Drafting in Duathlon — What It Means & How to Use It

During a duathlon, you can gain a real advantage by riding and running behind other athletes legally and respectfully. This is known as drafting, and it’s essentially free speed — so don’t leave it unused. Here’s how to apply it effectively.

Bike Drafting

Most (though not all) amateur duathlon events are non-drafting, meaning you’re not allowed to ride directly behind another competitor. The legal drafting distance is usually 10 or 12 metres, depending on race distance. This is measured from the front of the bike ahead to the front of your bike.

Riding at the legal 12 m distance reduces aerodynamic drag by about 9%, which can equate to a 25-watt saving, depending on conditions. In practical terms, that means you can pedal about 10% less hard for the same speed.

While the exact benefit varies, the key message is simple: legal drafting can save minutes on your bike split — or allow you to conserve more energy for the final run.

There’s no need to feel guilty about using it. Just follow the rules and, if anything, err on the side of leaving a slightly bigger gap. Because pace naturally ebbs and flows, you’ll need to stay alert to maintain a legal distance. Be considerate of others and be prepared to ride solo or take the front when required.

Run Drafting

There is also a small but real drafting benefit when running. The faster the pace or the stronger the headwind, the greater the gain.

At a fast pace — around 5:28 min/mile (3:23 min/km) — research shows it can be 2% easier to run directly behind another athlete. The benefit decreases rapidly as pace slows, but increases again in strong headwinds.

This means you can either save energy at your current pace or run slightly faster for the same effort, although the gains are smaller than on the bike.

Still, in a close race where every second counts, these marginal gains can add up.