Course comparison
IRONMAN and 70.3 Course Comparison
Eight full-distance and half-distance course profiles scored side by side for swim, bike, and run friction, so you can adjust a neutral split into a realistic race-day estimate.
Why the same athlete finishes different courses at different times
A triathlon distance is fixed but the work required to cover it is not. Two athletes with identical fitness can finish the same 140.6 miles more than an hour apart purely because of what the course asks of them: whether the water is flat or breaking over them, whether the bike leg gives back energy on descents or grinds continuously into wind, and whether the marathon is run in shade or on exposed asphalt in the afternoon.
The profiles below capture those differences as planning modifiers rather than as official race data. Each one records the swim water type, the bike terrain character, the run profile, and the wetsuit likelihood, and combines them into a single 0-10 friction score weighted by how much of the day each discipline occupies - roughly 15% swim, 45% bike, and 40% run for both full and half distances.
Use the score to rank courses against each other, not to predict a finish time. The number tells you which race will punish an aggressive plan hardest; it cannot tell you what shape you will be in on the day.
Course friction, ranked
Combined swim, bike, and run friction for all eight profiles, scored 0–10 and weighted by each discipline’s share of race time. A low score means the course drags on your splits less — not that the race is easy. Use it to rank courses against each other, never to predict a finish time.
One measure, one colour: the bar length is the whole message, and the distance badge beside each name carries the 140.6 / 70.3 distinction. Scores are planning estimates derived from course character, not from timing data. The same figures are tabulated below.
Course friction comparison
All eight profiles ranked from lowest to highest combined friction. Swim, bike, and run columns are 0-10 sub-scores; the overall score weights them by each discipline's share of total race time.
| Course | Distance | Swim | Bike | Run | Overall | Band | Wetsuit likely |
|---|---|---|---|---|---|---|---|
| IRONMAN California | 140.6 | 1.0 | 0.0 | 0.0 | 0.2 | Low friction | Yes |
| IRONMAN Texas | 140.6 | 3.0 | 0.0 | 0.0 | 0.5 | Low friction | No |
| IRONMAN Florida | 140.6 | 4.8 | 2.7 | 0.0 | 1.9 | Low friction | Yes |
| IRONMAN Arizona | 140.6 | 1.0 | 6.0 | 0.0 | 2.9 | Moderate friction | Yes |
| IRONMAN 70.3 Augusta | 70.3 | 1.0 | 6.0 | 0.0 | 2.9 | Moderate friction | Yes |
| IRONMAN 70.3 Oceanside | 70.3 | 1.0 | 6.0 | 4.4 | 4.6 | High friction | Yes |
| IRONMAN Chattanooga | 140.6 | 3.0 | 6.0 | 4.4 | 4.9 | High friction | No |
| IRONMAN 70.3 Chattanooga | 70.3 | 3.0 | 6.0 | 4.4 | 4.9 | High friction | No |
Scores are planning estimates derived from course character, not from timing data or elevation files. Confirm every figure against the current official athlete guide before racing.
Course conditions at a glance
What each course actually asks of you in the water, on the bike, and on the run.
| Course | Location | Swim | Bike | Run |
|---|---|---|---|---|
| IRONMAN Florida | Panama City Beach, Florida | Chop / surf | Flat | Flat |
| IRONMAN Texas | The Woodlands, Texas | Calm open water | Fast | Flat |
| IRONMAN Arizona | Tempe, Arizona | Calm open water | Rolling | Flat |
| IRONMAN California | Sacramento, California | Calm open water | Fast | Flat |
| IRONMAN Chattanooga | Chattanooga, Tennessee | Calm open water | Rolling | Rolling |
| IRONMAN 70.3 Oceanside | Oceanside, California | Calm open water | Rolling | Rolling |
| IRONMAN 70.3 Augusta | Augusta, Georgia | Calm open water | Rolling | Flat |
| IRONMAN 70.3 Chattanooga | Chattanooga, Tennessee | Calm open water | Rolling | Rolling |
IRONMAN Florida
Panama City Beach, Florida
A flat, fast full-distance race profile that suits athletes chasing a steady day and a personal-best style plan.
- Swim — Ocean swim
- Treat the swim with open-water caution even when the race is known as fast; ocean conditions can change the rhythm quickly.
- Bike — Flat / fast bike
- The planning risk is less climbing and more holding steady effort without getting greedy early.
- Run — Flat run
- A flat marathon rewards patience, fueling, and not turning the final 10K into survival mode.
Cutoff pressure
Usually more friendly than hilly full-distance courses, but late wind, heat, and swim conditions can still erase buffer.
Planning angle
Build a conservative bike cap and protect the run; this course is fast only if the first half of the day stays controlled.
IRONMAN Texas
The Woodlands, Texas
A fast full-distance course profile with a lake swim, mostly closed-road riding, and a high-energy run environment.
- Swim — Lake swim
- A controlled lake swim can be easier to pace than ocean water, but traffic and sighting still matter.
- Bike — Flat / fast bike
- Fast roads can tempt athletes above target IF. Use power or effort to keep the marathon intact.
- Run — Spectator-heavy run
- Crowd energy helps, but the run still needs heat-aware pacing and steady fueling.
Cutoff pressure
The speed profile helps cutoff buffer, but a hot day or overbike can turn the run into the limiter.
Planning angle
Use the course speed without chasing it; the best Texas plans keep the bike honest and leave room for heat.
IRONMAN Arizona
Tempe, Arizona
A late-season desert full-distance profile where steady pacing, dry-air fueling, and wind management matter.
- Swim — Lake swim
- Lake water simplifies sighting compared with surf, but cold water and crowding can still affect the start.
- Bike — Rolling / exposed bike
- Desert exposure and wind can matter more than the raw elevation profile.
- Run — Mostly flat run
- A flat run can still punish athletes who under-fuel in dry conditions.
Cutoff pressure
Swim and bike buffer should be checked carefully if wind or cold water affects the early day.
Planning angle
Plan the bike by effort, keep sodium/fluid execution conservative, and do not treat flat as automatically easy.
Use this as a historical/planning profile and verify the current event status before relying on it.
IRONMAN California
Sacramento, California
A fast Sacramento full-distance profile with a downriver swim and flat bike/run style planning assumptions.
- Swim — Downriver swim
- The model treats this conservatively; if the current is favorable, lower your neutral swim pace manually.
- Bike — Flat / fast bike
- Flat speed is useful, but long aero position and wind exposure can still create fatigue.
- Run — Flat urban run
- A flat run is a pacing opportunity only if nutrition and bike restraint were handled early.
Cutoff pressure
This can be a strong buffer course, but official river, weather, and cutoff updates still decide race-day reality.
Planning angle
Use the fast profile to bank calm, not ego; aim for even bike power and a controlled first 10K of the marathon.
IRONMAN Chattanooga
Chattanooga, Tennessee
A full-distance profile known for a fast downriver swim, rolling bike feel, and a community-heavy run.
- Swim — Downriver swim
- Downriver speed can help, but the calculator keeps the assumption conservative unless you adjust swim pace.
- Bike — Rolling bike
- Rolling terrain rewards smooth effort and punishes surging over small climbs.
- Run — Scenic run
- Treat the marathon as effort-based, especially over rises and crowded sections.
Cutoff pressure
The swim can help the day, but rolling terrain means bike pacing still decides how safe the marathon feels.
Planning angle
Let the river help, then ride disciplined; avoid spending the swim gift on a bike surge.
IRONMAN 70.3 Oceanside
Oceanside, California
A coastal 70.3 profile with a sheltered harbor swim, a Camp Pendleton bike route, and a flat-fast run with turns and level changes.
- Swim — Sheltered harbor swim
- Harbor water reduces surf risk, but rolling starts and navigation still matter.
- Bike — Rolling / military-base bike
- The bike can feel fast but should be paced for the run along the coast.
- Run — Flat-fast coastal run
- Flat does not mean perfectly smooth; turns and beach-to-street changes can break rhythm.
Cutoff pressure
Usually manageable with a realistic bike, but early-season pacing errors show up quickly on the run.
Planning angle
Use a composed swim and controlled bike to arrive at the run ready to handle turns, crowds, and coastal exposure.
IRONMAN 70.3 Augusta
Augusta, Georgia
A fast Southern 70.3 profile with a downriver swim, rural bike course, and flat spectator-supported run.
- Swim — Downriver swim
- A quick river swim can improve confidence, but verify current and safety guidance in the athlete guide.
- Bike — Rural bike
- Rural roads require steady pacing and attention to surface, turns, and aid timing.
- Run — Flat shaded run
- Flat shade helps, but heat and humidity can still require a slower first half.
Cutoff pressure
The swim and run profile can help, but humidity and bike pacing still determine the final buffer.
Planning angle
Do not let a quick swim make the bike aggressive; the best Augusta plans respect late-race heat risk.
IRONMAN 70.3 Chattanooga
Chattanooga, Tennessee
A 70.3 profile with a fast downriver swim, rolling Tennessee bike, and riverfront run energy.
- Swim — Fast downriver swim
- The model stays conservative; reduce neutral swim pace manually if you want to model a favorable current.
- Bike — Rolling countryside bike
- Rolling terrain rewards consistent effort and relaxed cadence management.
- Run — Riverfront run
- Expect rhythm changes and pace by effort when the course rolls or crowds tighten.
Cutoff pressure
The swim can create buffer, but the bike/run combination still requires controlled effort.
Planning angle
Accept free speed in the water, avoid surging the bike, and hold a patient first 5K on the run.
How to turn a profile into a split
Start from a neutral split you trust - one built from recent training paces on flat ground in fair conditions - and then apply the course as a correction. Working in that order keeps the two sources of error separate: your fitness estimate and the course estimate. Athletes who build the course assumption into their neutral pace usually end up double-counting it.
- Swim condition adjusts open-water pace, not pool pace.
- Bike terrain sets the ceiling on intensity factor, which protects the run.
- Run profile and heat decide how much buffer the final two hours need.
Reading the friction score
The score measures how much the course slows a given athlete relative to neutral conditions - flat, calm, temperate - not how hard the race is. A flat Ironman scores near zero and is still an Ironman. A 2.4 and a 4.6 tell you the second course demands roughly twice the allowance of the first; neither tells you a finish time. Use it to decide which race suits a personal-best attempt and which deserves a deliberately conservative plan.
What these profiles cannot tell you
They carry no timing data, no elevation files, no wind modelling, and no year-specific route changes. Water temperature decides wetsuit legality on the morning, not the profile. Cutoff clocks move between editions. Treat every number here as a starting assumption that the official athlete guide overrides.
Frequently asked questions
- How much does the course actually change a triathlon finish time?
- Across the profiles on this page the swing between the easiest and hardest course is roughly 6-8% of total moving time for the same athlete. On a 12-hour Ironman that is close to an hour. Bike terrain carries the largest single share because the bike is about 45% of the day, but a hot or rolling run usually does more damage to the last two hours than the terrain does to the bike split.
- Why is a downriver swim still modelled conservatively?
- Current assistance varies with rainfall, dam release schedules, and where the field is positioned in the channel, so it is not something you can bank in advance. The profiles keep the swim assumption neutral and let you lower the swim pace manually once the athlete guide and recent race reports confirm the current is running.
- Does a flat course mean I should ride harder?
- No. Flat courses remove the natural recovery that comes from freewheeling descents, so you hold a steadier, more continuous load and spend longer in aero position. The most common flat-course mistake is treating the lack of hills as permission to raise intensity factor, which shows up as a walked marathon rather than a faster bike split.
- Are these official course data?
- No. Each profile records the planning characteristics of the course - swim water type, bike terrain, run profile, wetsuit likelihood - along with a link to the official race page it was checked against. Route distances, cutoff clocks, aid-station positions, and water-temperature rules change year to year, so always confirm against the current athlete guide before racing.
- Which course is the fastest for a personal best?
- On these profiles the flat full-distance courses - IRONMAN California, Texas, and Florida - score lowest for combined friction, which makes them the usual choices for a time goal. Fast is conditional though: all three carry heat or wind exposure that can erase the terrain advantage, and a fast course only produces a fast time if the bike is ridden with restraint.
Apply a course to your own splits
Each profile above links straight into the course adjustment calculator with its swim, bike, run, and wetsuit settings pre-filled, so you can see the difference between a neutral estimate and a course-adjusted one.
Trust and methodology
How this page should be used
Last updated
August 8, 2026
Maintained by
M Imtinan Farooq
Status
Planning estimate, not a race guarantee
Formula summary
Race-day estimate = neutral splits adjusted by swim, wetsuit, bike, and run modifiers.
Key assumptions
Course labels are broad planning categories, not official segment-by-segment modeling.
Limitations
Official athlete guides, weather, route changes, and safety instructions override this page.