The Mileage Question Every Marathoner Eventually Faces

Mileage Matters — But It’s Not the Whole Story

If you spend any time in running forums or comment sections, you’ll see a new debate has popped up recently:

“Does running more miles actually make you faster?”

It’s a question I’ve wrestled with myself over the years — first as a marathoner trying to figure out what actually works, and now as a running coach helping other runners do the same.

Some people insist mileage is everything.

Others say mileage is overrated and you can get just as fast running less.

The truth — like most things in running — is a little more nuanced.

Personally, I’ve seen both sides of it in my own training.

My marathon PR came after the highest-mileage training cycle I’ve ever done.

I followed one of the plans from Advanced Marathoning by Pete Pfitzinger — the kind of plan that doesn’t ease you gently into volume.

Two months before the race I was averaging about 61 miles per week.

The month before the race I averaged 63 miles per week, with a couple 70-mile weeks mixed in.

It worked.

But I’d be lying if I said it was comfortable.

Weekly 15-mile runs on Wednesdays, 10 miles on Fridays, and then a long run on Sunday meant I spent a lot of that training block feeling tired.

It worked. But I felt worked.

That’s the frustrating truth about marathon training: the training block that produces your best race is often the one that feels the hardest while you're in the middle of it.

That’s the part of the mileage conversation that sometimes gets glossed over.

Higher mileage absolutely builds fitness.

But it can also be hard.

There’s a reason so many successful marathon plans gradually increase volume.

As exercise physiologist and legendary coach Jack Daniels has pointed out for decades, the single biggest driver of endurance performance is simply time spent running aerobically.

In other words, the marathon rewards time on your feet more than almost anything else.

More running creates aerobic adaptations that directly affect endurance:

• more mitochondria in muscle cells
• increased capillary density
• improved fat utilization
• greater stroke volume from the heart

In simple terms: your aerobic engine gets bigger.

That’s why runners who can safely handle higher mileage often see improvements in the marathon.

I saw it myself.

That tough Pfitzinger training cycle? Yeah, it produced my marathon PR.

Last year I ran the Mount Desert Island Marathon.

If you’ve never seen that course profile, just know it’s not exactly forgiving.

It’s one of the hillier marathons in the Northeast.

My training cycle for that race actually had far less mileage. I averaged 43 miles a week, and peaked at 48 miles.

Instead of pushing volume as high as possible, I focused more on preparing for the terrain — hills, strength, and durability.

The result?

I ran 4:15:59 on a much tougher course.

Only about nine minutes slower than my PR.

That experience reinforced something I’ve seen again and again as both a runner and a coach:

Mileage matters.

But mileage alone isn’t the whole story.

Think of mileage as engine building.

The more consistent aerobic work you do, the larger your endurance engine becomes.

But an engine alone doesn’t determine performance.

How you train — and how you use those miles — matters just as much.

Things like:

• hill strength
• long-run structure
• durability work
• strength training
• recovery

all influence how effectively that aerobic engine translates into performance.

Two runners can run the same weekly mileage and get very different results depending on how those miles are structured.

Most runners fall into one of two traps.

Trap #1: Not enough mileage

They want marathon results but only run two or three times per week.

(Um, that was me for my first 4 marathons. Do not recommend.)

Endurance simply takes time on your feet to build.

Trap #2: Mileage without structure

They increase mileage, but every run looks the same.

No variation.

No progression.

No strength work.

Just more miles.

Mileage helps.

But purposeful mileage helps more.

(Yeah, me again. But I didn’t learn this lesson for about 8 marathons, just ran the mileage - rounding down, most of the time - on my free printed out training plan. In hindsight, what was I thinking?)

After running multiple marathons and experimenting with different training approaches, I’ve landed somewhere in the middle - though closer to the higher volume camp.

I know I need solid mileage to run well in the marathon.

But I’ve also learned that pushing my peak volume into the 70-mile range makes training harder than it needs to be. And honestly, harder than I want it to be. When training starts to become something I dread, everything slips a little — I get sloppy, I procrastinate heading out the door, my focus fades, recovery drags out longer than it should, and the inevitable doubts about race day start creeping in.

These days I’m happiest when my peak weeks land around 60 miles.

It gives me the aerobic development I need without turning every week into a survival test.

{Of course, mileage isn’t the only factor in how a race goes. Injuries, fueling, terrain, weather, and dozens of other variables can influence the outcome. However, I’ll save that for another post.}

The Real Takeaway

Mileage builds your aerobic engine.

But how you train determines how powerful that engine becomes.

For some runners, the key improvement comes from increasing mileage.

For others, it comes from improving the quality and structure of the miles they’re already running.

The trick isn’t just running more. And every runner eventually figures out where their personal balance point is.

For me, it’s around 60 miles per week — enough volume to build the engine without turning training into something I dread.

I'm curious where that point is for you.

What’s the highest mileage week you’ve ever run in training?

And more importantly… did it actually help your race?

~Jess

P.S. Marathon training has a funny way of making you tired in ways that feel productive.