Polarised Training for Endurance Athletes

I see a lot of recreational to high-level endurance athletes training for marathons, triathalons, cycling races etc getting their training wrong. They just want to run faster, further and sustain a higher heart rate for longer. Most will have a few routes they do, for example a 2-mile running route that they do every week and each week they just want to beat their time and if they do they are happy.  This kind of training you’ll show improvements at first but you’ll quickly plateau. 

They are training in no-mans land in the middle of the volume intensity curve, so fairly hard. So although this leaves you with a feeling that you have worked hard, it causes too much stress for the little rewards(1). This means you have worked hard enough to need to recover, but not hard enough to produce any noticeable adaptations. My lecturer on my masters Chris Edmundson used to say training fairly hard makes you fairly good. And he’s right, no-one wants to be fairly good, everyone wants to be the best they can be. 

We need to consider what how the elites train. They do a thing called polarised training, so training should be very easy or very hard, and they roughly split their volume 80% easy 20% hard. It is common for low intensity sessions to be performed harder than prescribed and high intensity sessions to be performed at a lower intensity, if you can stick to the polarised model it offers variety, making training feel less monotone.

Low intensity sessions should be performed around 65-75% maximum heart rate (MHR), so feels like a difficulty of about 4/10. And these sessions should last 2 – 5 hours. This is going to produce many adaptations including improved fat metabolism, improved lactate removal, increased glycogen storage and increased muscle capillary density(2&3). 

The high intensity sessions are often done wrong as well, people will do 30s – 2 min efforts. Really a protocol of 6 sets of 4 mins running at around 90% MHR with 2 min rest would be awesome, however depending on your level of training you might need to work up to doing 6 sets. Then when you can achieve this, instead of trying to do your 4 minutes efforts at a higher heart rate, maintain the 90% MHR and do an extra set. 

Just remember elite athletes are freaks! Normally they are at a genetic advantage, but they are always unbelievably disciplined and industrious. Even on their easy days they would be working on something, for example their breathing technique. I used to work with an athlete who trained so hard on these days that he would have to ‘pysch’ himself up for at least 48 hours prior. 


1 – Matheny, F. (1995). Stop training in ‘no man’s land’. Bicycling, 36(10), 90.

2 - Ingjer, F. (1979). Effects of endurance training on muscle fibre ATP‐ase activity, capillary supply and mitochondrial content in man. The Journal of Physiology294(1), 419-432.

3 - Schwartz, R. S., Shuman, W. P., Larson, V., Cain, K. C., Fellingham, G. W., Beard, J. C., ... & Abrass, I. B. (1991). The effect of intensive endurance exercise training on body fat distribution in young and older men. Metabolism-Clinical and Experimental40(5), 545-551.

Daniel Morgan