If you’ve ever finished a race thinking, “I felt great early…what happened?”…you’re not alone.
In long-course triathlon, the most common reason athletes underperform isn’t a lack of fitness.
It’s pacing. Whether you’re racing a 70.3 (Half Ironman) or a full Ironman, the difference between a strong finish and a late-race collapse usually comes down to one thing:
How you pace the first half of the race.
This guide breaks down exactly how to pace a 70.3 or Ironman without blowing up, so your run reflects your fitness, not your mistakes.
Almost every pacing mistake starts the same way…You feel good. Race morning adrenaline, fresh legs, and race-day energy create a dangerous illusion; effort feels easier than it actually is.
This leads athletes to:
The problem? That early effort has a delayed cost.
Going out too hard leads to:
You might not feel it at mile 5. But you will feel it at mile 10…or mile 20.
In long-course racing, the goal isn’t to feel good early. It’s to still feel strong late.
One of the biggest challenges in pacing a 70.3 or Ironman is deciding what metric to follow.
Should you trust:
The answer: All of them, but with a clear hierarchy.
Effort, how the race feels, should always guide decisions.
Conditions change:
Effort adjusts with those variables. Numbers don’t.
Use these as boundaries, not targets to chase at all costs.
Heart rate helps you:
But heart rate lags behind effort, so don’t rely on it alone.
The best pacing strategy combines all three, but prioritizes effort.
One of the most effective pacing strategies in endurance racing is simple:
Start controlled. Finish strong.
This is known as a negative split.
Instead of fading over time, you:
Why it works:
In practice, this means:
Most athletes do the opposite:
The negative split requires discipline early, but rewards you late.
In a 70.3 triathlon, the bike determines your run.
If you overbike, even slightly, you compromise everything that comes after.
Overbiking leads to:
Which results in:
For most athletes:
If you want a practical way to pace your Ironman or 70.3, follow these guidelines:
Let the race settle.
Consistency is more important than speed.
Pacing and fueling are connected.
If you pace too hard:
Start fueling early, even if you don’t feel like it.
Watch for:
These are early warning signs. Adjust before it’s too late.
Ask yourself:
“Can I hold this effort for the next hour?”
If the answer is no, you’re going too hard.
The race doesn’t begin until:
That’s where pacing shows.
Most athletes understand pacing intellectually.
But execution breaks down because of:
This leads to:
Pacing isn’t just physical. It’s psychological.
You don’t “figure out” pacing on race day. You train it.
Focus on:
Pacing becomes a skill when it’s practiced, not guessed.
The best long-course athletes:
They don’t win the first half. They dominate the second.
If you want your next 70.3 or Ironman to reflect your fitness, focus less on going faster and more on pacing smarter.
Carly and Tyler Guggemos built Organic Coaching in 2014 with a simple philosophy that works. The idea is to take what you have and grow it to get faster, fitter and stronger. And to do it with the time you have – not the time you wish you had.
For athletes who are ready to take their training to the next level while still thriving and succeeding in their professional and family life.
