MAF method vs Zone 2 training
The MAF method and Zone 2 training are both ways to keep easy runs truly easy: MAF gives you a single heart rate ceiling from the formula 180 minus your age, while Zone 2 gives you a range based on a percentage of your max heart rate or heart rate reserve. For many runners the two land within a few beats of each other, so the bigger difference is in the rules around them, not the numbers.
What the MAF method is
MAF stands for Maximum Aerobic Function, an approach developed by coach and author Phil Maffetone. You find your MAF heart rate with the "180 formula":
- Start with 180 minus your age.
- Subtract 10 if you're recovering from a major illness or surgery, or take regular medication.
- Subtract 5 if you're new to training, coming back from injury, training inconsistently, or often get colds.
- Keep the number as is if you've trained consistently for up to two years without those problems.
- Add 5 if you've trained for more than two years without problems and are still improving.
That number is your ceiling. Most aerobic runs are done between it and 10 beats below it, often for weeks or months before adding any faster running. Progress is tracked with a "MAF test": run a set distance at your MAF heart rate every few weeks and watch your pace get faster.
What Zone 2 training is
Zone 2 is the second of five heart rate zones, usually set at 60–70% of your max heart rate, or 60–70% of your heart rate reserve if you know your resting heart rate (the Karvonen method). It feels easy and conversational. Most Zone 2 approaches use it for the bulk of your running, around 80% of your weekly time, with a smaller amount of harder work. What Zone 2 running is covers the basics, and the Zone 2 calculator works out your range.
How the numbers compare
Here's how the ranges compare for a runner with no MAF adjustments, using 220 minus age for max heart rate and a resting heart rate of 60 bpm for the Karvonen column.
| Age | MAF range | Zone 2 (% of max HR) | Zone 2 (Karvonen, RHR 60) |
|---|---|---|---|
| 25 | 145–155 bpm | 117–137 bpm | 141–155 bpm |
| 35 | 135–145 bpm | 111–130 bpm | 135–148 bpm |
| 45 | 125–135 bpm | 105–122 bpm | 129–141 bpm |
| 55 | 115–125 bpm | 99–115 bpm | 123–134 bpm |
Two things stand out. MAF is close to a Karvonen-based Zone 2, especially for younger runners. And MAF sits well above a simple percent-of-max Zone 2, which is one reason runners using different methods end up arguing about what "easy" means. All of these are estimates; your real numbers depend on your own max and resting heart rate.
MAF vs Zone 2 at a glance
| MAF method | Zone 2 | |
|---|---|---|
| How it's set | 180 minus age, with adjustments | % of max HR or heart rate reserve |
| Target | A ceiling, usually trained 0–10 beats below | A range (one of five zones) |
| Faster running | Avoided during the base phase | Usually a small part of each week |
| Progress check | Regular MAF test at a fixed heart rate | Pace at the same heart rate over time |
| Extra advice | Also covers diet and stress | Training only |
Pros and cons
MAF method
- Pros: one simple number, no need to know your max heart rate, and a built-in progress test.
- Cons: the formula ignores individual differences in max heart rate, so it can be too easy for some runners and too hard for others. A long base phase with no faster running can feel restrictive.
Zone 2
- Pros: fits into a full five-zone system, can be personalised with your resting heart rate, and pairs easy running with some faster sessions.
- Cons: the percentages and formulas vary between apps and watches, which can be confusing, and percent-of-max ranges can feel very slow at first (here's why).
Which should you use?
- Use MAF if you like one clear number and a strict aerobic base phase, and you don't know your max heart rate.
- Use Zone 2 if you want a range that accounts for your resting heart rate and a plan that includes some faster running as you get fitter.
- Either way, sanity-check the number with the talk test. If you can't speak in full sentences, you're working harder than either method intends.
The method matters less than the habit. Running easy most of the time, consistently, for months is what makes both work. For a realistic timeline, see how long Zone 2 takes to work.
This is general fitness information, not medical advice. If you have a heart condition, take medication that affects heart rate, or have other health concerns, check with your doctor before starting heart rate training.
Train by heart rate without doing the maths
RunZone builds Zone 2-based plans, from 5K to marathon plus general fitness and weight loss, coaches you live with voice cues while the app is open, and charts your pace getting faster at the same heart rate. Use Apple Watch heart rate via Apple Health, or pace-only coaching with just your iPhone.
Download RunZoneFAQ
Is MAF the same as Zone 2?
Not exactly. MAF is a single heart rate ceiling from 180 minus your age, while Zone 2 is a range based on your max heart rate or heart rate reserve. For many runners they overlap closely, but MAF is often higher than a simple percent-of-max Zone 2.
What is the MAF heart rate for a 40 year old?
Using the 180 formula with no adjustments, it's 140 bpm, so most aerobic runs would sit between 130 and 140 bpm. Subtract 5 if you're new to training or coming back from injury.
Is the MAF method good for beginners?
It can be, because it keeps runs easy and gives you one clear number. Many beginners will need walk breaks to stay under their MAF heart rate at first, which is normal.