Endurance training. Less is More.

Endurance athletes such as competitive long-distance runners, spend around 80% of their time on low intensity training. They are ‘deliberately holding back’ and not giving it their all ‘at a pace so easy that it looks like they are not doing very much at all.’ What they are doing though, is ‘building up the miles’ and this in turn builds up stamina. The other 20% of their training time is spent at high intensity, going full throttle: ‘superhuman bursts of speed and power’.

Whether the elite is training 20 or 40 hours a week, the training broadly follows this 80/20 split,” says Dr Stephen Seiler, a renowned exercise psychologist at the University of Agder in Norway. Seiler observed the training routines of elite athletes and found that very little time was spent in the space between the low intensity (below the first lactate threshold) and very high intensity (above the second lactate threshold) -- in other words, they were practising ‘polarized training’.

Broadly speaking, there are 3 intensity zones. At low intensity breathing is comfortable, muscles are not worked too hard, and it feels like it’s a relatively easy workout (for the athletes of course, not for the unfit). This effort level could be maintained for hours and what it does is, it allows the body to ‘optimize the mechanisms of fat metabolism which improves oxygen transport to your muscles’ thereby improving energy levels.

Also, low intensity exercise results in your body producing more mitochondria; you may know from Biology that these are found in human cells and it's where respiration and energy production takes place. So, technically the low intensity exercise you do, can give your energy levels a boost. That’s not to say you can simply go for a stroll in the park - it must be proper exercise. (Of course, fresh air is always good for you as is any exercise – however gentle).

Medium intensity training is reasonably strenuous but allows you to still speak in short sentences; on the other hand, at high intensity, you would be breathing hard after a few minutes, unable to talk much and you would feel a burning sensation in your legs (due to the build-up of lactate acid due to exertion).

It’s not just runners who benefit from this kind of high/low interval work, but also competitive cross-country skiers, rowers, cyclists and triathletes too. Researchers have found that using this formula when training for stamina-based sports, improves endurance and reduces the risk of injury, plus performance at competitions is better. When it comes to building endurance, less really is more.

For the rest of us, who are not super-human and who keep fit but don’t aim for demanding, endurance-testing races, we can practise HIIT (high intensity interval training) that has become very popular – short bursts of intense exercise with rest periods in between.

Suggested Links:

HIIT (High Intensity Interval Training) | The Nutrition Source | Harvard T.H. Chan School of Public Health

What is 80/20 training? (runnersworld.com)

How Pro Endurance Athletes Became The Hardest-Working Creators on the Internet | GQ

When Lower Intensity Leads to Higher Results (hbr.org)

Polarised training for runners | World's Marathons (worldsmarathons.com)

2022 - Stephen Seiler - Science & Cycling (science-cycling.org)