The Three Pillars of Marathon Training

26.2 miles. 

It’s a distance most people don’t want to drive, let alone run. The marathon is, in my opinion, the first true running test.

Whether it’s a 5k, 10k, or half-marathon, I’m not saying these distances don’t count, but for the most part you can complete them without too much prior training if you’re really set on it.

That’s just not true for the full marathon. If you step up to that start line without putting in enough actual and effective training, that distance will expose you. The marathon is unforgiving, and it will humble you and expose the work you didn’t put in.

But it’s also a distance that can help us realize we are so much stronger than we give ourselves credit for. It’s a distance that seems impossible to most of the world until we prove to ourselves it’s not.

There is a saying in the running world that, yes, a marathon is extremely difficult. But the most challenging part of marathon training is not the race, but the training itself. I am now in my 3rd marathon block, and this has rung true in every single one of my training blocks so far.

While the training itself is so incredibly challenging — the early mornings, seemingly scheduling your entire life around training runs, and continuing to show up week after week — all of the training is 100% worth it for the feeling when we finally cross the finish line, especially in a time we’ve never hit before.

So let’s talk about the three pillars of the marathon training block and how to use them to PR your next race:

Pillar 1: The Tempo Run

The tempo run is often called the “bread and butter” of marathon training — and for good reason. It’s designed to run at a comfortably hard effort, usually just below your lactate threshold (the pace you could hold for about an hour).

You should feel challenged, but not like you’re sprinting. Think of it as learning to run fast without falling apart.

The key benefit of the tempo run is efficiency. At this effort, your body learns to clear lactic acid more effectively, which means you can sustain faster paces for longer periods. 

It directly translates to making your marathon goal pace feel more comfortable — because your system has been trained to handle the stress.

Beyond the physical, tempo runs sharpen your mental toughness. They put you in that “uncomfortable but controlled” zone, teaching you how to stay composed under pressure. On race day, when your body starts to fight back, you’ll already be familiar with that feeling — and ready to push through it.

Pillar 2: The Easy Run

Easy runs are the unsung heroes of marathon training. They’re done at a relaxed, conversational pace where you can breathe and talk without strain. While they might feel “too easy,” they are the foundation of your training — providing balance to the harder sessions.

Physiologically, easy runs are where the magic happens. They strengthen your aerobic base, improve blood flow, and build more mitochondria in your muscles (the engines that power endurance).

Simply put: the more easy miles you run, the more efficient your body becomes at using oxygen — the single biggest predictor of marathon performance.

Easy runs are also your best defense against injury and burnout. By keeping intensity low, they allow your body to recover while still getting meaningful mileage. 

They give you the volume you need without digging a hole you can’t climb out of. When you master running easy, you unlock consistency — the most important ingredient in marathon training.

Pillar 3: The Long Run

The long run is the crown jewel of marathon prep. Typically the longest run of your week, it’s usually done at an easy pace — sometimes with sections at marathon pace. It’s not just about distance; it’s about building the stamina and durability to handle 26.2 miles.

From a physiological standpoint, long runs train your body to become more fuel-efficient. They improve fat oxidation (burning fat for fuel), strengthen muscles and connective tissues, and condition your legs for the hours of pounding they’ll face on race day.

They also help you test and refine your nutrition and hydration strategy before the big day. A good rule of thumb: never try anything for the first time on race day. Your pre- and intra-fueling should be the same and already tested in your long training runs.

Equally important is the mental side. Long runs teach patience, discipline, and resilience. They simulate the grind of the marathon and prepare you for the moment when things get tough late in the race. If you can master the long run in training, you’ll carry that confidence with you to the start line — and across the finish.

These are the three pillars that make marathon training harder than the actual marathon distance itself, but they are also where PRs are truly built. 

They develop our speed, build our foundation, and create the physical and mental endurance needed to not only complete but crush that PR in the marathon.

Happy Marathon Season!

Sean

GTY