IRONMAN 70.3 · Augusta · 25 Jul 2027
How to train for IRONMAN 70.3 Maine
Maine's reputation arrives before you do. The organiser says the point-to-point swim down the Kennebec River was the fastest of any race in the series in 2023, and athletes read that as a promise about the whole day. For a Trained athlete it is a promise about 37:21 of it.
That swim is 10 percent of a Trained athlete's 6:00:00. The bike is 53 percent of it, and that bike has no flat opening to settle into, no flat finish to recover on and no single climb to plan around. It rolls from the second kilometre to the last. Maine is decided by how you ride 899 m of short hills, not by how fast the river carried you.
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.
- Swim1.86 km6 m upCourse file
- Bike90.2 km899 m upCourse file
- Run21.2 km154 m upCourse file
The swim is one pass of 1.9 km downstream on the Kennebec River, start to finish in one direction. You climb out of the water and straight up, because the way into T1 climbs to the top of the valley, and your legs get their first hill before they have touched a pedal.
The bike is one loop of 90.2 km, which the organiser gives as 56 miles, through the Kennebec River Valley and south along the river past rural Maine towns. Read the file and the word "rolling" earns its place. The first rise comes 2 km in. After that the engine counts thirty climbs of 3 percent or steeper and twenty-five descents at the same grade, with no flat stretch longer than about 5 km anywhere. The high point sits near kilometre 79, some 85 m above the start. The steepest ramp, 263 m at 8.7 percent, comes seven kilometres before it, and a 269 m wall at 8.2 percent sits near kilometre 57.
The run is a single loop of 21.2 km through the historic towns of Hallowell and Augusta, with shaded sections beside the river and a finish in front of the State Capitol. It climbs 154 m in total, and the only rises steeper than 3 percent are three short ones. Between kilometre 4 and kilometre 16 the engine reads one unbroken flat segment of more than 12 km.
Course shape by distance
- Flat 79%
- Climbing 11%
- Descending 10%
The longest stretches
- Bike, climbing0.26 km1% of the bike
- Run, flat3.21 km15% of the run
- Run, flat12.3 km58% 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.
On the bike, aerobic endurance at 85 and muscular endurance at 82, then threshold capacity at 70 and threshold durability at 69. Because the bike is more than half the day, the eight biggest demands on the whole course all belong to it. The run's leading pair reads 85 and 82, the swim's 85 and 81.
Two scores are specific to this bike. High-intensity capacity reads 58 against 45 on the run, and strength and force reads 50 against 38, and both come from the same place: a road that tips up every few minutes, for a few minutes at a time. None of the climbs is long. Collectively they are expensive. About an eighth of the bike's distance is climbing at 3 percent or more, and for the Trained band that eighth costs a quarter of the time on the bike.
The bands show where the time sits. A Trained athlete swims 37:21, rides 3:12:11 at 182 W and runs 2:00:28. The Competitive band finishes in 5:13:28 from 4.15 W/kg at 75 kg, riding 2:48:49 and running 1:42:21. Nearly half of the bike gap between those two bands is spent going uphill. On a flat course that share would be close to nothing.
Environmental resilience scores 60 on every leg. The organiser logged a high of 30 C in 2025 and 28 C in 2026, and the river itself was 25 C in 2025. This is a mid-summer race, and it runs like one.
- Aerobic endurance85
- Muscular endurance81
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Environmental resilience60
- Technical skill57
- 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
A demand is half of a gap. Nymiva reads the other half from the athlete: the same twelve dimensions, scored from their thresholds and the training history they connect, with a note on each score saying where it came from and how much weight it bears. Only where the course asks for more than the athlete can show does a gap exist, and the gaps are ranked by the share of the day they sit in. Here that ranking leans hard toward the bike.
This page carries no athlete, so the season on it starts from a plain assumption: the gaps fall where Maine's demands are biggest. On that basis it spans 24 weeks with 5 developmental blocks and a two-week taper. Aerobic endurance leads the first block in all three sports, threshold durability and threshold capacity lead the two after it, muscular endurance leads the fourth, and aerobic endurance returns to lead the block before the taper. A member's own season is built from their numbers, and it will not look like this one.
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, 53% of the day85 × 53%45
- 02Muscular enduranceBike leg, 53% of the day82 × 53%44
- 03Threshold capacityBike leg, 53% of the day70 × 53%37
The bike takes 53% 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 Maine 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
- SupportBike threshold durability
- SupportRun threshold capacity
- SupportRun threshold durability
- SupportSwim threshold capacity
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike threshold 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 threshold 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
- SupportBike threshold durability
- SupportRun threshold capacity
- SupportRun threshold durability
- SupportSwim threshold capacity
- 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
- SupportBike threshold durability
- SupportRun threshold capacity
- SupportRun threshold durability
- SupportSwim threshold capacity
- 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
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
12× rolling-course surges
0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, then 0.8 min at Zone 5, 4.3 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
- 81 min
- Trains threshold durability
- Supports muscular endurance
- Supports high intensity capacity
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.
- 1
- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
- 19
- 20
- 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 | 0:44:04 | 3:33:42 | 2:24:52 | 6:52:38 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:37:21 | 3:12:11 | 2:00:28 | 6:00:00 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:32:18 | 2:48:49 | 1:42:21 | 5:13:28 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:28:56 | 2:34:11 | 1:30:33 | 4:43:40 |
Pacing plan
- 0 km0%30.8 km/h0:16
- 0.14 km-1.5%38.2 km/h0:31
- 0.47 km-0.6%33.8 km/h2:43
- 2 km3.7%15.9 km/h0:43
- 2.19 km-0.1%31.3 km/h1:38
- 3.04 km4%15.1 km/h3:21
- 3.89 km0.6%27.9 km/h2:54
- 5.24 km4.1%14.9 km/h1:05
98 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 46:32.
Where it is decided
In the second half of the bike, on the ramps that come when you are already tired of ramps.
The engine flags the 8.7 percent near kilometre 72 as the steepest sustained climb of the leg. It fills 1.1 percent of the bike leg, which tells you something. No single climb on this course decides anything. What decides it is the sum: thirty rises, each one short enough to attack, each one inviting you to. Ask the engine to turn this bike file into a session and it returns a dozen hard efforts of 45 seconds in Zone 5, each followed by a little over four minutes of easy spinning. Read that as the course's own description of itself. The effort you choose on each of those twelve moments is the race.
Then you get off the bike and find the flat. From kilometre 4 to kilometre 16 the run is one level segment, and that stretch alone holds 58 percent of the run leg. A rider who held 182 W on the ramps runs it steadily beside the river. A rider who went over the top of every climb meets it with nothing left, and 12 km of flat road is a long way to discover that.
Getting it wrong
Trusting the swim. The river does the work and you reach T1 fresher than your watch says you should be. Then comes the climb to the top of the valley, and athletes run it hard because they feel good. That feeling is the current, not fitness.
Riding the first 30 km as if the hills come later. They do not. Four ramps before kilometre 27 run at 5.5 to 6.6 percent, and a rider who takes them on fresh legs pays for them near kilometre 72.
Forgetting the heat on the run. The high in 2025 was 30 C, and a Trained athlete starts running nearly four hours after the gun. The shade along the river helps. It does not cancel a pace set in cooler training weather. The last rise comes inside the final kilometre, short of the State Capitol, and it is 4.5 percent. Leave something for it.
Conditions on the day
- 2026high 28 C, low 13 C
- 2025high 30 C, low 19 Cwater 25 C
- 2024high 25 C, low 18 Cwater 23 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 Maine 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
- 6:00:00
- Of the day on the bike
- 53%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Maine bike course?
- Rolling from the second kilometre to the last. The organiser describes 56 miles of climbs and smooth descents along the Kennebec River, and the course file measures 899 m of climbing. The steepest ramp is 263 m at 8.7 percent, about 72 km in.
- Is the IRONMAN 70.3 Maine swim really that fast?
- It is a point-to-point swim downstream on the Kennebec River, and the organiser calls it the fastest swim of any race in the series worldwide in 2023. The water was 25 C in 2025 and 23 C in 2024. The wetsuit decision is not on the course page, so check the athlete guide in race week.
- What is the IRONMAN 70.3 Maine run course like?
- One loop of 21.2 km through Hallowell and Augusta with 154 m of climbing, shaded in places along the river, finishing in front of the State Capitol. Most of it is flat. Its only real rises are three short ones of 4 to 4.5 percent, the last of them in the final kilometre.
- How hot does it get on race day?
- The organiser logged highs of 30 C in 2025, 28 C in 2026 and 25 C in 2024. A mid-summer race in New England can be warm, and the run starts well into the day for most of the field.
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.