IRONMAN 70.3 · Waco · 4 Oct 2026
How to train for IRONMAN 70.3 Waco
Waco sells speed, and the pitch is honest. You swim downstream. The bike is one loop the organiser has made straighter and smoother. The run finishes on the Waco Suspension Bridge. First timers pick it for a gentle debut and fast athletes pick it for a personal best, and both groups make the same mistake. They read the profile and ignore the thermometer.
The organiser logged a high of 34 C in 2024 and 32 C in 2025. Put that beside a course that is 99 percent flat by distance and you have the real shape of the day. Nothing on this course is steep enough to slow you down. The heat will do it instead, and it waits for the run.
By Kian Briel, founder. Analysed by engine 1, updated
What is actually on the road
The organiser's own course files, drawn the way the Event Analyzer draws a member's race.
- Swim1.9 km0 m upCourse file
- Bike89.9 km267 m upCourse file
- Run21.3 km in 2 laps110 m upCourse file
The swim is one downriver pass of the Brazos River, 1.9 km from Pecan Bottom Park to Indian Springs Park, with the current behind you and the Waco Suspension Bridge beside the exit. The water was 27 C in 2024 and 22 C in 2023.
The bike is one loop of 89.9 km through the countryside of rural Waco, past silos and longhorns. The organiser says recent changes made it faster than ever. The run covers 2 laps along the river, from Brazos Park East to Cameron Park and across historic bridges, and it finishes past the bronze cowboys and longhorns that recall the Chisholm Trail, on the oldest suspension bridge in the Southwest.
The file tells a simple story. The first 40.8 km of the bike are one flat segment, and the engine gives it 45 percent of the bike leg. Then comes the only climb worth the name, 550 m at 5.3 percent, which takes 1.7 percent of the leg and lifts you about 40 m above the start. A short drop, 13.4 km of level road, a 359 m descent at 3.9 percent near kilometre 55, and then 34 km of flat road home. 267 m on the bike in all, 110 m on the run. The organiser calls the run rolling. The engine reads the whole leg as one flat segment.
Course shape by distance
- Flat 99%
- Climbing 1%
- Descending 1%
The longest stretches
- Bike, flat40.8 km45% of the bike
- Bike, climbing0.55 km2% of the bike
- Run, flat21.3 km100% of the run
Each row is one unbroken stretch of the course that keeps the same shape the whole way. The number is how much of that leg you spend inside it, and it comes out the same whether you are fast or slow.
What this course asks of each leg
Twelve training dimensions scored for each leg against its own course, the way the Event Analyzer scores a member's race.
It starts with heat. Environmental resilience scores 90 on the swim, the bike and the run, the top score on every leg, and because the bike fills more than half of a Trained athlete's day, the bike's version of it heads the ranking for the whole course. Aerobic endurance follows at 85 on each leg, with muscular endurance at 81 on the bike and the run and threshold capacity at 70 behind.
The low end of the bike list says as much as the top. Technical skill reads 33. High-intensity capacity reads 42 and strength and force 43. A straight, smooth road with one climb gives a rider nothing to handle and nothing to attack. The swim is the leg with a skill question, technical skill at 62 against 33 on the bike, which fits a river with a current running through it.
Now the bands. A Trained athlete swims 38:08, rides 2:58:04 at 182 W and runs 2:00:57 from an input of 5:06 /km threshold pace, for 5:47:09. The Competitive band finishes in 5:03:16 from 4.15 W/kg at 75 kg, about 20 minutes faster on the bike and 18 faster on the run. On this course that difference has nowhere to come from except held power and a run that survives it.
- Environmental resilience90
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Technical skill62
- Fueling resilience55
- High-intensity capacity40
- Anaerobic capacity25
- Strength / force20
- Sprint power5
Nymiva reads what you can already show, from your own data
Connect your training history and the Focus Lab scores the same twelve dimensions this course demands against where you sit today. The gap between the two is what you train.
- MeasuredFrom your thresholds and testsThreshold power, threshold pace, critical swim speed and field tests you have done. The dimensions they can carry are scored directly.
- EstimatedFrom your training historyConnected activities are read for what they prove: long efforts, late-session fade, repeated hard work, fueling on long days. Each score says how it was read.
- ProxyFrom a stand-in, and named as oneWhere only an indirect signal exists, the score carries the proxy it came from and a lower confidence, never a number dressed as a measurement.
- UnmeasuredHonestly blankA dimension nothing in your data can answer stays unmeasured. It is never a zero, and the plan does not pretend to know it.
Every dimension ends in one word
- Develop the course asks more than you can show
- Maintain close enough to hold at the minimum dose
- Covered nothing to build here
- Unmeasured the course needs it, your data cannot say yet
Nymiva reads twelve dimensions on each side of the comparison. The course side comes from the file the organiser publishes. The athlete side comes from thresholds and connected training history, each score marked with where it came from and how far to trust it. A dimension only counts as a gap where the course asks for more than the athlete can show, and each gap is then weighted by the share of race time it governs. The bike is half of a Waco day, so a modest bike gap outranks a large swim gap.
No one's data sits behind this page, so its season assumes the plainest case, that the gaps fall where Waco's demands are largest. It lays out 24 weeks in 5 developmental blocks closed by a two-week taper. Aerobic endurance leads the opening block in all three sports. The second block hands the bike and the swim aerobic durability and gives the run threshold durability. Threshold capacity leads the third block, muscular endurance the fourth, and aerobic endurance returns to lead the fifth. A member's season is built from their own numbers and will set its own order.
Train the bike to protect the run
Which demands matter most across the whole race. A leg's demand counts for as much of the day as that leg takes, so a score of 85 on the bike outweighs the same score on the swim.
- 01Environmental resilienceBike leg, 51% of the day90 × 51%46
- 02Aerobic enduranceBike leg, 51% of the day85 × 51%44
- 03Muscular enduranceBike leg, 51% of the day81 × 51%42
The bike takes 51% of the Trained reference band’s day, so its demands carry the most race weight. What the bike leaves in the legs is what the run gets.
Which demand gets a block, and when
The engine freezes one lead focus per sport on every developmental block, holds the rest at maintenance, and verifies before it reprioritises.
An illustration, not your plan. This page has none of your data, so the season below is the engine’s answer to one stated assumption: that your gaps line up with what IRONMAN 70.3 Waco demands. Your own season is built from your history, your thresholds, the days you can train and the races you have entered, and it will differ from this in its priorities, its sessions and its load.
- 01Run muscular endurance, a practice block4 weeks
- 02Run aerobic endurance, a development block4 weeks
- 03Bike muscular endurance, a practice block4 weeks
- 04Bike aerobic endurance, a development block4 weeks
In the order the allocator places them, general first, most race-like last.
- Week 1PrepPrep
A lead-in week. It develops nothing by design.
- Weeks 2 to 5Foundation 1Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike aerobic durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike aerobic durability
- PriorityRun threshold durability
- PrioritySwim aerobic durability
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- Weeks 10 to 13Foundation 3Closes with a recovery week
- PriorityBike threshold capacity
- PriorityRun threshold capacity
- PrioritySwim threshold capacity
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike aerobic durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 14 to 17Event shaping 1Closes with a recovery week
- PriorityBike muscular endurance
- PriorityRun muscular endurance
- PrioritySwim muscular endurance
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike aerobic durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 18 to 21Event shaping 2Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportBike muscular endurance
- SupportRun muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike aerobic durability
- SupportRun threshold durability
- SupportSwim aerobic durability
- Weeks 22 to 23PeakPeak
The taper. Load comes down toward the race, content stays specific.
- Week 24RaceRace
Race week.
Held at maintenance between blocks
- Runmuscular endurance, aerobic endurance, aerobic durability, threshold capacity, threshold durability
- Bikemuscular endurance, aerobic endurance, aerobic durability, threshold capacity, threshold durability
- Swimaerobic endurance, aerobic durability, threshold capacity, threshold durability, muscular endurance, technical skill
Touches scheduled by each capability’s own decay, at a fraction of its development dose, so earlier work is still there on race day.
The sessions the blocks are built from
One entry per kind of work the block trains, at the intensity that work is meant to be done at. Where the same work runs at several lengths, the entry shows the span it grows across rather than one entry per length.
- Foundation 1 · Weeks 2 to 575 to 240 min
150 to 210 min at Zone 2
BikePower, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 540 to 270 min
180 to 210 min at Zone 3, then 30 min at Zone 4
BikePower, Zone 3Trains aerobic capacity - Foundation 1 · Weeks 2 to 535 to 120 min
90 min at Zone 2
RunPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 550 min
4 x 1.5 min at Zone 3, 6 min easy between
RunHeart rate, Zone 3Trains aerobic capacity - Foundation 1 · Weeks 2 to 545 to 51 min
4 x 8 min at Zone 2, 1 min easy between
SwimPace, Zone 2Trains aerobic capacity - Foundation 1 · Weeks 2 to 547 to 81 min
3 x 1000 m at Zone 3, 0.3 min easy between
SwimPace, Zone 3Trains aerobic capacity
Sustained course race pressure
60 min at Zone 4
Compiled by the deterministic course compiler from the organiser’s file: the course’s one repeatable requirement, rehearsed at a dose the progression allows.
- Bike
- 85 min
- Trains threshold durability
- Supports aerobic durability
24 weeks, laid out backwards from race day
The shortest runway Nymiva builds for this event type, with its blocks, recovery weeks, taper and race week in place.
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- 5
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- 9
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- 11
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- 22
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- 24
- Prep
- Foundation
- Event shaping
- Peak
- Race
- Recovery week
Your own season carries these same phases on your own dates, with the load solved from your fitness and the days you can train, and it changes when your data does.
What each level does on the day
Reference finish times per peer band, the pacing plan the model holds each band to, and where the day is decided.
| Band | Swim | Bike | Run | Finish |
|---|---|---|---|---|
| Recreational2:11 /100m critical swim speed · 2.47 W/kg at 75 kg · 6:08 /km threshold pace | 0:45:00 | 3:13:18 | 2:25:28 | 6:33:46 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:08 | 2:58:04 | 2:00:57 | 5:47:09 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:32:58 | 2:37:32 | 1:42:46 | 5:03:16 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:29:32 | 2:23:52 | 1:30:55 | 4:34:19 |
Pacing plan
- 0 km0%30.8 km/h1:19:24
- 40.8 km5.3%12.3 km/h2:40
- 41.3 km1%26 km/h0:41
- 41.6 km-5.3%55.3 km/h0:11
- 41.8 km-0.1%31.3 km/h25:46
- 55.2 km-3.9%49.4 km/h0:26
- 55.6 km0%30.8 km/h1:06:48
- Run: reach 4:20 /km and this course gives back 43:53.
Where it is decided
On the second loop of the run, and the bill is written on the bike.
A Trained rider holds 182 W for 2:58:04 and starts running more than three and a half hours after the swim start. The run gives nothing back. The engine reads all 21.3 km as one flat segment, with no descent to recover on and no hill to excuse a slow kilometre. The second loop is where a runner finds out what the bike cost.
Ask the engine to turn this bike file into a session and it finds nothing to repeat. No surges, no climbs worth rehearsing. It returns a warm-up, a single hour held in Zone 4, and a cool-down. That is the leg in miniature: one long even effort, and the rider who does best at Waco is the one who treats every kilometre of it the same, including the ones that feel free.
Getting it wrong
The first mistake is the swim clock. The current carries you down the Brazos River, and a swimmer who exits at Indian Springs Park well ahead of plan tends to take that as permission. It is the river talking, not your fitness. Ride the plan you made in training.
The second is the opening 40.8 km. Fresh legs, a smooth straight road and a field still bunched together, with 45 percent of the bike leg sitting in that one flat stretch. The number you ride here sets the temperature of your run, and at Waco that is close to literal.
The third is the run pace itself. Runners arrive with the pace they trained at in cooler weeks and try to hold it across two loops at 34 C. The crowd at Cameron Park and the bridge at the finish pull you forward. Pace the first loop for the heat you are standing in, and save the bridge for the end.
Conditions on the day
- 2025high 32 C, low 17 Cwater 27 C
- 2024high 34 C, low 16 Cwater 27 C
- 2023high 34 C, low 21 Cwater 22 C
From the organiser’s own records. Not a forecast.
Every session is a claim, every block is a test
A plan is not a calendar. Each key session states what it trains and how that is checked, and each block ends with a public verdict before the next one is chosen.
What a block promises
Bike aerobic endurance moves from your baseline to a stated target by the end of Foundation 1
- The baseline is your measured score when the block starts. The target is the score the model predicts for it.
- Verified at the block’s recovery week, by a field test or a refresh of the supply read from your history.
- Confidence rises by agreement between independent signals, never by one metric crossing a line.
- A block that misses its target is a public miss. The next block is chosen from what was proven, not from what was planned.
- 01Stimulus achievedThe work landed in the zone the session named, for the dose it named.
- 02Partially achievedSome of the work landed. The session banks what it can prove.
- 03Not achievedThe load may have been there. The stimulus was not, so nothing is banked.
- 04Data insufficientNo usable stream. The session is neither credited nor blamed.
- Session verified
- Progression banked
- Block verified
- Priority reassessed
- Plan adapted
Your numbers, this course
Analyze IRONMAN 70.3 Waco against my fitness
The same simulation and the same Focus Lab read, on your thresholds instead of a band’s. Three numbers give a finish estimate and a partial read. A connected history gives the whole table.
The first 14 days are free.
- Trained band finish
- 5:47:09
- Of the day on the bike
- 51%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Waco bike course?
- Hardly at all. The one-loop course file climbs 267 m over its 56 miles, and the only real climb is 550 m at 5.3 percent just after kilometre 40. Ninety-nine percent of the whole course reads flat by distance.
- Is the IRONMAN 70.3 Waco swim downriver?
- Yes. It starts at Pecan Bottom Park and runs down the Brazos River to Indian Springs Park, beside the Waco Suspension Bridge. The organiser logged the water at 27 C in 2024 and 2025 and at 22 C in 2023. The wetsuit decision is not on the course page, so check it in race week.
- How hot is it at IRONMAN 70.3 Waco?
- The organiser logged highs of 34 C in 2023 and 2024 and 32 C in 2025, with lows between 16 C and 21 C. Heat is the largest single demand the course makes, on every leg.
- How long is the season on this page?
- The illustrative season runs 24 weeks, with five developmental blocks and a two-week taper. It is built from the course alone. A member's season starts from their own numbers and can be longer.
Course data from the organiser’s published files, analysed 24 Sept 2026 by engine 1, demand model 4. Reference times are simulated for a peer band at a stated reference athlete and are not a prediction for anyone. Nothing on this page is medical advice.
IRONMAN® and IRONMAN 70.3® are registered trademarks, and 5150 is a trademark, of World Triathlon Corporation. Nymiva is an independent training platform and is not affiliated with, sponsored by or endorsed by World Triathlon Corporation. Course data is read from the organiser’s public course pages for the purpose of describing the event.