The Three Pillars of Half Marathon and Marathon Training
A simple way to level up your half-marathon or marathon training
If you’ve run a few races, stayed consistent, and started wondering what it would take to get better, you’re in the right place.
At some point, most runners hit the same wall. You’re running regularly, maybe logging decent mileage, but progress feels… flat. You look up training advice and suddenly you’re buried under workout types, acronyms, and plans that feel way more complicated than your life allows.
The good news: you don’t need more workouts.
For half-marathon and marathon runners, three types of runs deliver most of the gains. Nail these, surround them with easy days, and you can move forward without turning running into a second job.
Those three are:
Long runs to build endurance
Threshold runs to raise sustainable speed
Intervals to lift your aerobic ceiling
That’s it.
Why these three matter
Each of these workouts trains a different but essential system. Together, they cover the full picture without overlap or fluff.
Long runs build the engine. Time on your feet strengthens the aerobic system, improves fueling efficiency, and prepares your body for the demands of race day. For half and full marathons, nothing replaces them.
Threshold runs teach control. They raise the pace you can hold comfortably hard, so race effort feels smoother and more sustainable instead of falling apart late.
Intervals sharpen the top end. Short, controlled hard efforts improve oxygen use and running economy, making all other paces feel easier.
Endurance. Stamina. Speed. Simple, complete, effective.
How hard should these runs feel?
There are lots of ways to measure intensity, but the key is consistency, not precision.
Most runners do best anchoring effort by feel, with pace as a guide when conditions allow.
Long runs: easy, conversational, relaxed
Threshold: comfortably hard, focused, controlled
Intervals: hard but repeatable, never all-out
If numbers help you, great. If they stress you out, ignore them. Training works either way when the effort is right.
Pillar 1: The Long Run
What it is
A continuous easy run at a relaxed, conversational effort.
Why it works
Long runs build aerobic capacity, durability, and confidence. They teach your body to keep going when fatigue sets in, which is the defining skill of distance racing.
How to use it
Keep the effort truly easy
Let duration build gradually over weeks
Avoid turning it into a race or a weekly test
For runners stepping up their training, the long run is about showing up consistently, not pushing limits every weekend.
Optional progression finish
Once you’re comfortable, you can occasionally finish the last 10–20 percent a little stronger. Not hard. Just steady. This builds late-race control without adding another workout.
Pillar 2: Threshold
What it is
Sustained running at a comfortably hard effort you could hold for a while, but not forever.
Why it works
Threshold training improves your ability to clear fatigue and maintain pace. It’s what turns “I can run this pace” into “I can hold this pace.”
How to start
You don’t need long, intimidating efforts. Early on, broken work is often better.
Examples:
Short tempo blocks with easy running between
A steady effort for 10–15 minutes
Gradually building total time over weeks
The goal is control, not exhaustion.
Pillar 3: Intervals
What they are
Short, harder efforts with full recovery in between.
Why they work
Intervals improve aerobic power and running economy, making your threshold and race pace feel more manageable.
How to use them
Keep reps short and controlled
Recover enough to repeat the effort well
Stop before form breaks down
Think sharp, not savage. You should finish feeling worked, not wrecked.
How this fits into a week
You don’t need to stack everything at once.
For most runners:
One long run
One quality session (threshold or intervals)
Easy running around them
That’s enough to move forward.
As fitness builds, you might occasionally add a second quality day, but the rule is simple: no more than two demanding sessions in a week.
Common traps to avoid
Running workouts too fast
Control beats intensity every time.
Letting long runs take over
Keep them purposeful but recoverable.
Skipping easy days
Easy running is where adaptation happens.
Overcomplicating the plan
Progress comes from repetition, not novelty.
Where Milo fits in
If you run with an Apple Watch, Milo removes the two biggest sources of friction in structured training.
First, you don’t have to design workouts from scratch. Milo already includes the long runs, threshold sessions, and interval workouts that matter for half and marathon training, tailored to your current fitness and adapting as you improve.
Second, you don’t have to guess how fast to run. Milo gives you clear, personalized paces for every session, so each run has intention without overthinking.
The result is simple execution. You show up, follow the run, and focus on the work instead of the setup.
The takeaway
You don’t need a dozen workout types to run a strong half or full marathon.
Focus on:
One long run
One session that builds control or speed
Easy running everywhere else
Stack weeks. Stay patient. Let fitness build.
That’s how runners move from “pretty consistent” to actually improving.
And if you want tools that stay out of the way while you do it, Milo is there when you’re ready.
Run with purpose. Run with Milo.