New Maffetone Formula for 2025
Dr. Phil has 2 New Updates
Hey runners, are you ready to start burning fat on your training runs? Today, we’ll delve into Dr. Phil Maffetone's new updates to his Maximum Aerobic Function (MAF) formula to fine-tune your training heart rate for optimal fat burning. We'll also explore my unique “Reverse MAF” approach for runners in their 50s, 60s, or 70s.
Watch this Post on YouTube
Introduction to Maximum Aerobic Function (MAF)
Before we dive into the updates, it's essential to understand what Maximum Aerobic Function is and its significance.
Our bodies are designed to rely on fat as a primary energy source for sustained, low-intensity physical activities, like training runs.
Developed by Dr. Phil Maffetone over the past 40 years, MAF is a heart rate training method aimed at enhancing health, preventing disease, and boosting athletic performance. This method emphasizes personalizing exercise intensity to maximize fat oxidation.
Unlike high-intensity training, MAF highlights low to moderate exercise intensity to build endurance, reduce body fat, and improve cardiovascular health without unnecessary stress.
Monitoring heart rate offers a precise gauge of exercise intensity, keeping you in the fat-burning zone. During lower-intensity activities, fat oxidation is preferred, while higher intensities shift reliance to carbohydrates.
For older runners, maximizing fat oxidation supports mitochondrial function, enhances endurance, reduces disease risk, and minimizes bodily stress.
The MAF Heart Rate Formula
To start MAF training, a simple heart rate formula is used:
Subtract your age from 180.
Adjust the number based on health and fitness factors:
Subtract 10 if recovering from illness, taking medication, or experiencing chronic stress.
Subtract 5 if injured, frequently sick, overfat, or returning to exercise.
No adjustment if training consistently for up to 2 years.
Add 5 if training for more than 2 years without health issues and showing improvement.
The resulting number represents the highest heart rate at which fat oxidation is optimized. Training below this calculated heart rate ensures maximum aerobic benefits for you without overstressing the body.
For instance, if you're 60 years old, 180 minus 60 equals 120, which becomes your target training heart rate. Training below this heart rate (110 - 120bpm) ensures maximum aerobic benefits without overstressing the body.
Updates to the MAF Formula
Dr. Phil Maffetone just announced 2 new updates to his formula. I also show them in the section above, bolded. The new updates are:
Chronic Stress Adjustment: If experiencing chronic stress, characterized by constant pressure and overwhelm, subtract 10 beats from your calculated number as these symptoms impact training heart rate.
Over Fat Adjustment: The "over fat" designation applies if your waist size exceeds half your height, indicating metabolic distress. In this case, subtract 5 beats to your MAF heart rate for effective management.
Challenges for Older Runners
For older runners, the formula sometimes calculates a heart rate too low to maintain, making running difficult. Try and run with a heart rate of 115 bpm! Dr. Phil and other coaches suggest a variety of adjustments for age such as add 10 beats if over 60. That’s something you’ll have to play with. It's crucial to personalize this adjustment.
If over fat, prioritize being conservative with your training heart rate and don’t make the adjustment for age. Stay in the calculated fat-burning zone until your excess fat reduces. This might involve just walking, or a walk-run approach before adding those 10 beats for running training.
Introducing the Reverse MAF Approach
Not over fat? Consider my “Reverse MAF” for older runners to refine your training heart rate. This involves running at a higher heart rate initially to adapt to slower running, allowing the heart rate at this pace to decrease.
In strict Maffetone training, you keep your heart rate steady and work on increasing your running pace.
In Reverse MAF, you keep your running pace steady and work on lowering your heart rate.
To start, first determine what I call your minimum viable pace. That is the slowest possible pace you can run.
Do an extremely slow jog for one or two miles and see what your heart rate is. It may be 10 to 15 beats higher than your calculated MAF heart rate. That's ok.
Use that slow training pace for the next few weeks and you'll notice your heart rate will go down on your runs, eventually to your calculated MAF heart rate.
Then you can continue your training at or below your MAF heart rate.
Conclusion
It’s counter intuitive, but running slow will not only allow you to burn more body fat as you run, but you will also get faster! So slow down, shed body fat, and enjoy effortless, injury-free running as you age. If you have any questions, become a member and I’ll be happy to help you out!