Pace Plan
2-Hour Half Marathon: Hold 5:41 per km
Sub-two is the half-marathon milestone almost every runner chases. The math is unforgivingly simple: 21.0975 km in under 120 minutes equals a pace of roughly 5:41 per km — for the exact number, drop your numbers in the pace calculator. Hit that pace on every kilometer and you cross in 1:59:58, two seconds to spare.
What 5:41 per km actually feels like
It is a "comfortably hard" effort, roughly 78–82% of your max heart rate. Your first mistake is running the opening kilometers at 5:30 because the crowd is fast. Adrenaline costs nothing in kilometer one; it bills you in kilometer 16. Lock the pace by feel for the first 3 km before checking your watch — most runners drift 5–8 seconds per km faster than their plan when they start hot.
The 5 km splits
Break 21.1 km into four clean 5 km blocks of 28:25 each:
- 0–5 km (28:25): Deliberately tank-throttled. 5:45 feels slow. Good.
- 5–10 km (28:25): Settled, rhythmic. This is where you can relax into the pace.
- 10–15 km (28:22): Sneak 3 seconds per km faster — now you are under target.
- 15–21.1 km (28:20): The payoff block. Finish 20–30 seconds inside 2:00.
Fueling that holds the pace
At 5:41 your legs care less about calories than your brain does about electrolyte balance. Take a gel at kilometers 7 and 14, and a sip of water every aid station after km 5. Skipping fuel to save 10 seconds is the classic sub-two killer — a fade in the last 3 km wipes out far more.
Four habits that keep you under 2:00
- Run the first 3 km by feel, not by ego.
- Think in 5 km blocks, not 21 individual kilometers.
- Fuel on a schedule, before you feel the wall.
- Save your fastest kilometer for the final 10 — closing stronger is what separates 2:01 from 1:59.
Adjust for your goal time
Want 1:55 or 2:05? Run the race distance preset and time in the calculator — it returns your exact per-km pace, and the race predictor will project your half off any recent 5K or 10K you have logged.