IRONMAN 70.3 · Santa Cruz · Last raced 13 Sept 2026
How to train for IRONMAN 70.3 Santa Cruz
Santa Cruz goes by the Surf City Showdown, and the organiser calls the bike a rolling ride along Highway 1. Read the word rolling and you go looking for hills to train on. The file has very few to offer. Across the whole course 87 percent of the distance reads as flat, and the bike has no climb longer than 825 m. What decides the day here is how evenly you ride 90.1 km of coast road that almost never forces your hand.
The last edition was raced on 2026-09-13. The organiser has not yet published the date of the next one, so this page is about the course and how to prepare for it. A Trained athlete covers it in 5:57:28.
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.
- Swim1.94 km5 m upCourse file
- Bike90.1 km668 m upCourse file
- Run21.5 km148 m upCourse file
You start on Santa Cruz Main Beach beside the Santa Cruz Beach Boardwalk, swim clockwise around the Wharf and come out on Cowell's Beach. It is 1.9 km of Pacific Ocean, recorded at 17 C in 2025 and 15 C the year before.
The bike leaves transition at Depot Park, heads north on Highway 1 to a turnaround near Pigeon Point Lighthouse and comes back the same way. That is 90.1 km with 668 m of climbing, and because it is an out-and-back the profile is a mirror. Every dip you drop into going north is a rise you climb coming south. The file holds 16 short rises of 3 percent or steeper. The longest on the way out is 825 m at 5.9 percent near kilometre 25. The steepest on the way home is 568 m at 6 percent near kilometre 58. Between the rises lie long stretches of level road, and the two longest sit either side of the turnaround, 9.3 km each.
The run is an out-and-back too. From Depot Park it crosses the West Cliff Bridge onto the West Cliff Path, rounds Natural Bridges State Park, passes through the surrounding community and follows an access path to a turnaround on the ocean bluffs at Wilder Ranch State Park. Then it comes back, and the last 100 yards are run on the sand of Cowell's Beach. The file measures 148 m of gain over 21.5 km. The engine reads the opening 6.7 km as one flat segment worth 32 percent of the run leg, and the closing 4.9 km as another worth 23 percent.
Course shape by distance
- Flat 87%
- Climbing 6%
- Descending 7%
The longest stretches
- Bike, climbing0.57 km2% of the bike
- Run, flat6.73 km32% of the run
- Run, flat4.91 km23% 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 and muscular endurance above everything else. The demand model scores them 85 and 82 for the bike leg, with threshold capacity at 70 and threshold durability at 68. The bike fills 52 percent of a Trained athlete's day, so the six largest demands on the course all belong to it. The run's own pair reads 85 and 82, the swim's 85 and 81.
Two scores are particular to Santa Cruz. Technical skill reads 65 in the swim, against 35 on the bike, because this swim bends around the Wharf instead of running in a straight line. High-intensity capacity reads 58 on the bike against 45 on the run and 40 in the water, and that is the 16 rises. Ask the engine to turn this bike into a session and it returns twelve hard efforts of 45 seconds in Zone 5, each followed by eight easy minutes. The long gaps are the lesson. This road asks for a short push and then leaves you alone for a long time.
Now the bands. A Trained athlete swims 38:56, rides 3:06:20 at 182 W and runs 2:02:12. Of that ride only about 27 minutes are spent climbing. The rest is flat road and descents. The Competitive band finishes in 5:12:19 from 4.15 W/kg at 75 kg and 4:20 /km threshold pace, 21 minutes quicker on the bike and 18 on the run. None of that comes from the rises. It comes from a higher number held for two and three quarter hours of coast road.
Heat is not the story. The organiser logged highs of 24 C in 2025 and 18 C in 2024, and environmental resilience scores 10 on every leg. If anything the question is cold. The low in 2024 was 11 C, and the day begins in water at 15 C.
- Aerobic endurance85
- Muscular endurance81
- Threshold capacity70
- Aerobic durability65
- Technical skill65
- Threshold durability65
- Fueling resilience55
- 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
A Nymiva plan starts with two readings of the same twelve dimensions. One belongs to the course, taken from its file. The other belongs to you, taken from your thresholds and your connected training history, and each of your scores carries a note on where it came from and how much weight it bears. Where the course asks for more than you can show, you have a gap. Gaps are ranked by the share of race time they touch, which on this course means a bike gap outweighs a swim gap of the same size several times over.
This page holds no one's data. Its season therefore assumes the plainest case, that your gaps sit where the demands are largest, and lays out 24 weeks in 5 developmental blocks before a two-week taper. Aerobic endurance leads the opening block in every sport. Threshold durability leads the second on the bike and the run, with aerobic durability leading in the water. Threshold capacity takes the third block, muscular endurance the fourth, and aerobic endurance returns to lead the last block before the taper. Your own season is built from your own numbers and will disagree with 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, 52% of the day85 × 52%44
- 02Muscular enduranceBike leg, 52% of the day82 × 52%43
- 03Threshold capacityBike leg, 52% of the day70 × 52%37
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 Santa Cruz 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 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
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportBike threshold 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 threshold 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
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, 8 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
- 122 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.
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- 2
- 3
- 4
- 5
- 6
- 7
- 8
- 9
- 10
- 11
- 12
- 13
- 14
- 15
- 16
- 17
- 18
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- 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 | 0:45:57 | 3:23:35 | 2:26:57 | 6:46:29 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:56 | 3:06:20 | 2:02:12 | 5:57:28 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:33:40 | 2:44:50 | 1:43:49 | 5:12:19 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:30:10 | 2:30:32 | 1:31:51 | 4:42:33 |
Pacing plan
- 0 km0.6%27.9 km/h0:23
- 0.18 km3.3%17.1 km/h0:39
- 0.36 km0.1%30.3 km/h17:55
- 9.41 km4.8%13.3 km/h1:13
- 9.68 km0%30.8 km/h7:59
- 13.8 km-3.4%47.2 km/h0:20
- 14 km1.8%22.5 km/h2:36
- 15 km-4.2%50.7 km/h0:47
52 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 45:09.
Where it is decided
Around the turnaround near Pigeon Point Lighthouse.
By kilometre 34 you have climbed eight of the rises. The field has spread out along Highway 1. Then come the two longest flat stretches on the course, 9.3 km going out and 9.3 km coming back, and together they hold about a fifth of the bike leg. Nothing on that road asks you for anything. No rise, no corner, no reason to change gear. It is exactly where a rider who feels good lets 182 W creep upward, because the speed looks so reasonable.
The return is where that gets billed. The steepest climb of the day, 568 m at 6 percent, arrives near kilometre 58, a few minutes after the second flat stretch ends. It takes under 2 percent of the bike leg, so it cannot cost you much time directly. It costs you the run instead, along with the six rises that follow it back to Depot Park.
The run then asks the same question on foot. Its opening 6.7 km are flat and a third of the leg. A runner who heads out at the pace the flat invites meets three short rises of 4 to 5 percent in the middle, and then the sand.
Getting it wrong
The first mistake is preparing for the swim in a pool. This is open ocean that bends around the Wharf, recorded as low as 15 C, and it is the one leg where the course scores technical skill high. Swimmers who have only ever swum straight lines lose more to the turn and the sighting than to their fitness.
The second is training for hills that are not there. Strength and force score 45 on the bike and 38 on the run, far behind aerobic endurance at 85. The longest rise on the course takes a Trained rider a little over four minutes. Long steady hours in the saddle serve Santa Cruz better than steep repeats.
The third comes at the very end. The last 100 yards are on the sand at Cowell's Beach. Legs that were spent on the flat road out to the bluffs at Wilder Ranch State Park have nothing left to give on sand, and everyone watching from the beach can see it.
Conditions on the day
- 2025high 24 C, low 14 Cwater 17 C
- 2024high 18 C, low 11 Cwater 15 C
- 2023high 18 C, low 15 Cwater 17 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 Santa Cruz 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
- 5:57:28
- Of the day on the bike
- 52%
- Dimensions scored per leg
- 12
- Season runway shown
- 24 wk
Questions people ask
- How hilly is the IRONMAN 70.3 Santa Cruz bike course?
- Less than the word rolling suggests. The out-and-back on Highway 1 to a turnaround near Pigeon Point Lighthouse measures 668 m of gain over 90 km, spread across 16 short rises. The longest is 825 m at 5.9 percent and the steepest is 568 m at 6 percent.
- What water temperature should I expect for the Santa Cruz swim?
- The organiser records 17 C in 2025, 15 C in 2024 and 17 C in 2023. The swim starts on Santa Cruz Main Beach, goes clockwise around the Wharf and exits on Cowell's Beach. The course page does not state a wetsuit rule, so check the athlete guide.
- Is the IRONMAN 70.3 Santa Cruz run flat?
- Mostly. The organiser calls it primarily flat, fast and coastal, and the file measures 148 m of gain on the out-and-back to Wilder Ranch State Park. Three short rises of 4 to 5 percent sit in the middle, and the last 100 yards are on the sand.
- 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 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.