IRONMAN 70.3 · Jones Beach · 26 Sept 2026
How to train for IRONMAN 70.3 New York
At Jones Beach speed is the promise, and the course keeps it. A buoyant, sheltered bay, a bike on a closed highway, a run along the Atlantic Ocean. Riders hear "lightning-fast" and relax. They should do the opposite, because a course with nothing on it is a time trial, and a time trial is the hardest way to ride 90.4 km.
Look at the file. The bike is 99.2 percent flat by distance, about as flat as a road course gets. There is not one hill on it that sets the effort for you. Every watt of a Trained athlete's 2:58:52 is chosen, and the ones chosen too early are paid for on the Boardwalk.
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.
- Swim1.93 kmDistance only
- Bike90.4 km253 m upCourse file
- Run21.5 km36 m upCourse file
Zach's Bay holds the swim, a protected inland bay at Jones Beach State Park. The organiser describes a 1.2-mile counter-clockwise swim, 1.9 km, and from the exit it is only a brief jog through transition at Jones Beach Theatre to your bike.
The bike runs on the Wantagh Parkway, closed to traffic for the race, with six lanes of highway to ride on and a second round of the parkway before you come back to transition. The file measures 253 m of climbing over the whole leg. The only rise the engine picks out is 328 m at 3 percent, and between the start and that rise lie two uninterrupted flat stretches of 26.8 km and 32.4 km.
The run is the final 21.5 km on the Jones Beach Boardwalk, along the Atlantic Ocean, and the organiser has refreshed the finish line area. The file climbs 36 m in total and the engine reads it as one flat segment.
Course shape by distance
- Flat 99%
- Climbing 0%
- Descending 1%
The longest stretches
- Bike, flat26.8 km29% of the bike
- Bike, flat32.4 km36% of the bike
- Run, flat21.5 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 comes first, and on it aerobic endurance and muscular endurance score 85 and 81. Threshold capacity follows at 70, then aerobic durability and threshold durability level at 66. The bike fills 51 percent of a Trained athlete's day, so those five are the five largest demands on the whole course, and the run's aerobic endurance only arrives in sixth place.
What stands out is how little the course asks for anything sharp. High-intensity capacity reads 42 on the bike and strength and force 40, both far down the list. Ask the engine for a session built from this bike and it returns a single unbroken hour at Zone 4 with a warm-up and a cool-down around it. There is nothing to repeat. There is only one number to hold.
The bands show where that number matters. A Trained athlete swims 38:50, rides 2:58:52 at 182 W and runs 2:02:07, for 5:49:49. The Competitive band, at 5:05:33 from 4.15 W/kg at 75 kg, is about 21 minutes faster on the bike and 18 faster on the run. It rides 249 W on a course where the power figure and the speed hardly part company, so every watt it holds shows up on the clock.
Weather is the variable. The organiser logged a high of 28 C in 2025 and 17 C in 2023, with the water at 19 C in 2024. Environmental resilience scores 10 on every leg, and the range between those two highs is the real reason to check the forecast in race week.
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Fueling resilience55
- Technical skill55
- High-intensity capacity40
- Anaerobic capacity25
- Strength / force20
- Environmental resilience10
- 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
In Nymiva every course and every athlete gets the same twelve scores. The course's come from its file. An athlete's come from their thresholds and their connected training history, and each one is marked with what it was read from and how much confidence it carries. Where the course demands more than the athlete can show, there is a gap. The gaps are ranked by how much of the day they fill, and on a course where the bike is half the day and the swim a ninth, a bike gap outranks a swim gap of the same size by close to five to one.
This page has no reader's numbers, so its season works from an assumption instead: that the gaps fall where the demand is largest. It spreads 24 weeks over 5 developmental blocks and a two-week taper. The first block puts aerobic endurance in the lead for all three sports, the second aerobic durability, the third threshold capacity, the fourth muscular endurance, and the fifth hands the lead back to aerobic endurance before the taper. A member's season is drawn from their own numbers and will not match 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, 51% of the day85 × 51%44
- 02Muscular enduranceBike leg, 51% of the day81 × 51%41
- 03Threshold capacityBike leg, 51% of the day70 × 51%36
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 New York 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 aerobic durability
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityBike aerobic durability
- PriorityRun aerobic 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 aerobic 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 aerobic 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 aerobic 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
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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- 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 | 0:45:50 | 3:14:09 | 2:26:51 | 6:36:50 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:50 | 2:58:52 | 2:02:07 | 5:49:49 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:33:35 | 2:38:13 | 1:43:45 | 5:05:33 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:30:05 | 2:24:30 | 1:31:47 | 4:36:22 |
Pacing plan
- 0 km0.1%30.3 km/h15:38
- 7.9 km-3.5%47.6 km/h0:17
- 8.13 km0%30.8 km/h52:16
- 35 km-3%45.4 km/h0:16
- 35.2 km0.1%30.3 km/h1:04:09
- 67.6 km3%18 km/h1:06
- 67.9 km-0.3%32.3 km/h22:39
- 80.1 km-3.7%48.5 km/h0:12
1 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 44:16.
Where it is decided
Across 59 km of parkway that never changes.
The engine splits the bike into two long flat stretches, 26.8 km and 32.4 km, and together they hold 65 percent of the bike leg. The second of them alone holds 36 percent, the biggest single block of the ride, and it arrives when the legs have stopped feeling fresh and the power has started to drift. A rider holding 182 W through it feels the effort creep upward and lets it. A rider who spent the first stretch above plan feels the same creep and has nothing to answer it with.
That is also why the run is not decided on the run. The Boardwalk is flat, the crowd at the finish is loud, and a Trained athlete spends 2:02:07 out there. Whether those two hours are steady or a slow collapse was settled on the parkway.
Getting it wrong
Six lanes of closed highway invite the first mistake. There is room to ride beside anyone, and matching the rider next to you feels natural. Their plan is not yours. Ninety kilometres of flat road magnify the difference between the two.
The second is the swim. Zach's Bay is sheltered and buoyant, so the water flatters everyone, and a swimmer who pushes an extra minute out of it starts the parkway already short of the patience it demands.
The third is the weather. The high was 17 C in 2023 and 28 C two years later. Runners who plan the Boardwalk for one of those days and get the other either leave time on the course or walk the last miles by the Atlantic Ocean.
Conditions on the day
- 2025high 28 C, low 19 C
- 2024high 23 C, low 18 Cwater 19 C
- 2023high 17 C, low 12 Cwater 18 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 New York 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
- 5:49:49
- Of the day on the bike
- 51%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- Is the IRONMAN 70.3 New York bike course flat?
- As flat as a 90 km course gets. The organiser calls it a flat and fully closed 56-mile course on the Wantagh Parkway, and the file measures 253 m of climbing, 99.2 percent of the ride flat by distance. The only climb the engine picks out is 328 m at 3 percent.
- Where is the swim at IRONMAN 70.3 New York?
- In Zach's Bay, a protected inland bay at Jones Beach State Park. The organiser describes a 1.2-mile counter-clockwise swim, and athletes exit the water to the transition area at Jones Beach Theatre.
- What weather should I expect at Jones Beach?
- The organiser logged a high of 28 C in 2025, 23 C in 2024 and 17 C in 2023, with water at 19 C in 2024 and 18 C in 2023. Prepare for either end of that range.
- 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.
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.