Maffetone Method: What and How
The Maffetone method is based on heart rate training. When heart rate monitors first became available, Dr Phil Maffetone began to research their use extensively. He determined that the best use of a heart monitor is to ensure that one is training aerobically, and not unintentionally (or intentionally) going too hard. The problem is finding what the correct heart rate. Most people who have been around exercise know about the 220 formula for determining training zones. You subtract your age from 220 to get an approximate maximum heart rate and base your training around that. The problem is that it is too inaccurate for most people. Some then do a field test to find out what their true maximum is and go from there. Most coaches go off percentages of lactate threshold heart rate instead of maximum. This entails a field test where you determine the average heart rate over a 30-60 minimum all out effort. This was believed to be the highest intensity one could sustain before lactate built up faster than it could be cleared.
Maffetone had a different idea. Rather than define “aerobic” or “anaerobic” in terms of oxygen or lactate, he chose to define it as whether fat or carbohydrate was the primary fuel source for the muscles. He terms aerobic to be when the slow twitch muscle fibers predominate and burn primarily fat for fuel. Anaerobic is when the fast twitch muscle fibers take over and are burning primarily stored carbohydrate. The Maffetone Method is based on doing most of one’s training at the level where fat is the primary fuel source, and not going so hard as to switch over to carb burning metabolism. This happens at a relatively low heart rate. It can be determined precisely in the lab by doing gas analysis of breathing.
But most people don’t have access to a lab, so Maffetone looked for a formula that could approximate the correct heart rate. By doing the math backwards from lots of data, he came up with his “180 Formula”. Subtract your age from 180 and you have the maximum heart rate you should train at to stay aerobic. There are a few modifiers for special situations, but otherwise you take that number and train as close as you can to it, what Maffetone calls your Maximum Aerobic Function. Anaerobic training is for competitive athletes and for short periods only. By training at this low heart rate, eventually you will get faster as your body adapts by producing more and more energy aerobically and from fat, sparing the carbohydrate stores. The end result is going farther, faster, and easier. Even racing at a much higher heart rate is affected by the fitness built at the much lower M.A.F. heart rate.
Here is Maffetone’s own explanation
Here is Mark Allen’s version
More can be found in Maffetone’s current books: