Pacing Your Standard Duathlon (10/40/5)

Pacing a 10/40/5 Duathlon — Think of It As One Continuous Effort

A standard duathlon (10 km run → 40 km bike → 5 km run) is typically a 2–3 hour race. Treat it as one continuous race, not three separate parts. 

Your pacing plan should reflect that — manage effort across all legs so you finish strong. Here’s how to do that.

Run 1 (First 10 km)

You shouldn’t treat this like a standalone 10 km race. Instead, pace it more conservatively — approach it like it was the opening of a half-marathon.

Target ranges (based on overall expected race duration):

Combining heart-rate (THR), pace and perceived effort (RPE) is the most reliable — none is perfect on its own, as factors like terrain, weather, or cardiac drift can skew a single metric.

Starting too fast in Run 1 often ruins the rest of the race — pace conservatively to preserve energy for bike + final run.

Bike Leg (40 km)

The bike leg is critical — how you ride will heavily influence your ability to run well off the bike. 

Bike pacing targets:

What to avoid:

• Riding at a power output that’s slightly too high — even small overestimates kill legs for the run. 

• Surging — large shifts between easy and hard effort waste energy.

• Over-pushing on climbs (e.g. using too heavy a gear) — use appropriate gearing to manage effort.

Smart pacing on the bike and good nutrition are your best insurance for finishing strong.

Run 2 (Final 5 km)

This is often the hardest leg — you’ll be riding on fatigue from both run and bike. But done right, you can still finish strong.

Target zones for final run:

After T2, take a moment to settle — don’t sprint from the transition. Once you find your sustainable pace, hold it, and push if you still have energy left near the finish.

Key Principles for a Strong Duathlon Race

• Use recent fitness-based thresholds (FTP, threshold run pace, heart rate) to set your targets — don’t guess.

• Treat the race as a single event, not separate legs — pacing should reflect cumulative fatigue over ~2–3 hours.

• Use a combination of metrics (RPE + HR + pace/power) — no single metric tells the full story under varying conditions.

• Nutrition & energy management matter — fuelling and hydration on the bike are often what decide how well you run the final 5 km.