Friday, September 26, 2014

heart rate stuff + all ur base training are belong to us

All my life, I've been fascinated with understanding how things work. I've also been an athlete in some form or another for almost as long as I can remember, so it's probably not surprising that I have a long-running fascination with what exactly is going on in your body to make you faster/stronger/more coordinated/etc. & thus better at your sport of choice.

Running track and cross country in middle school & high school, my understanding was pretty basic (running tears down your leg muscles, which makes them grow back stronger; breathing hard tells your body you need to transport oxygen faster, so it makes more red blood cells; something something mitochondria), which satisfied me for a while. When I started participating in long-distance road races as an adult and actively trying to improve my times, though, I wanted to know more.

And WOW, what a Pandora's Box that turned out to be. As someone who never took chemistry beyond AP or biology beyond the 9th grade, I very quickly found myself out of my depth and needing to fill in some pretty serious gaps in terms of understanding the finer points of metabolism and respiration. But I still found it fascinating, and the more I learned, the more I wanted to dive even deeper.

One of my biggest "a-hah" moments was learning about the body's different pathways for fueling activity and their connection to heart rate and perceived exertion.

(Super-Quick Overview You Can Skip If This Is Not News to You--

Every cell in your body runs on a chemical called ATP, which is created by your mitochondria out of fat, glucose (blood sugar), protein, & oxygen. When your cells need energy, they can get it via a few different pathways:

  • Pathway 1: Stored ATP / creatine phosphate. We have ~2-3 seconds worth of ATP ready-to-go; after that we can very quickly turn creatine phosphate into ATP, which gets us maybe ~6-8 more seconds. This is an anaerobic pathway (ie, no oxygen required) & the system you'd use to, say, run a 100m sprint.

  • Pathway 2: Aerobic metabolism. ATP created from some combination of fat & glucose (an aerobic pathway since burning fat requires oxygen). Preferred by the body because we have basically unlimited fat stores, but slow because it's limited by how quickly your body can get oxygen from your lungs to your muscles & clear out the CO2 (respiration). Used for low-to-moderate effort activities like sleeping, chilling, walking, and--surprise!--90-99% of your distance running.

  • Pathway 3: Anaerobic glycolysis. Glycogen (stored carbs) => glucose => ATP, with lactate as a byproduct cleared out of the bloodstream by the liver. Much faster than burning fat because no oxygen is required. At aerobic effort levels, lactate is easily cleared by the liver, but harder effort => more anaerobic glycolysis => more lactate. Eventually there's a tipping point where there is more lactate than the liver can keep up with (lactate threshold or LT). At that point you're in the anaerobic zone, & if you stay at that effort level, you'll eventually reach a point where burning muscles, labored breathing, etc., will force you to slow down.

LT is usually given as a percentage of max heart rate. There are field protocols for estimating it, but to know it exactly requires lab testing. Very fit endurance athletes have a high LT, because they can stay in the aerobic zone (ie, not relying too much on glycolysis & also clearing lactate effectively) at quite high heart rates; less fit people have a low LT, meaning their heart rate can't get very high before they're in the anaerobic zone.)

Of course I know that one of the most common Sins of the Recreational Distance Runner is doing easy runs too fast (ie, even if you're not technically running in the anaerobic zone, running hard enough that you're letting glycolysis do too much of the work & letting the aerobic/fat-burning system coast). While I don't think I've been super egregious about this, I know I've been guilty of some of it in the last couple of years & let those aerobic systems atrophy somewhat. And it just kind of seems like a waste to train for another marathon without investing some serious time in fixing that first.



I feel you, Captain; I made that exact face at first.

I don't know yet when my next marathon will be, but I'm in no rush; I might as well take the time to finally do it right. So for the next couple of months at least, I'm planning to do nothing but sloooooooow, easy, low heart rate runs and maybe two days a week of a few super short (ie, ~30 seconds) hill or bike sprints (more on that later).

I've also decided to go back to wearing a heart rate monitor every run, for a couple of reasons.

First, I suck at running slow and am really really good at talking myself into believing that "This pace is *totally* super easy, NO REALLY." Numbers (mostly) don't lie, so having them right in front of me should force me to be more disciplined about *actually* taking it easy.

Second, having a record of the numbers makes it easier to see improvement. Back in 2011 I ran with a monitor almost all the time, and over a long enough time period, you can actually see your aerobic fitness improving in the numbers, which is pretty cool.

18 weeks of HRM data from easy runs in 2011. Shit works.

But what's that you say? Heart rate monitors suck, you say? What ofthe unsightly blood & mangled skin in the chest area, you say?

I'm glad you asked, because that brings us to point three. I've finally jumped on the Mio bandwagon thanks to Jen & Kimra, which, believe me, is the only way I could talk myself into wearing a monitor every day.

(I am not kidding that I have what I'm pretty sure are permanent scars on my chest from the days when I wore the chest strap every day. Ick.)

I'd actually intended to use my heart rate monitor this whole past summer, which is why I got the Garmin soft strap back in May. Alas, just a few runs were enough to remind me why I gave that shit up the first time and question whether there is a strap in the world soft enough to make any noticeable difference.

That time in 2011 when the chafing was so bad
I was augmenting band-aids with duct tape. Screw that.

I've only been using the Mio for a couple of weeks, so I'll try to post a review sometime in October; so far, things are promising.

Now. Before I say anything else about heart rate training: I have educated myself enough to know that there's approximately a metric tonne of bullshit out there about heart rates and heart rate zones and how they relate to exercise & endurance training. Gird your loins should you start googling about it. Plenty of ink has been already spilled on this topic, so I will not rehash all that here except to say:

  • I'm not a doctor, but I have a heart condition so I have had a lot of conversations with heart doctors about heart rates and exercise.
  • I've had my max heart rate & tons of other heart-related stuff tested, multiple times, in a lab, by actual scientists & doctors, so I'm not guessing about my own numbers.
  • If you don't know your max heart rate, it's difficult to do any meaningful sort of heart rate training.
  • Your max heart rate is not 220 minus your age. If I only I could cast this abomination of a statement into the Fiery Volcano of Hateful, Propagated Lies for all time and never have to hear or read it again. Don't fall for it! Alas, MHR is a biomarker that has so far defied meaningful prediction by any formula--there's just too much variation that isn't correlated with anything measurable.

So. I really do want to spend a lot of time putting in lots of miles at a super easy effort. While I believe whole-heartedly in the spirit of Maffetone, I just can't really do it full-on; I tried back in '10-'11, & while I know everyone says "OMG THERE IS NO WAY I CAN TRAIN THAT SLOWLY," I'm pretty sure I had a whole other level of "this is never going to happen" going on, since 1) Maffetone uses a formula that doesn't take max heart rate into account (!) and 2) I have an insanely high max heart rate. (Not kidding, my GP thought I was making it up and/or stupid until I showed her the lab report.)

The glorious Phil Maffetone. You didn't know he was also a singer-songwriter, did you?

Like really. Supposedly my "MAF number" (the heart rate you should be shooting for on your easy runs) is around 142ish, which let's be clear, is brisk walking for me. Walking uphill it's like 150. I mean I may have some work to do on my aerobic system, but I just refuse to believe it's THAT bad.

These last couple of weeks with the Mio, I've faithfully slowed my easy runs, way, waaaaay down, from the 8:00-8:30ish range to around two full minutes slower. Although it varies some depending on the temperature, so far I've been able to average in the 150s in terms of heart rate for most of my runs, as opposed to the usual ~175-180ish (the spirit of Maffetone being that, over time, you should find yourself speeding up while maintaining the same low heart rate). I think that's just going to have to be good enough.


(No but really, the resemblance is kind of creepy, right?)

Right now I have a loose plan to do only that & the occasional short-burst intervals for the next two months, then add in one progressively longer weekly marathon-pace run for the next two months after that. I love love love data & statistics, so I'll be sure to record everything & report back.


  1. I love the "All your base" references and also the Phil Maffetone pics. I think you already know how I feel about this. Looking forward to seeing all of your data! (and glad I'm not going to be the only one nerding out about numbers on my blog)

  2. Firstly...Phil Maffetone, I had no idea what a Dude he is!

    Secondly...this is spooky because I read this post as I came in from a frankly very disappointing run. I've been thinking for a while that I am overdoing ALL my runs, I don't have any easy runs and I think my legs are just cooked as a result and I am getting slower. I've just written a long post about it. So this whole 'train slow, race fast' thing sounds very appealing! I've just ordered the 80/20 Matt Fitzgerald book so i'll see what that tells me. But i do think I'm guilty of over-running and I'm paying the price!!

    I'm not yet sold into HRM training as such (although the Mio is sexy enough to tempt me even without Jen's excellent review) but I can see me jumping on this 'train slowly' bandwagon!

    1. I figure it can't possibly hurt!

    2. (Also, I'll be interested to hear what you think of 80/20, given my deep & abiding love of all things Matt Fitzgerald.)

  3. Oh That Phil! I am a MAFer, and yep, it can kinda suck. But it has worked well for me and several months in, I can feel that I am building a very strong engine. That said, by years end I am going to add in a bit of speedwork, but by then I will have almost six months at MAF so I will have a pretty nice base, even if not my absolute best base. Good luck with your new approach.

    1. Thanks! I'm very interested to see how it all works out. :)

  4. OK, so the early version of the Mio beeped constantly if you were out of your prescribed HR zone, which I couldn't figure out how to get it to stop. And, it didn't have the basic functions of a regular running watch -- lap times, splits, chrono. And you couldn't see both the HR and time and the same time. It was really annoying. I take it the new model is better?

    1. OK so spoiler, there are two different Mios. There's the one with the screen, which to me seems like the amateur version you'd get if you've never run with any kind of tech watch & just wanted info on your heart rate, which sounds more like the early version you're describing. They now have a version called the Mio Link, which works just like a chest strap, except you wear it on your wrist. (Ie, it works with the whole ANT+ interface & will link up with whatever GPS device/phone app you're running with), so you get all the data from your device of choice the way you would with a chest strap, & the wrist piece itself just has one flashing light that tells you how much battery it has.

    2. (The down side being the dorky two-wrist-devices look.)

  5. Throwing this out there, and rather off topic, but...could you have a congenital heart defect leading to high max HR? It's possible, and you know...better safe than sorry.
    Ugh, I hate how medical I've gotten.

    1. Heh, no, fair question. It was the first thing I asked the cardiologist about after I had my heart rate tested, but he assured me that although my MHR is quite high, it's not like inhumanly high, and there was no reason to think it was connected to anything else, and everything else about my heart looks perfectly healthy for running (ie, I've been tested for all the random stuff that tends to cause people to drop dead in marathons, & thankfully I don't have any of that).

  6. I LOL'ed at your resurrection of a meme from, like, 1998, and for a second was wondering if this had turned into a Harry Potter fanfiction blog? But no, I checked out Phil Maffetone's website. Dude is a trip. Looking forward to your reports (all your data are belong to us?).

    I presume you also know best whether you have some sort of congenital arrhythmia that might make certain things risky... anyway good luck with the new training regime!

    1. Seriously. Phil Maffetone is like my favorite person of the week.

      Like I said above, fair question. The arrhythmia stuff was the first thing I asked the cardiologist about after I had my heart rate tested, but he assured me that although my MHR is quite high, it's not like inhumanly high, and there was no reason to think it was connected to anything else, and everything else about my heart looks perfectly healthy for running (ie, I've been tested for all the random stuff that tends to cause people to drop dead in marathons, & thankfully I don't have any of that).

  7. I've known for some time that the 220- age thing was rubbish. I'm over fifty now and can get up to the 190s in speed training. So that means that either the formula was out or I've been lying about my age. But what woman in their right mind would pretend that she's 50 if she's only 30?

  8. I've always had a high max heart rate. I had stress tests in high school and college as an athlete and always measured in the "high normal" range. No one freaked out. (Just like my body fat (low athlete normal) and BMI (high) both measured in ranges that weren't ideal, but seemed to work for me). What I've noticed is that the formulas definitely decline more strongly than someone with my physiology would find to be normal. A few years ago, I was wearing a HRM for all runs and hit 208 on a few hills at the beginning of some of my runs in my mid 30s. My GP was not concerned. At the end of that training cycle, my average training HR had dropped significantly, and I run an almost marathon PR. The take-home for me was my "max" is so far outside of the norm (and has been since early adult-hood) that most of the formulas don't work for me. In unrelated news, I've been enjoying a 6+ month super low effort training cycle. Nothing but jogging/easy running to audiobooks for most of my runs. It's wonderful!