Why is the fundamental endurance pace key to progress in running?

Before talking about the fundamental endurance pace, let's go back a long way in time.

We exist because our very distant ancestors developed the ability as hunters to run long distances. This enabled them to hunt in groups animals that were faster than them over short distances but less enduring than humans over very long distances.

The scientific community of evolutionary biologists, paleoanthropologists and neuroscientists all agree that our bodies and brains evolved to run long distances so that, thousands of years ago, we could slowly or patiently hunt animals.

In other words, we are genetically programmed to run (which was critical for the survival of our species).

The extraordinary thing is that even if a human being has never really run in his life or has stopped running for a long time, his body is programmed to adapt to a progressive training load and to modify and transform itself. It will become stronger, toned, and slimmer as training progresses. One thing though that we need to remind ourselves: we need to train very gradually and always have enough time to recover to avoid injury.

To return now to the fundamental endurance pace, this is the one we can maintain for hours (while refueling and hydrating regularly).

Why is fundamental endurance important and what is it used for?

In running, as in any other endurance sport, the fundamental endurance pace is the basis on which we can build our training and measure our progress.

It's also the pace at which we need to run most often: between 70 and 80% of our weekly training schedule.

Why is that?

Because fundamental endurance pace is a running pace that contributes greatly not to increasing the amount of oxygen we inhale when we run, but to improving the way we use that oxygen. Fundamental endurance strengthens the heart. Strengthening the heart means adapting it to the effort involved by increasing the blood flow it can process with each beat. The more we progress, the stronger our heart becomes and the less it will need to 'push' to deliver the same quantity of oxygenated blood to the rest of the body, particularly the muscles, which will be able to produce more energy thanks to the aerobic system. Running at a slow pace also means developing the network of blood capillaries inside the muscles, making them more efficient.

How do you calculate your fundamental endurance pace and how long should you run at this pace?

There are two distinct methods for calculating your fundamental endurance pace, the pace you can maintain over a long period.

The first method involves calculating it based on our Maximum Heart Rate (MHR). In general, our fundamental pace should be between 65 and 75% of our MHR. If a runner has an MHR of 200, for example (to make the calculations easier), her fundamental endurance pace is the one where her heart rate is between 130 and 150 beats per minute.

The second method involves calculating our Maximum Aerobic Speed or VO2max, i.e. the pace at which we reach our maximum oxygen consumption. In this second case, our fundamental pace should be between 60 and 65% of your MAS. For example, if a runner has an MAS of 15 km/h, his fundamental pace should be between 9 and 9.8 km/h.

When training, it is advisable to run between 70 and 80% of the time at a fundamental endurance pace. If you run for 4 hours a week, for example, and you have a MAS of 15km/h, as in the example above, this means that you should run at a pace just under 10km/h for around 3 hours out of a total of 4 hours a week.

One thing is almost certain, you're going to find it extremely difficult to follow this advice and run at this fundamental endurance pace around three-quarters of the time during your training sessions. Why ? Because, as runners, we're often driven by a strong desire to progress, to improve our time over key distances such as the 10K, the half-marathon or the full marathon. And running relatively slowly for a long time seems to us not only counter-intuitive but also counter-productive, when in fact the opposite is true. Running too often and for too long at sustained paces risks leading us straight to injury or fatigue, rather than towards optimal performance.

So, try hard to resist the call of speed. Run about three-quarters of the time in training at your fundamental endurance pace (even if it seems slow and easy to maintain). You'll have plenty of time during your interval training sessions to push yourself and put in intense effort during demanding interval sessions that aren't easy to achieve.

In conclusion, it's highly beneficial to run at a fundamental endurance pace around three-quarters of the time during your training sessions. It's one of the keys to building strength, making progress, avoiding injury and, above all, ensuring that you enjoy the benefits and pleasure of running for as long as possible.