Health⏱ 6 min read
How to Calculate Triathlon Pacing Across Swim, Bike, and Run
Triathlon pacing requires managing three different energy systems across three disciplines. Here is how to set target paces for each leg and avoid the mistake that ruins most amateur triathlons.
The cardinal sin of triathlon is going too hard on the bike and walking the run. Proper pacing — especially on the bike — is the single biggest performance lever for athletes at all levels.
Standard Triathlon Distances
FormatSwimBikeRun
Sprint750m20km5km
Olympic1,500m40km10km
Half (70.3)1,900m90km21.1km
Full Ironman3,800m180km42.2km
Swim Pacing
Target swim pace = Comfortable threshold pace + 10-20 sec/100m
If your pool threshold pace is 1:40/100m:
Open-water target: 1:50-2:00/100m
Reasons for the slower target:
- Wetsuit adds buoyancy but changes stroke (offset)
- Navigation (sighting) adds distance
- Mass starts / drafting disruption
- No walls to push off
Swim time estimate: distance / (pace/100) x 100
Olympic tri (1,500m) at 1:55/100m:
= 1500 / 100 x 115 seconds = 1725 seconds = 28:45
Bike Pacing Using FTP
The most important pacing leg — sets up the run.
Sprint triathlon: 85-95% FTP
Olympic: 80-90% FTP
Half Ironman: 75-85% FTP
Ironman: 65-75% FTP
Example: FTP = 220 watts, Olympic tri
Target power: 220 x 0.83 = 183 watts (83% FTP)
Converting power to speed requires knowing aerodynamics
and terrain — but as a rough guide:
183 watts for 75kg rider on flat course ≈ 34-36 km/h average
40km bike at 35 km/h: 40/35 x 60 = 68.6 minutes = 1:08:36
RPE (without power meter): should feel like 7/10 effort —
you can speak in short sentences but not a full conversation.
Run Pacing
Expected run pace after cycling is slower than standalone:
Sprint: add 30-60 seconds per km vs standalone 5km pace
Olympic: add 45-90 seconds per km vs standalone 10km pace
Half Ironman: add 60-120 seconds per km vs standalone half marathon
Ironman: add 90-180 seconds per km vs standalone marathon
If standalone 10km pace is 5:00/km:
Olympic tri target run pace: 5:45-6:30/km
Olympic tri target run time: 10km at 6:00/km = 60 minutes
The "brick" workout trains the body to run off the bike —
20km bike immediately followed by 5km run at race effort.
Legs should feel heavy for the first 1-2km; this normalises
with training.
Total Time Estimation
Total race time = T1 + Swim + T2 + Bike + Run
(T1 = swim-to-bike transition, T2 = bike-to-run)
Typical transition times:
T1: 2-5 minutes (wetsuit removal, helmet on, shoes)
T2: 1-3 minutes (rack bike, swap shoes, race belt)
Olympic triathlon example:
T1: 3 min
Swim 1500m at 1:55/100m: 28:45
T2: 2 min
Bike 40km at 35 km/h: 1:08:34
Run 10km at 6:00/km: 1:00:00
Total: 2:42:19