onto every athlete's physiology, and it doesn't adjust for the sport-specific gap between, say, running and cycling heart rates.
None of that erases its value — it just means the number is a starting point, not a verdict.
Applying It Across Three Sports
For triathletes, small heart rate errors don't stay small for long. They compound across swim, bike, and run, and across a full training week they can turn what should be an easy day into accumulated fatigue. Heart rate on a bike typically runs 8 to 12 bpm lower than running at the same effort, and swimming lower still — a detail worth building into zones derived from any age-based formula, including this one.
FAQ'S
What is the Nes et al. max heart rate formula? It's a pair of equations — one for men, one for women — that estimate maximum heart rate based on age, using different rates of decline for each sex.
Why does the formula differ by sex? Research behind the formula found that maximum heart rate declines at a different rate with age between men and women, and the equation reflects that instead of using one blended number for everyone.
Is this formula more accurate than 220 minus age? It's generally considered an improvement, mainly because it accounts for sex differences that "220 minus age" ignores entirely. It still shares the same core limitation of using age as its only real variable.
Does the formula account for fitness level? No. It uses age and sex only. Two athletes of the same age and sex with very different training backgrounds would still receive the same estimate.
Where the Number Goes From Here
A max heart rate estimate sets the frame; a training plan is what actually uses it. Andiamo²® training plans apply heart rate, pace, and power together across swim, bike, and run, so the number translates into real weekly structure.
Curious what your zones would look like inside a full plan? Grab the Splash Class below and enter your email for a free twelve week swim and strength plan — a no-cost, no-pressure way to try the Andiamo²® coaching structure in your own training week.
Thanks for reading.
