Not Progressing with MAF Low Heart Rate Training

Several times a week I read comments in our Extramilest Facebook Group about runners starting out with MAF low heart rate training and their MAF pace is not improving over time.

There are often a variety of causes, in many cases it’s not just related to the running activities, but also to additional stress factors and / or nutrition.

Although many athletes know the basic fundamentals of low heart rate training, the implementation and execution can make or break progress.

In today’s post I want to address a situation from a specific runner who is not progressing yet and dive deep into the details of what could be causing no progress. Several of these comments mentioned by her, apply to other runners as well. 

To explain to those not aware, a MAF – test is a great test to measure your current fitness level and how you are progressing over time. Developed by Dr. Phil Maffetone, this test is simple, ideally performed at a running track or flat course: you warm up for 15 – 20 minutes, then you run 5 miles (or 8km) at your Max Aerobic HR (MAF = calculated using the 180 formula) and you measure your splits per mile or km. 

This week I read a post by a female runner who posted the following her MAF test times:

• MAF Test Month 1 = 12:59 min / mile (on May 16, 2019)
  
• MAF Test Month 2 = 13:26 min / mile (on June 20, 2019)  
  

She wrote the following message: 

“So had a very disappointing MAF test run today. More then 25 seconds slower per mile then 1 month ago.Is there anyone else out there who had the same thing happen? I am struggling to figure out what is going wrong.I have been running 25-30 miles a week, longest run between 2 and 2 1/2 hours. I find it very difficult to stay below my maf heart rate and am constantly slowing down.I have been eating low carb for over 2 years now and am well fat adapted. I do most runs fasted.
My sleep is not the greatest (I have a kid with sleep issues) but this hasn’t really changed. Stress otherwise is low.It was 10-15 degrees hotter on my second run, which could be a factor.Could this be overtraining?I am running a lot more mileage then before but am not doing any of the lifting I was doing before.I haven’t given up cycling and went on a MTB ride the day before – 2 hours, 18% anaerobic. Is this the problem?I had noticed my pace increasing for the first few weeks running slowly but lately things have reversed.What should I do?Persist? Drop mileage or target heart rate?Are there some people for whom this method just doesn’t work?!?”

Here is my response to her, also posted in our Extramilest Facebook Group.  

Thanks for sharing your experiences. Becoming slower in a MAF test surely can feel disappointing at first. Several great insights already mentioned by others in the comments. 

A reduction in MAF pace can be caused by several different factors. A few of my observations and thoughts: 

• This was your first and second MAF test, it sounds like you’re just getting started with low heart rate training. 

• “25-30 miles a week, longest run between 2 and 2 1/2 hours” If you run these miles at let’s say 13 min / miles, that’s 5 hours 25 to 6 hours 30 minutes of running per week. Not sure how your’ve build up your training volume over time, but 5 hours 25 minutes to 6 hours 30 minutes of running a week + 2 hours mountain biking is a significant amount of training volume. I’d suggest you don’t increase your training volume week over week with more than 10% max (often less) and take a step back week after 3 weeks. 

• Roughly calculated, your longest run of 2 to 2.5 hours is 31% to 46% of your weekly training volume. To limit the stress on your body, I’d really aim not to go over 25-30% of weekly training volume on your long run. At these early stages of getting into low HR training, I would lower your overall volume and stick to workouts of 40 to 60 minutes. No need at this stage to go longer. If you do this up to 4 days a week, with aerobic bike rides or walks / hikes on 1 or 2 other days and 1 or 2 full rest days. 

• During the base building period, the goal is to keep your heart rate aerobic. You mentioned it is very difficult to stay below MAF HR. I can understand this is, because around 13 min / mile is the transition point for most athletes from running to walking. It might be that your HR is still going over the MAF HR too frequently, resulting in an anaerobic response. Setting a HR alarm a few beats below MAF could help with this. Taking walk breaks is totally fine, many athletes have to do this at the beginning of their low HR journey, embrace this, try not to get frustrated about this. A positive mindset impacts your nervous system positively as well. 

• You went on a 2 hours of mountain biking with 18% anaerobic. That’s 21 minutes of higher heart rate workout. If you’re not noticing progress in your MAF pace, I’d try to limit the anaerobic workouts as much as possible, especially when you are not progressing with MAF.

• Congrats on being a mom, that can bring a lot of joy. As a dad I can emphasize for your kid having sleep issues, that can be very challenging! Not only does it result in poor sleep for you, it does increase your stress levels as well as you are concerned about your child. Nothing you can do here, other than making sure you get enough rest and time to recover. Remember, training = stress + recovery. If that means having to take a nap in the afternoon vs working out, that might do more good for you. 

• Part of this journey is to really learn how to listen to the signals from your body. If you feel exhausted from not getting enough sleep, listen to your body and sleep more. As an example, the past several weeks I’ve been busy with family and work projects, I opt out of several workouts a week, in order to make sure I get enough sleep. 

• “I have been eating low carb for over 2 years now and am well fat adapted” That’s great you are low carb. Here are some things to consider, how about the other elements of your nutrition, are you eating enough fats, vegetables, protein, etc? Are you taking in enough calories? Can you be too low on carbs? Whenever I ate too little carbs, my performance went out the window and my MAF pace slowed down significantly. 

• “I do most runs fasted.” I’ve experimented with fasted runs vs non fasted runs. Although I understand some athletes like fasted runs to teach their body to use fat as fuel source, fasted runs in my personal experience, have slowed down my MAF test pace. You don’t need to run your runs fasted to improve your MAF time. Eat breakfast, go for a MAF test and see if you can notice a difference. 

• “It was 10-15 degrees hotter on my second run, which could be a factor.” Weather stress is real and this temperature difference is absolutely noticeable aerobically. Personally I run my MAF tests early in the morning, so the temperatures are relative low + you don’t have the stresses from a full day when you do a MAF test in the evening. 

• In many cases, your body has to destress first from a long time of higher HR work outs, so several athletes will first go backwards in their MAF pace, before they start to improve. Progress takes time, for some athletes this happens in just a month time, others might not progress for 3 to 6+ months. 

• “What should I do? Persist? Drop mileage or target heart rate?” I’m not sure how you’ve calculated your MAF HR, could be that you’ve even chosen a number that is too high for you. Whenever in doubt, pick the lower number, using this article: https://philmaffetone.com/180-formula/

• “Are there some people for whom this method just doesn’t work?!?” This approach of lowering intensity of your workouts to build an aerobic base, improving nutrition and limiting stress is beneficial for all athletes. The 180-formula is accurate for most people, however for most accuracy a medical lab test provides more precision. That being said, given all the factors described earlier, I feel there are many opportunities to improve without doing a lab test. 

Consistency, patience and a positive mindset are absolutely key in this process. It’s about time on feet in the right HR zone, not about your pace or distance covered. Trust that progress will follow. Become mindful of the sounds around you, the footsteps on the ground, the wind, the sun, all the elements of being outside. Try to enjoy being outside in nature. 

Here are some additional posts you might find helpful:

• Overcoming frustrations with MAF low heart rate training
• 7 reasons why some athletes are not making progress with MAF training and what to do about it
• Dr Phil Maffetone interview on heart rate training, nutrition and recovery
• Dr Phil Maffetone on MAF Training with Low Heart Rate, Low Carb, Intervals, Ketosis, Fasting & more

Hope these things help. Wishing you all the best on your journey, please keep us posted how things go. 

If you, or anyone else here reading this has any questions about this, let us know in the Extramilest Facebook Group here.