For some time now I’ve been aiming to do my endurance training at my MAF heart rate. MAF stands for Maximum Aerobic Function, and it’s the heart rate where you’re producing the maximum output without having to use anaerobic systems. Although the MAF formula just produces an estimate, there’s quite a bit of data to back it up.

If you do almost all your training at MAF, you’ll get better (run faster) at that heart rate. The idea is that you first do that, and only when your performance plateaus do you need to start doing any sort of speed work (and then not much of it).

As I say, for some time I’ve been aiming to train at my MAF heart rate, but it’s a low enough level of intensity that I’ve persistently had trouble not running too fast. I have a heart rate monitor, but it’s not very useful during a run, because my heart rate is displayed on my phone, and I don’t want to run around carrying my phone where I can see the screen. The upshot has been that I’ve inadvertently done a great deal of my training somewhat above my MAF heart rate, which rather defeats the purpose.

To get a better grip on my MAF training, I finally broke down and bought another heart rate monitor, which displays my heart rate on my wrist so I can check it while I’m running. It also has an alert function, so I can set it to vibrate if my heart rate goes above some value. After looking around a bit, I settled on the Mi Band 4 (which is available for cheap because the Mi Band 5 is now out). It does the thing I want well enough. (It also does a bunch of other stuff that I don’t care about, and some things that I do care about (sleep tracking), but that I do some other way, such as with my Oura ring.)

After a shakedown run a few days ago, where I spent a lot of time trying to figure out how to use the device the way I wanted, today I went out for a run where I tried to use it for some proper MAF training, and I think I was very successful. I probably only spent two or three minutes (out of a 51-minute run) with my heart rate above my target.

This very easy run was nice and gentle. Sitting here at my computer maybe an hour after I got home, my heart rate is already back down to just 64 bpm, which amounts to a surprisingly complete recover. After a run only a little bit faster, I’d expect to see my heart rate stuck in the 70s for several hours.

Now to see if regular training this way produces the speed gains it is reputed to.

I’ve resisted low-carb eating for a long time, even as the evidence has increased that high-carb diets are terrible for us.

Via Christopher McDougal’s book Natural Born Heroes, I discovered Phil Maffetone and his two-week test, which caught my eye.

I’m generally very healthy and feel great, but I do have a few health issues—and there seems to be at least some evidence that a low-carb diet might help all of them. The point of the two-week test is to test exactly that: If you go very low-carb, does it make things better? If not, then you’re done—excess carbs are probably not your problem. If it does make things better, then you follow up the two-week test by gradually experimenting with adding carbs from various sources in various amounts, and figure out how much (and which kinds) of carbs you can consume without problem.

The things I’m hoping a low-carb diet might help are these:

  1. Allergies. Over the last twenty years I’ve gone from claiming that I don’t have allergies, to admitting that I get sniffles for a couple of weeks in the spring and the fall, to needing to take both Claritin and Nasacort daily. There’s some reason to believe that a low-carb diet might reduce inflammation. If true, that might ease my allergy symptoms (besides improving my general health), and might mean that I could eliminate those drugs, or perhaps just reduce them from constant to occasional.
  2. High blood pressure. My blood pressure is well-controlled with lisinopril, and I’ve been able to cut the dose since I’ve lost some weight these past 5 years, but it’s another drug that I take daily. It seems very likely that a low-carb diet will reduce my blood pressure, very possibly eliminating the need for this drug as well.
  3. High blood sugar. Back in 2003, I got a high blood glucose reading, and a stern talking-to about pre-diabetes. I responded by sharply reducing my consumption of soft drinks. That brought my blood glucose down to 91 in just six months. The past two years, though, my glucose has been ever-so-slightly high again. It’s not at a scary level, but I don’t like it even a little bit high. Undoubtedly, a low-carb diet will improve this.
  4. Weight loss. My weight is in the normal range, and has been since 2014. Further weight loss probably has no health benefit. Still, purely for aesthetic reasons, I’d be pleased to lose another few pounds. A low-carb diet will probably produce this result as well.

The main purpose of this post has simply been to get my thinking in order regarding what I’m hoping to accomplish. I have little doubt that a low-carb diet will produce the latter two improvements, but those issues could be dealt with easily enough through less drastic means. I have much less confidence about the former two, but improving those things would be a big deal for me—big enough to undertake the two-week test (at least), and maybe to change the way I eat going forward.