The 80:20 rule for endurance running

Have you noticed that so many fitness ideas quote some sort of 80:20 rule? If you want a six pack, it’s 80% diet, 20% exercise. Being able to train harder or stick to your diet, oh it’s 80% in your mind. The truth is it’s often a cliché in the same way we use “9 out of 10 times” when trying to make any argument in life where we have a gut feeling but no facts.

There’s a particular Athlete and Endurance expert of sorts who’s very popular and as a popular figure, his opinion holds a lot of sway whether 100% accurate or not. We all make mistakes I’ll admit, but when your whole image and brand is around 80:20, you’re not likely to shout from the rooftops when new research emerges suggesting it’s not quite that simple.

The popular “celebrities” in fitness aren’t the ones in labs and metabolic wards doing months of testing and data analysis, and they’re rarely the ones heading up teams of statisticians and experts in the field doing a meta-analysis of all the existing data on a given topic. They just write about a topic in a way that appeals to people, often by oversimplifying things greatly and giving it some sort of system that they can monetise via books, apps and online templated programmes. It’s a job and will help a certain number of people, but the person who benefits most is the author.

The commonly cited rule in the context of endurance training, is that 80% of your training should be performed at a low intensity, with 20% at a moderate to high intensity. This will often yield good results for people, but it isn’t backed up by a lot of the more recent research in the area.

During a course I was on via the University of Kent in 2019, I saw data that shows better results come from 75-80% low intensity, 5-10% moderate intensity and between 15-20% high intensity training. This might not seem like an enormous shift, but considering that it clearly differentiates between the moderate and high intensity work, there’s a substantial change.

80:20 says you would work for 4hrs 48mins at low intensity, with just 1hr 12mins at moderate to high intensity.

The newer way of thinking would give you 4hrs 30-4hrs 48mins low intensity, 18-36mins moderate intensity and 54mins – 1hr 12 mins at high intensity.

Which do you think will yield more physical fitness as well as mental fortitude?

Which do you think will keep you running well in your half marathons and 10k races during training for the marathon and in the weeks after?

Exactly!