Many runners have probably been told to “go slow to go fast,” and that the best approach to long runs is to take them nice and easy. According to Dr. Phil Maffetone, you might need to slow down even further if you want to see more PBs in your future. Maffetone employs what he calls the 180 formula to determine an athlete’s “individualized submaximal heart rate,” or MAF HR, which stands for Maximum Aerobic Function Heart Rate. This formula can lead to enormous improvements in a runner’s efficiency and speed, and while it might be tough to get started with the MAF training plan, the benefits are well worth it.
Calculating your MAF HR
It’s pretty easy to calculate your MAF HR using Maffetone’s 180 Formula. Start by subtracting your age from 180. (Many people recommend subtracting your age from 220 to find your max heart rate, but Maffetone says this is far too high to elicit the aerobic benefits possible at a considerably lower heart rate.) Next, your health and current training are taken into consideration. If you’re dealing with a major illness, undergoing rehab from any medical procedures or taking any regular medications, subtract another 10 points. Subtract five points if you’ve seen a drop in your training or if you’re sick. If you have trained consistently (at least four times per week) over the last two years and don’t fit any of the above criteria, your MAF HR is 180 minus your age with no adjustments necessary.
Putting MAF to use
Here’s where you’ll probably need to slow your runs down. If your maximum aerobic heart rate is 140 beats per minute (BPM), you need to aim to stay at or below this for the entirety of your run. This is quite low, which is why MAF training requires patience. At first, running at such a low heart rate will feel like little more than a shuffle. But as your volume at this low heart rate increases, so will your pace.
As maddening as running at a snail’s pace will be, don’t worry, because it won’t stay that way for long. Perform a MAF test each month to monitor your progress with the training program to see the benefits for yourself. As Maffetone outlines on his website, the test should be one to five miles long, and you should take note of every mile split. Start with a 12- to 15-minute warmup, then run the main set at your maximum aerobic heart rate. Month by month, you should see these times drop. Your heart rate will remain the same for every MAF test, but you’ll be hitting slightly faster paces with every run.
The MAF method has been used by many runners, most notably six-time Ironman triathlon world champion Mark Allen, who said he turned to this program after years of overtraining, which led to injuries and burnout. With MAF training, Allen says, “You gain fitness without burning yourself out, you gain fitness without compromising your immune system, you gain fitness without destroying yourself mentally.” Allen started off with MAF by training aerobically as a test for two months, and he “went into [a triathlon] off of pure base training, and I destroyed the field. And I thought, ‘There’s something to this.'”
Keep it slow
It should also be noted that MAF training requires you to only run slow for the first few months of the program. It’s all about training your aerobic system and slow-twitch muscle fibres, and if you throw speed sessions into the mix too soon, you’ll disrupt the whole process, effectively wasting all the time you’ve spent running slowly. In keeping with the program long enough, you will eventually reach your former pace, but your heart rate will be much lower than it was before you started MAF training (which is ultimately healthier). Once you reach this level, you can re-incorporate speed work into your training schedule, and your speed will be there when you need it when you enter races or time trials.
Another benefit of MAF training is the fact that running slowly is a great way to avoid injuries. This is especially good for new runners, as the desire to run fast can be overwhelming at times. If you have a set heart rate for your runs, though, you can’t go too fast, therefore saving yourself from any potential injuries.
If you stick to your max aerobic zone in all your runs, you’ll become more efficient and use less energy, and then you’ll see your times improve while still being able to maintain that same heart rate. As runners, we all want to go fast, but staying true to the MAF program and 180 Formula has the potential for a huge payoff in the end.