Maffetone MAF heart rate

Phil Maffetone's 180 formula gives the ceiling for aerobic base training: the highest heart rate at which you are still building your aerobic engine rather than borrowing from it.

Age (years)

Which of these describes you best?

Recovering, hospitalised, or on medication (-10) Recovering from a major illness or operation, recently hospitalised, or taking regular medication. Injured, inconsistent, or getting ill often (-5) Injured, gone backwards in training or racing, more than two colds or flu bouts a year, allergies or asthma, or just getting into (or back into) training. Training consistently for up to two years (0) Training consistently for up to two years with no injuries and no more than two colds or flu bouts a year. Two-plus years, injury free and improving (+5) More than two years of consistent training with none of the problems above, and still improving in competition without injury.

Couldn't calculate

Your MAF heart rate

140 bpm

Train in 130–140 bpm — the 10-beat window below your MAF heart rate.

180 − age	140
Category adjustment	0
Extra beats (65 or older)	0
MAF heart rate	140

How to use it

Take 180 − your age, then apply the one adjustment that fits your health and training history. The result is a ceiling, not a target: all your aerobic work should sit at or below it, ideally in the 10-beat window just underneath.

Two exceptions ride on top of the formula. Athletes 16 and under use a flat 165 bpm instead. Athletes 65 and older who are two-plus years in, injury free and still improving may add up to 5 beats beyond the usual +5, for up to +10.

The number is meant to move. Recalculate when your category changes, and run a repeated MAF test — same route, same heart rate, timed — to check whether your aerobic speed at this heart rate is improving. If it stalls or goes backwards, that is the signal to look at recovery, stress and fuelling rather than to push the number up.