IRONMAN 70.3 · Monterrey · Last raced 1 Mar 2026
How to train for IRONMAN 70.3 Monterrey
Monterrey calls itself the City of Mountains, and the mountains are what you look at here, not what you ride. The organiser sells a fast, flat bike on a freeway, and the file agrees about the flat part: more than 96 percent of the whole course is flat by distance. What people miss is that flat is not level. The bike rises and falls on long, gentle gradients you will barely see, and the riders who lose this race lose it on a slope they never noticed.
The last edition was raced on 2026-03-01, and the organiser has not yet published the next date. The course below is the one the organiser publishes now.
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.
- Swim1.98 km10 m upCourse file
- Bike89.8 km in 2 laps511 m upCourse file
- Run21.4 km110 m upCourse file
It starts in water. The swim is 2 km in the man-made Santa Lucía river, which the organiser describes as warm and with 100 percent visibility, and it runs as a rolling start with the fastest swimmers going first. It ends in the very centre of the city, a few metres from transition in the Macroplaza. The organiser records 26 C for 2023 and 21 C for 2025.
The bike is 2 laps along the express lane of Constitution Freeway, 89.8 km on a paved surface the organiser calls in very good shape. The only features anyone points at are the vehicle bridges, nine short ramps between 150 m and 350 m long, the steepest 165 m at 6.1 percent. They are not the shape of the ride. Each lap drifts gently downhill for its first half and gently back up for its second, and the longest single stretch of the whole leg is 17.4 km of freeway at 0.5 percent, climbing so slowly that the eye reads it as flat.
The run is flat and paved, with a few stairs out of transition, and the engine reads all 21.4 km of it as one flat segment. It finishes at the Mexican History Museum in the Macroplaza.
Course shape by distance
- Flat 96%
- Climbing 2%
- Descending 2%
The longest stretches
- Bike, climbing0.17 km1% of the bike
- Bike, flat17.4 km20% of the bike
- Run, flat21.4 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.
The bike sets the order of everything. The demand model scores aerobic endurance at 85 and muscular endurance at 81 on the bike, threshold capacity at 70 and threshold durability at 67 behind them, and because the bike fills 52 percent of a Trained athlete's day, the five largest demands on the whole course are all bike demands. The run's top pair reads 85 and 81, the same as the swim's.
The bridges leave a mark, but a small one. High-intensity capacity scores 54 on the bike against 40 on the run and the swim, and strength and force 45 against 30 and 20. Hand the bike file to the engine and ask for a session and it returns nine half-minute efforts in Zone 5, each followed by a quarter of an hour of easy riding. That is the whole of the course's intensity, compressed into four and a half minutes of work over two and a half hours.
In the bands, a Trained athlete swims 39:45, rides 3:02:43 at 182 W and runs 2:01:27, for 5:53:55. The Competitive band finishes in 5:09:12 from 4.15 W/kg at 75 kg, about 21 minutes faster on the bike and 18 faster on the run. Its advantage lives on the long gradients, where 249 W held without a lapse turns into minutes.
- Aerobic endurance85
- Muscular endurance81
- Threshold capacity70
- Threshold durability66
- Aerobic durability65
- Technical skill65
- Fueling resilience55
- High-intensity capacity40
- Anaerobic capacity25
- Strength / force20
- Environmental resilience15
- 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 holds the course and the athlete up against the same twelve dimensions. The course is scored from its file. The athlete is scored from their thresholds and connected training history, and each score says what it rests on and how far it can be trusted. Only where the course asks for more than the athlete can show is there a gap, and each gap is weighted by how much of the day it fills. Here that makes the bike worth more than the swim and the run combined, since it fills just over half of a Trained day.
No reader's data sits behind this page, so its season has nothing to measure against. It assumes the gaps fall where the demand is heaviest and lays out 24 weeks in 5 developmental blocks with a two-week taper at the end. Aerobic endurance leads the opening block in every sport. Threshold durability leads the second and threshold capacity the third, then muscular endurance, then aerobic endurance again in the last block before the taper. A member's own season is built from their own numbers and argues with this one wherever those numbers disagree.
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.
- 01Aerobic enduranceBike leg, 52% of the day85 × 52%44
- 02Muscular enduranceBike leg, 52% of the day81 × 52%42
- 03Threshold capacityBike leg, 52% of the day70 × 52%36
The bike takes 52% 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 Monterrey 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 threshold durability
- SupportRun threshold durability
- SupportSwim threshold durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike threshold durability
- PriorityRun threshold durability
- PrioritySwim threshold 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 threshold durability
- SupportRun threshold durability
- SupportSwim threshold 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 threshold durability
- SupportRun threshold durability
- SupportSwim threshold 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 threshold durability
- SupportRun threshold durability
- SupportSwim threshold 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
9× course-matched climbs
0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, then 0.5 min at Zone 5, 15.5 min easy between
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
- 154 min
- Trains anaerobic capacity
- Supports strength force
- Supports muscular endurance
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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- 3
- 4
- 5
- 6
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- 8
- 9
- 10
- 11
- 12
- 13
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- 17
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- 21
- 22
- 23
- 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 | 0:46:55 | 3:18:20 | 2:26:03 | 6:41:18 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:39:45 | 3:02:43 | 2:01:27 | 5:53:55 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:34:23 | 2:41:38 | 1:43:11 | 5:09:12 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:30:48 | 2:27:37 | 1:31:17 | 4:39:42 |
Pacing plan
- 0 km-0.5%33.3 km/h20:55
- 11.6 km-5.2%54.9 km/h0:16
- 11.8 km-0.3%32.3 km/h4:21
- 14.2 km3.1%17.7 km/h0:46
- 14.4 km-0.2%31.8 km/h11:02
- 20.3 km3.4%16.8 km/h1:04
- 20.6 km0%30.8 km/h6:06
- 23.7 km6.1%11 km/h0:54
27 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 44:43.
Where it is decided
On the drag home, twice.
The first half of each lap is kind. The race opens with 11.6 km falling at 0.5 percent, speed comes easily, and the field settles into a pace that feels sustainable because the freeway is quietly helping. Then the lap turns, the gradient reverses, and the same effort buys less speed. That 17.4 km stretch at 0.5 percent holds 20 percent of the bike leg on its own, the largest single block of the ride, and the second lap's drag back repeats the trick.
A rider who holds 182 W on the drag loses a little speed and nothing else. A rider who rides to the speed they had on the way out is working well above plan for the whole of that stretch and cannot tell, because nothing in front of them looks like a hill. They get off the bike at the Macroplaza with the flat run already paid for.
The run itself is flat and short on excuses. A Trained athlete spends 2:01:27 on it, with aid every kilometre, and it tells you exactly how honest the drag was.
Getting it wrong
Chasing the bridges comes first. Nine short ramps, each one inviting a hard effort to the top. The steepest takes 0.6 percent of the bike leg. Standing up on every one of them costs more than it saves and changes nothing about the result.
The second is riding by speed. On a course where half of every lap gently helps and half gently resists, speed is the wrong thing to hold. Ride the effort and let the speed move.
The third is the run's rhythm. Aid every kilometre means twenty chances to break stride on a course with nothing else to interrupt it. The runners who move well here treat the stations as part of the road and keep going.
Conditions on the day
- 2025water 21 C
- 2024water 24 C
- 2023water 26 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 Monterrey 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
- 5:53:55
- Of the day on the bike
- 52%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- Is the IRONMAN 70.3 Monterrey bike course flat?
- Almost. The organiser describes it as almost flat with a few vehicle bridge elevations, two laps on the express lane of Constitution Freeway. The file measures 511 m of climbing over 89.8 km, most of it in long, gentle gradients rather than hills. The steepest ramp is 165 m at 6.1 percent.
- Where is the swim at IRONMAN 70.3 Monterrey?
- In the man-made Santa Lucía river, which the organiser describes as having 100% visibility and warm water. It ends in the centre of the city, a few metres from transition in the Macroplaza, and it runs as a rolling start with the fastest swimmers first.
- What water temperature should I expect?
- The organiser records 21 C in 2025, 24 C in 2024 and 26 C in 2023.
- How many aid stations are on the run?
- The organiser places aid stations every kilometre on a flat, paved run course that is closed to cars and marked every mile and every 5 km.
Course data from the organiser’s published files, analysed 25 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.