Target Heart Rate for a marathon

Larry Brent

To train slow twitch fibers you need to run with 'less force produced by the legs' i.e. slower. This will lead to those fibers being recruited during the run and thus trained. To recruit as many of them as possible, you need to run long so that once fuel is used up in those recruited initially further ones are recruited. Added to this, once fuel is used up in slow twitch fibers fast twitch fibers will be recruited and do trained to use glycogen aerobically rather than anaerobically. So running 'slow' (with less force or aerobically might be better terms) and long is important to train as many fibers as possible (fast and slow) to be economical. Speed work on top of that will train remaining fast fibers.

But I'd say most of us neglect the slowest twitch fibers and perhaps don't train the slow and fast twitch fibers we do use to be as economical as possible and so don't reach our potential (and thus don't get near 90% hr for a marathon). It's well established though that the top Kenyans often run at 8min mile pace or slower, at the start of runs or on recovery runs. And Bekele was timed at between 8 and 9 min mile pace when warming up for a 10000m world record attempt. This is probably like us running at 10 min mile pace - how many of us ever do that?

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Larry Brent wrote: »

Marathon pace is 88-90% max HR
LT is 92-94% max HR

If you are at 92% of your LTHR, would this not be about 81% max HR give or take (i.e. 92% of 92%)? This seems quite low to me. Have you a reasoning behind this?

MHR - 193
LT - 175, using the Friel LTHR 30minute test

I could not run a marathon between 169 to 173hr as you suggest running between 88-90% MHR, it would be far too high. This is based on blowing up in London last year when i was pushing to high a HR (high 160s) and also it would have me pushing far too close to threshold for me.
I am up to 60mins @ MP for the Barca marathon coming up and 162 feels like it would be manageable over a marathon for me which is 92% of LT and 84% of MHR.

Great posts btw very informative.

Larry Brent

Maliah Tangy Plan wrote: »

I could not run a marathon between 169 to 173hr as you suggest running between 88-90% MHR, it would be far too high. This is based on blowing up in London last year when i was pushing to high a HR (high 160s) and also it would have me pushing far too close to threshold for me.
I am up to 60mins @ MP for the Barca marathon coming up and 162 feels like it would be manageable over a marathon for me which is 92% of LT and 84% of MHR.

Your 193 max HR would have Hadd believe you could actually hold 173-178 for a marathon.

84% is pretty solid for us lesser mortals though. But I think if you were able to train optimally (say you had a sole running focus) you should be able to get to the stage where you could hold 173 for a marathon. For now though your rationale for 84% / 162 bpm is sound. Best of luck with Barcelona.


You might find this interesting from Mark Allen http://www.markallenonline.com/maoArticles.aspx?AID=2

'During my 15 years of racing in the sport of triathlons I searched for those few golden tools that would allow me to maximize my training time and come up with the race results I envisioned. At the top of that list was heart rate training. It was and still is the single most potent tool an endurance athlete can use to set the intensity levels of workouts in a way that will allow for long-term athletic performance. Yes, there are other options like lactate testing, power output and pace, but all of these have certain shortcomings that make them less universally applicable than heart rate.

In our sport there are three key areas of fitness that you will be developing. These are speed, strength and endurance. Strength is fairly straightforward to do. Two days per week in the gym focusing on an overall body-strengthening program is what will do the trick. More time for a triathlete usually ends up giving diminished returns on any additional strength workout. These two key days are the ones that will give you the strength in your races to push a high power output on the bike, to accelerate when needed on the run and to sustain a high speed in the water.

Next are the focused workouts that will give you raw speed. This is perhaps the most well known part to anyone’s training. These are your interval or speed sessions where you focus on a approaching a maximal output or your top speed at some point in each of these key sessions. But again, developing speed in and of itself is a fairly simple process. It just requires putting the pain sensors in neutral and going for it for short periods of time. A total of 15-20 minutes each week in each sport of high intensity work is all it takes.

Now for the tougher part…the endurance. This is where heart rate training becomes king. Endurance is THE most important piece of a triathlete’s fitness. Why is it tough to develop? Simply put, it is challenging because it usually means an athlete will have to slow things down from their normal group training pace to effectively develop their aerobic engine and being guided by what is going on with your heart rate rather than your will to the champion of the daily training sessions with your training partners! It means swimming, cycling and running with the ego checked at the door. But for those patient enough to do just that, once the aerobic engine is built the speedwork will have a profound positive effect their fitness and allow for a longer-lasting improvement in performance than for those who blast away from the first day of training each year.

What is the solution to maximizing your endurance engine? It’s called a heart rate monitor.

Whether your goal is to win a race or just live a long healthy life, using a heart rate monitor is the single most valuable tool you can have in your training equipment arsenal. And using one in the way I am going to describe will not only help you shed those last few pounds, but will enable you to do it without either killing yourself in training or starving yourself at the dinner table.

I came from a swimming background, which in the 70’s and 80’s when I competed was a sport that lived by the “No Pain, No Gain” motto. My coach would give us workouts that were designed to push us to our limit every single day. I would go home dead, sleep as much as I could, then come back the next day for another round of punishing interval sets.

It was all I knew. So, when I entered the sport of triathlon in the early 1980’s, my mentality was to go as hard as I could at some point in every single workout I did. And to gauge how fast that might have to be, I looked at how fast the best triathletes were running at the end of the short distance races. Guys like Dave Scott, Scott Tinley and Scott Molina were able to hold close to 5 minute miles for their 10ks after swimming and biking!

So that’s what I did. Every run, even the slow ones, for at least one mile, I would try to get close to 5 minute pace. And it worked…sort of. I had some good races the first year or two, but I also suffered from minor injuries and was always feeling one run away from being too burned out to want to continue with my training.

Then came the heart rate monitor. A man named Phil Maffetone, who had done a lot of research with the monitors, contacted me. He had me try one out according to a very specific protocol. Phil said that I was doing too much anaerobic training, too much speed work, too many high end/high heart rate sessions. I was forcing my body into a chemistry that only burns carbohydrates for fuel by elevating my heart rate so high each time I went out and ran.

So he told me to go to the track, strap on the heart rate monitor, and keep my heart rate below 155 beats per minute. Maffetone told me that below this number that my body would be able to take in enough oxygen to burn fat as the main source of fuel for my muscle to move. I was going to develop my aerobic/fat burning system. What I discovered was a shock.

To keep my heart rate below 155 beats/minute, I had to slow my pace down to an 8:15 mile. That’s three minutes/mile SLOWER than I had been trying to hit in every single workout I did! My body just couldn’t utilize fat for fuel.

So, for the next four months, I did exclusively aerobic training keeping my heart rate at or below my maximum aerobic heart rate, using the monitor every single workout. And at the end of that period, my pace at the same heart rate of 155 beats/minute had improved by over a minute. And after nearly a year of doing mostly aerobic training, which by the way was much more comfortable and less taxing than the anaerobic style that I was used to, my pace at 155 beats/minute had improved to a blistering 5:20 mile.

That means that I was now able to burn fat for fuel efficiently enough to hold a pace that a year before was redlining my effort at a maximum heart rate of about 190. I had become an aerobic machine! On top of the speed benefit at lower heart rates, I was no longer feeling like I was ready for an injury the next run I went on, and I was feeling fresh after my workouts instead of being totally wasted from them.'