Why Mileage Matters — And What to Do If It Doesn’t Work for You
As a coach, one of the most common questions I get from athletes is: “Why does it seem like someone just as fast as me in workouts pulls away in races?” More often than not, the answer lies in one word: mileage.
Mileage isn't just about bragging rights or pushing through fatigue for toughness points. It’s about building something far more foundational: your aerobic engine. And if you're serious about improving as a runner—especially in races lasting longer than a minute or two—your aerobic engine is the heart of the matter.
What Is the Aerobic Engine?
Think of your aerobic system like a fuel-efficient hybrid car engine. It's what powers your running at any sustainable pace. Whether you're racing a 800m, 5K or a marathon, your ability to process oxygen, convert fuel into energy, and clear waste products efficiently all stems from aerobic fitness.
High mileage contributes to this by:
Increasing mitochondrial density (your cells' energy factories)
Improving capillary networks to deliver more oxygen to muscles
Boosting stroke volume (how much blood your heart pumps per beat)
Teaching your body to burn fat more efficiently as fuel
These aren’t just science perks—they translate into real-world results: you can hold pace longer, recover faster between intervals, and handle more training load over time.
Why Two Runners With Equal Speed Aren’t Always Equal
You might line up next to a runner who hits the same splits as you in 400m repeats, but then watch them disappear halfway through a 5K. That’s the aerobic engine at work.
When the race stretches beyond anaerobic effort, the aerobic base becomes the limiting factor. A runner logging 60 miles per week simply has more gas in the tank than someone running 25—even if their peak speed looks similar in training. They’ve spent more time building efficiency, resilience, and fatigue resistance.
When Mileage Doesn’t Work for You
Here’s the thing—not every athlete can handle high mileage. Some break down physically or mentally when volume climbs too high. That doesn’t mean they can’t build an aerobic engine. It just means they need a smarter route.
Alternatives to traditional mileage that still develop aerobic capacity include:
Double sessions: Two shorter aerobic efforts in one day instead of one long run.
Elliptical or aqua jogging: Low-impact ways to mimic running mechanics.
Cycling or rowing: Great cross-training for aerobic endurance without the pounding.
Tempo efforts in cross-training: You can train threshold on a bike just like you can on a trail.
Hiking or uphill walking: Especially useful for trail runners or during injury recovery.
The key is consistency and intensity control—whether you're running, spinning, or hiking. Mileage builds aerobic strength. Aerobic strength builds performance. But the path to building it isn’t one-size-fits-all. If you're a high-mileage athlete, that’s a powerful asset. If you're not, that doesn't mean you're capped—it means you need a customized, sustainable approach that builds volume in creative ways.
The goal is the same for every athlete: a stronger engine. How you build it is where smart coaching makes all the difference.
Live What You Love,
~ Coach Dusty
