IRONMAN 70.3 · Alghero · 30 May 2027
How to train for IRONMAN 70.3 Alghero
Alghero is sold as first-timer friendly, and the organiser sums it up in one line: protected swim, scenic ride and flat run. The swim is protected and the ride is scenic. What the line leaves out is in the organiser's own bike file. It is flat for long stretches and then, twice, it points upward at more than 11 percent.
That is the course in one sentence. Flat enough to lull you, steep enough in two places to punish the gearing and the pacing you chose for flat, with a 21.1 km run after it that the organiser also calls flat and the file does not quite agree with.
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 kmDistance only
- Bike90.1 km383 m upCourse file
- Run21.1 km198 m upCourse file
The swim is a single loop of 1.9 km in the bay next to the harbour, in the water of the Coral Riviera below Alghero's medieval walls. It starts and finishes on San Giovanni beach, close to the town centre, with shallow water and a view across to Capo Caccia. The harbour adds shelter, and the organiser says spring conditions are mostly calm. The organiser logged the water at 17 C in 2026 and gives around 18 C as the May average.
The bike has no written description yet. The organiser's overview promises the coastline of Capo Caccia and a ride through vineyards on Sardinian roads. The file supplies the rest: 90.1 km with 383 m of climbing. It holds five climbs. The steepest is 246 m at 11.8 percent near kilometre 17. Then come a 416 m climb at 8.2 percent and a 309 m ramp at 11.3 percent, one after the other, near kilometre 52. Between and around those, two long flat stretches carry the leg. The first, from kilometre 17.6, holds 36 percent of the bike. The second, from kilometre 52.6, holds another 32 percent.
The run is 3 loops. Each one leaves the harbour, goes around the old town streets, follows the seafront wall and heads south along the coastline before turning back. The file measures 198 m of climbing in total, and it arrives in short rises of 4 to 5.6 percent, two to a loop.
Course shape by distance
- Flat 94%
- Climbing 3%
- Descending 3%
The longest stretches
- Bike, climbing0.25 km2% of the bike
- Bike, flat33.7 km36% of the bike
- Bike, flat29.9 km32% of the bike
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.
Start with the bike, because the ranking does. Aerobic endurance scores 85 there and muscular endurance 81, with threshold capacity at 70, and because the bike fills 52 percent of a Trained athlete's day, the top five demands on the whole course are bike demands. Run aerobic endurance comes sixth.
Two bike scores set Alghero apart from the flat race it resembles on paper. Strength and force reads 53, and high-intensity capacity reads 53 too. On a truly flat 90 km both would sit far lower. They are here because of two pitches that last a few minutes each and ask for far more torque than the road around them. Build a session from the file and it returns five one-minute efforts in Zone 5, each followed by more than half an hour of easy riding. Five short questions in a long, level answer.
The run is not an afterthought. It takes 34 percent of a Trained athlete's day, and it scores 85 for aerobic endurance, 82 for muscular endurance and 68 for threshold durability. Technical skill reads 56 on the run against 39 on the bike, which is three laps of turns through old town streets.
In band terms: a Trained athlete swims 38:12, rides 3:00:43 at 182 W and runs 2:00:04, finishing in 5:48:59. The Competitive band reaches 5:04:56 from 4.15 W/kg at 75 kg and 4:20 /km threshold pace. It gains about 21 minutes on the bike and 18 on the run. Almost none of that is found on the two steep pitches. It is found on the 64 km of flat road between them.
Heat is modest for a late-May race. The organiser logged highs of 26 C, 28 C and 29 C across its three editions, with lows between 15 C and 17 C.
- Aerobic endurance85
- Muscular endurance80
- Threshold capacity70
- Aerobic durability65
- Threshold durability65
- Fueling resilience55
- Technical skill55
- 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 does the same sum on both sides of the page. It scores the course on twelve dimensions from the organiser's file and scores the athlete on the same twelve from thresholds and connected training history, each score carrying a note on its source and its confidence. Where the course asks for more than the athlete can show, there is a gap. Each gap is weighted by the share of the day it governs, so on this course a bike gap counts for roughly five times a swim gap of the same size.
There is no reader data here, so the season below assumes the reader's gaps fall where the demands are largest. It runs 24 weeks with 5 developmental blocks and a two-week taper, and for a race on 30 May that puts the first week in December. Aerobic endurance opens the season in all three sports. The second block turns to aerobic durability on the bike and in the water and to threshold durability on the run. Threshold capacity leads the third in every sport, muscular endurance leads the fourth, and aerobic endurance closes the development before the taper. A member's own season starts from their numbers and will look different.
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 Alghero 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
- SupportRun muscular endurance
- SupportBike muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportRun threshold durability
- SupportBike aerobic durability
- SupportSwim aerobic durability
- Weeks 6 to 9Foundation 2Closes with a recovery week
- PriorityRun threshold durability
- PriorityBike aerobic durability
- PrioritySwim aerobic durability
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportRun muscular endurance
- SupportBike 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
- SupportRun muscular endurance
- SupportBike muscular endurance
- SupportSwim muscular endurance
- SupportRun threshold durability
- SupportBike aerobic durability
- SupportSwim aerobic durability
- Weeks 14 to 17Event shaping 1Closes with a recovery week
- PriorityRun muscular endurance
- PriorityBike muscular endurance
- PrioritySwim muscular endurance
- SupportBike aerobic endurance
- SupportRun aerobic endurance
- SupportSwim aerobic endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportRun threshold durability
- SupportBike aerobic durability
- SupportSwim aerobic durability
- Weeks 18 to 21Event shaping 2Closes with a recovery week
- PriorityBike aerobic endurance
- PriorityRun aerobic endurance
- PrioritySwim aerobic endurance
- SupportRun muscular endurance
- SupportBike muscular endurance
- SupportSwim muscular endurance
- SupportBike threshold capacity
- SupportRun threshold capacity
- SupportSwim threshold capacity
- SupportRun threshold durability
- SupportBike 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
5× course-matched climbs
1 min at Zone 5, then 1 min at Zone 5, then 1 min at Zone 5, then 1 min at Zone 5, then 1 min at Zone 5, 35.5 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
- 172 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.
- 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 | 0:45:05 | 3:16:10 | 2:24:24 | 6:35:39 |
| Trained1:51 /100m critical swim speed · 3.03 W/kg at 75 kg · 5:06 /km threshold pace | 0:38:12 | 3:00:43 | 2:00:04 | 5:48:59 |
| Competitive1:36 /100m critical swim speed · 4.15 W/kg at 75 kg · 4:20 /km threshold pace | 0:33:03 | 2:39:52 | 1:42:01 | 5:04:56 |
| Elite1:26 /100m critical swim speed · 5.27 W/kg at 75 kg · 3:50 /km threshold pace | 0:29:36 | 2:26:00 | 1:30:15 | 4:35:51 |
Pacing plan
- 0 km-0.3%32.3 km/h0:44
- 0.39 km0%30.8 km/h1:00
- 0.91 km0.2%29.8 km/h22:00
- 11.8 km-3%45.4 km/h1:11
- 12.7 km4.1%14.9 km/h2:38
- 13.4 km0.2%29.8 km/h5:07
- 15.9 km-5.2%54.9 km/h0:40
- 16.6 km11.8%6.2 km/h2:24
12 more segments in the full plan.
- Run: reach 4:20 /km and this course gives back 44:03.
Where it is decided
Between kilometre 17 and kilometre 82, on 64 km of road with nothing to look at but the power number.
You reach the first flat stretch straight off the steepest climb of the day. The pitch at 11.8 percent costs only 1.5 percent of the bike leg, but it lifts your heart rate and your adrenaline, and after a short descent the road goes level for 33.7 km. That is where the day gets overcooked. The legs feel warm, the road is fast, and holding 182 W feels timid. Hold it anyway.
Near kilometre 52 the course asks its second question: 8.2 percent, a dip, then 11.3 percent. A rider who stayed on plan through the first flat stretch climbs it and settles again. A rider who pressed has to push those two ramps on legs that are already charging interest, and then faces another 29.9 km of flat road. That stretch is where the second half of the bike is lost.
The run settles it. 2:00:04 for a Trained athlete from an input of 5:06 /km threshold pace, three loops, six short rises. Each one is too brief to call a hill. Six of them, on legs that surged at kilometre 52, are enough to turn a steady half marathon into a negotiation along the seafront wall.
Getting it wrong
The first mistake is setting up for the 64 km and forgetting the few hundred metres that are not flat. Riders geared for level road arrive at 246 m of 11.8 percent in the first 17 km and grind it out of the saddle. On the run, the organiser's word flat meets two rises a loop that a flat-course pace plan has no room for.
The second is the calendar. A late-May race means the key months of preparation are winter months, and the 24 weeks on this page start in December. The long bike rides that the flat stretches demand have to be ridden somewhere in January and February.
The third is the first loop of the run. The bike ends on level road, the first 2.7 km out of the harbour are flat, and they invite the pace you wanted all spring. Then comes the first rise, at 4.9 percent. It is back on the second loop and again on the third. By then the fifth and sixth rises of the day arrive on legs for which the seafront wall has stopped being scenery.
Conditions on the day
- 2026high 29 C, low 17 Cwater 17 C
- 2025high 28 C, low 15 C
- 2024high 26 C, low 16 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 Alghero 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
- 5:48:59
- 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 Alghero bike course?
- Mostly flat, with two sharp exceptions. The organiser's file measures 90.1 km with 383 m of climbing, and two long flat stretches hold more than two thirds of the leg. The steepest climb is 246 m at 11.8 percent near kilometre 17, and a 309 m ramp at 11.3 percent follows near kilometre 52.
- What is the water temperature for the swim at Alghero?
- The organiser logged 17 C in 2026 and gives around 18 C as the average for May. The swim is one 1.9 km loop in the bay next to the harbour, starting and finishing on San Giovanni beach. The organiser does not publish the wetsuit decision on its course page.
- Is the IRONMAN 70.3 Alghero run flat?
- The organiser calls it flat. The file measures 21.1 km with 198 m of climbing over three loops, and each loop carries two short rises of 4 to 5.6 percent. Everything between them reads as flat road along the coast.
- How long is the season on this page?
- The illustrative season runs 24 weeks, with five developmental blocks and a two-week taper. For a race on 30 May that means starting in December. A member's season starts from their own numbers and can be longer.
Course data from the organiser’s published files, analysed 23 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 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.