What the 180 Formula is
Dr Philip Maffetone's method sets one ceiling for maximum aerobic function (MAF): the highest heart rate at which you train almost purely aerobically. The base is 180 − age. Subtract 10 if recovering from illness or surgery or on regular medication. Subtract 5 if injury-prone, new to training, or inconsistent. Keep it after two years of consistent, injury-free training. Add 5 only after two years of competing, improving, injury-free.
How to train with MAF
Keep almost all aerobic training between the ceiling minus 10 and the ceiling. Track progress with the MAF Test: after a warm-up, hold your MAF heart rate over a fixed distance and record the pace. Repeat every few weeks. A stall flags overtraining, poor nutrition, illness or stress.
Strengths and criticisms
MAF is simple and biased toward easy training, which most amateurs under-do. The criticism: 180 − age is a population rule, so some athletes get a ceiling well off their true aerobic threshold (LT1). Cross-check against lactate or LTHR data.
Worked example
A 35-year-old with 2 years of consistent, injury-free training (modifier 0):
| Base (180 − age) | 145 bpm |
| MAF aerobic ceiling | 145 bpm |
| Aerobic training range | 135–145 bpm |
An injury-prone athlete takes −5 and a 140 bpm ceiling.
Frequently asked questions
Is the MAF 180 Formula too slow?
The MAF 180 Formula feels slow at first by design. Most athletes find their MAF pace far easier than habitual training, which reveals an under-developed aerobic base. Pace at the same heart rate improves over weeks to months.
How is the MAF heart rate different from Zone 2?
MAF and Zone 2 overlap heavily. MAF is a single ceiling (180 − age, adjusted) rather than a band, and usually sits at the top of Zone 2. It is the stricter, single-number version.
Should the modifier ever be +5?
Use +5 only after more than two years of consistent training while still improving, competing, and injury-free. Most athletes should use 0 or a negative modifier. When in doubt, take the lower ceiling.
Sources
- Philip Maffetone, The Big Book of Endurance Training and Racing. The 180-Formula for maximum aerobic function (MAF).