Ranked by elevation

The hardest IRONMAN courses, ranked

34 full-distance IRONMAN courses publish a measured bike climb. Here they are from the most climbing down, with the run, the water and the heat beside each one.

The 10 hardest IRONMAN courses

Ordered by bike elevation gain over 180 km.

1. IRONMAN Leeds

Leeds, United Kingdom · 15 Aug 2027

Climbs 2574 m on the bike and 439 m on the run. Water around 21 °C, highs of 21 °C, 17 h to finish.
2. IRONMAN Lanzarote

Lanzarote, Spain · 15 May 2027

Climbs 2550 m on the bike. Water around 20 °C, highs of 25 °C, 17 h to finish.
3. IRONMAN France

Nice, France · 12 Sept 2027

Climbs 2400 m on the bike. Water around 24 °C, highs of 26 °C, 16 h to finish.
4. IRONMAN Lake Placid

Lake Placid, United States · 25 Jul 2027

Climbs 2164 m on the bike and 383 m on the run. Water around 22 °C, highs of 24 °C, 17 h to finish.
5. IRONMAN Vichy

Vichy, France · 22 Aug 2027

Climbs 2000 m on the bike. Water around 22 °C, highs of 25 °C, 16 h to finish.
6. IRONMAN Switzerland Thun

Thun, Switzerland · 4 Jul 2027

Climbs 1906 m on the bike and 79 m on the run. Water around 17 °C, highs of 27 °C, 17 h to finish.
7. IRONMAN World Championship

Kona, United States · 9 Oct 2027

Climbs 1772 m on the bike and 307 m on the run. Water around 26 °C, highs of 31 °C, 17 h to finish.
8. IRONMAN Kaernten-Klagenfurt, Austria

Klagenfurt, Austria · 13 Jun 2027

Climbs 1754 m on the bike and 84 m on the run. Water around 23 °C, highs of 24 °C, 17 h to finish.
9. IRONMAN Wisconsin

Madison, United States · 12 Sept 2027

Climbs 1702 m on the bike and 231 m on the run. Water around 24 °C, highs of 28 °C, 17 h to finish.
10. IRONMAN Chattanooga

Chattanooga, United States · 26 Sept 2027

Climbs 1580 m on the bike and 351 m on the run. Water around 25 °C, highs of 27 °C, 16 h 30 min to finish.

How the ranking works. Courses are ordered by bike elevation gain, the climbing figure that the most races publish. Equal climbs are split by run elevation, then by race-day heat. Water, air temperature and cut-off sit beside each race, so you can see what the climbing figure leaves out.

10 races in this group publish no elevation figure and are not ranked.

The hardest IRONMAN courses in Europe

1. IRONMAN Leeds

Leeds, United Kingdom · 15 Aug 2027

Climbs 2574 m on the bike and 439 m on the run. Water around 21 °C, highs of 21 °C, 17 h to finish.
2. IRONMAN Lanzarote

Lanzarote, Spain · 15 May 2027

Climbs 2550 m on the bike. Water around 20 °C, highs of 25 °C, 17 h to finish.
3. IRONMAN France

Nice, France · 12 Sept 2027

Climbs 2400 m on the bike. Water around 24 °C, highs of 26 °C, 16 h to finish.
4. IRONMAN Vichy

Vichy, France · 22 Aug 2027

Climbs 2000 m on the bike. Water around 22 °C, highs of 25 °C, 16 h to finish.
5. IRONMAN Switzerland Thun

Thun, Switzerland · 4 Jul 2027

Climbs 1906 m on the bike and 79 m on the run. Water around 17 °C, highs of 27 °C, 17 h to finish.

18 full-distance IRONMAN races are held in Europe. 7 of them carry the hilly label on the bike: IRONMAN Lanzarote, IRONMAN Switzerland Thun, IRONMAN Leeds, IRONMAN Vichy, IRONMAN France, IRONMAN Wales, IRONMAN Portugal-Cascais. Those that climb 2000 m or more are IRONMAN Lanzarote, IRONMAN Leeds, IRONMAN Vichy, IRONMAN France. The IRONMAN in Europe guide compares them on water, cut-off and dates as well.

3 races in this group publish no elevation figure and are not ranked.

The hardest IRONMAN courses in the USA

1. IRONMAN Lake Placid

Lake Placid, United States · 25 Jul 2027

Climbs 2164 m on the bike and 383 m on the run. Water around 22 °C, highs of 24 °C, 17 h to finish.
2. IRONMAN World Championship

Kona, United States · 9 Oct 2027

Climbs 1772 m on the bike and 307 m on the run. Water around 26 °C, highs of 31 °C, 17 h to finish.
3. IRONMAN Wisconsin

Madison, United States · 12 Sept 2027

Climbs 1702 m on the bike and 231 m on the run. Water around 24 °C, highs of 28 °C, 17 h to finish.
4. IRONMAN Chattanooga

Chattanooga, United States · 26 Sept 2027

Climbs 1580 m on the bike and 351 m on the run. Water around 25 °C, highs of 27 °C, 16 h 30 min to finish.
5. IRONMAN Florida

Panama City Beach, United States · 7 Nov 2026

Climbs 545 m on the bike and 77 m on the run. Water around 22 °C, highs of 27 °C, 17 h to finish.

The hardest IRONMAN 70.3 courses

The same ranking over 90 km.

1. IRONMAN 70.3 Nice

Nice, France · 12 Sept 2027

Climbs 1227 m on the bike and 102 m on the run. Water around 24 °C, highs of 26 °C, 8 h 30 min to finish.
2. IRONMAN 70.3 Aix-en-Provence

Aix en Provence, France · 23 May 2027

Climbs 1184 m on the bike and 188 m on the run. Water around 18 °C, highs of 24 °C, 8 h 30 min to finish.
3. IRONMAN 70.3 Vilamoura-Algarve

Vilamoura, Portugal · 3 Apr 2027

Climbs 1169 m on the bike and 8 m on the run. Water around 16 °C, highs of 19 °C.
4. IRONMAN 70.3 Curitiba

Curitiba, Brazil · 21 Mar 2027

Climbs 1119 m on the bike. Water around 25 °C, highs of 29 °C, 8 h 30 min to finish.
5. IRONMAN 70.3 Switzerland

Rapperswil-Jona, Switzerland · 6 Jun 2027

Climbs 1100 m on the bike and 71 m on the run. Water around 17 °C, highs of 24 °C, 7 h 30 min to finish.
6. IRONMAN 70.3 Swansea

Swansea Bay, United Kingdom · 11 Jul 2027

Climbs 1062 m on the bike and 13 m on the run. Water around 16 °C, highs of 24 °C, 8 h 30 min to finish.
7. IRONMAN 70.3 Pennsylvania Happy Valley

State College, United States · 23 May 2027

Climbs 1055 m on the bike and 170 m on the run. Water around 24 °C, highs of 16 °C, 8 h 30 min to finish.
8. IRONMAN 70.3 Coeur d'Alene

Coeur d'Alene, United States · 27 Jun 2027

Climbs 1050 m on the bike and 126 m on the run. Water around 20 °C, highs of 20 °C, 8 h 30 min to finish.
9. IRONMAN 70.3 Weymouth

Weymouth, United Kingdom · 12 Sept 2027

Climbs 1043 m on the bike. Water around 17 °C, highs of 19 °C, 8 h 30 min to finish.
10. IRONMAN 70.3 Mossel Bay

Mossel Bay, South Africa · 22 Nov 2026

Climbs 1020 m on the bike and 365 m on the run. Water around 21 °C, highs of 28 °C, 8 h 30 min to finish.

32 races in this group publish no elevation figure and are not ranked.

A lone runner on a long straight road under a rainbow

What makes an IRONMAN hard

Climbing first: 5 full-distance IRONMAN courses climb 2000 m or more on the bike. Then the run that follows it, the heat, the wind and the water.

The ranking uses the climb because it is measured on most courses. Kona is the reverse case: about 1772 m of climbing, but heat and wind make it one of the hardest days in the sport. For the gentler end, see the easiest IRONMAN courses.

Every full-distance IRONMAN, to filter

Tick hilly, sort by climbing, add a month.

Quick picks

Sort by

Full and ultra 10

IRONMAN Malaysia
Langkawi, Malaysia

Date

21 Nov 2026

Distance

Full

Circuit

IRONMAN

Water

29 °C

Bike

Hilly
Run

Flat

Entries

Open
IRONMAN South Africa, Mossel Bay
Mossel Bay, South Africa

Date

18 Apr 2027

Distance

Full

Circuit

IRONMAN

Water

20 °C

Bike

Hilly
Run

Rolling

Entries

Open
IRONMAN Lanzarote
Lanzarote, Spain

Date

15 May 2027

Distance

Full

Circuit

IRONMAN

Water

20 °C

Bike

Hilly
Run

Rolling

Entries

Open
IRONMAN Switzerland Thun
Thun, Switzerland

Date

4 Jul 2027

Distance

Full

Circuit

IRONMAN

Water

17 °C

Bike

Hilly
Run

Flat

Entries

Sold out
IRONMAN Lake Placid
Lake Placid, United States

Date

25 Jul 2027

Distance

Full

Circuit

IRONMAN

Water

22 °C

Bike

Hilly
Run

Rolling

Entries

Open
IRONMAN Leeds
Leeds, United Kingdom

Date

15 Aug 2027

Distance

Full

Circuit

IRONMAN

Water

21 °C

Bike

Hilly
Run

Hilly

Entries

Open
IRONMAN Vichy
Vichy, France

Date

22 Aug 2027

Distance

Full

Circuit

IRONMAN

Water

22 °C

Bike

Hilly
Run

Flat

Entries

Open
IRONMAN France
Nice, France

Date

12 Sept 2027

Distance

Full

Circuit

IRONMAN

Water

24 °C

Bike

Hilly
Run

Flat

Entries

Sold out
IRONMAN Wales
Pembrokeshire, United Kingdom

Date

19 Sept 2027

Distance

Full

Circuit

IRONMAN

Water

17 °C

Bike

Hilly
Run

Hilly

Entries

Sold out
IRONMAN Portugal-Cascais
Cascais, Portugal

Date

23 Oct 2027

Distance

Full

Circuit

IRONMAN

Water

17 °C

Bike

Hilly
Run

Rolling

Entries

Sold out

Race	Date	Country	Circuit	Distance	Swim	Water	Bike	Run	Entries
IRONMAN Malaysia Langkawi	21 Nov 2026	MY	IRONMAN	Full	Ocean	29 °C	Hilly	Flat	Open
IRONMAN South Africa, Mossel Bay Mossel Bay	18 Apr 2027	ZA	IRONMAN	Full	Sea	20 °C	Hilly	Rolling	Open
IRONMAN Lanzarote Lanzarote	15 May 2027	ES	IRONMAN	Full	Ocean	20 °C	Hilly	Rolling	Open
IRONMAN Switzerland Thun Thun	4 Jul 2027	CH	IRONMAN	Full	Lake	17 °C	Hilly	Flat	Sold out
IRONMAN Lake Placid Lake Placid	25 Jul 2027	US	IRONMAN	Full	Lake	22 °C	Hilly	Rolling	Open
IRONMAN Leeds Leeds	15 Aug 2027	GB	IRONMAN	Full	Lake	21 °C	Hilly	Hilly	Open
IRONMAN Vichy Vichy	22 Aug 2027	FR	IRONMAN	Full	River	22 °C	Hilly	Flat	Open
IRONMAN France Nice	12 Sept 2027	FR	IRONMAN	Full	Sea	24 °C	Hilly	Flat	Sold out
IRONMAN Wales Pembrokeshire	19 Sept 2027	GB	IRONMAN	Full	Bay	17 °C	Hilly	Hilly	Sold out
IRONMAN Portugal-Cascais Cascais	23 Oct 2027	PT	IRONMAN	Full	Bay	17 °C	Hilly	Rolling	Sold out

A triathlete holding her bike above her head, standing in the sea

The hilly label

10 full-distance IRONMAN races carry a hilly label on the bike: IRONMAN Malaysia, IRONMAN South Africa, Mossel Bay, IRONMAN Lanzarote, IRONMAN Switzerland Thun, IRONMAN Lake Placid, IRONMAN Leeds, IRONMAN Vichy, IRONMAN France, IRONMAN Wales, IRONMAN Portugal-Cascais.

On the run, the most climbing measured is about 439 m, at IRONMAN Leeds.

The hardest courses side by side

Climbing, water, heat and cut-off on the same rows.

Race 1

IRONMAN Lanzarote

Race 2

IRONMAN Wales

Race 3

IRONMAN France

Circuit: IRONMANIRONMANIRONMAN
Distance: Full distanceFull distanceFull distance
Terrain: RoadRoadRoad
Swim: 3.8 km3.8 km3.8 km
Bike: 180 km180 km180 km
Run: 42.2 km42.2 km42.2 km
Date: 15 May 202719 Sept 202712 Sept 2027
Country: SpainUnited KingdomFrance
Registration: OpenSold outSold out
Swim venue: OceanBaySea
Average water temperature: 20 °C17 °C24 °C
High air temperature: 25 °C20 °C26 °C
Low air temperature: 18 °C15 °C18 °C
Bike profile: HillyHillyHilly
Bike elevation gain: 2,550 mn/a2,400 m
Run profile: RollingHillyFlat
Overall cut-off: 17 h17 h16 h
Altitude: 44 m21 m11 m
First edition: 199220111982
Swim start: Rolling startRolling startRolling start
Entry fee, from: €778n/an/a

Field	IRONMAN Lanzarote	IRONMAN Wales	IRONMAN France
Circuit	IRONMAN	IRONMAN	IRONMAN
Distance	Full distance	Full distance	Full distance
Terrain	Road	Road	Road
Swim	3.8 km	3.8 km	3.8 km
Bike	180 km	180 km	180 km
Run	42.2 km	42.2 km	42.2 km
Date	15 May 2027	19 Sept 2027	12 Sept 2027
Country	Spain	United Kingdom	France
Registration	Open	Sold out	Sold out
Swim venue	Ocean	Bay	Sea
Average water temperature	20 °C	17 °C	24 °C
High air temperature	25 °C	20 °C	26 °C
Low air temperature	18 °C	15 °C	18 °C
Bike profile	Hilly	Hilly	Hilly
Bike elevation gain	2,550 m	n/a	2,400 m
Run profile	Rolling	Hilly	Flat
Overall cut-off	17 h	17 h	16 h
Altitude	44 m	21 m	11 m
First edition	1992	2011	1982
Swim start	Rolling start	Rolling start	Rolling start
Entry fee, from	€778	n/a	n/a

Runners on a park path during the run leg

Harder than any IRONMAN

The extreme triathlons of the XTRI circuit, such as Norseman or Celtman, finish on a mountain after a cold-water swim. They are outside this ranking because their courses are not comparable with a road IRONMAN; the XTRI circuit page lists them, and the extreme triathlon guide compares their climbing, water and entry rules.

Questions this page is asked

What is the hardest IRONMAN course?

Among the 34 full-distance courses that publish their bike climbing, IRONMAN Leeds climbs the most, about 2574 m over 180 km. The ranking above lists the next nine.

Is Kona the hardest IRONMAN?

Not on climbing: the World Championship course climbs about 1772 m. Its difficulty is the heat, the humidity and the wind across the lava fields, and a field made only of qualifiers.

Which IRONMAN 70.3 is the hardest?

Among the 88 IRONMAN 70.3 courses that publish their bike climbing, IRONMAN 70.3 Nice, with about 1227 m over 90 km.

What is the hardest IRONMAN in Europe?

Among the 15 European full distances that publish their bike climbing, IRONMAN Leeds, with about 2574 m. The European ranking above gives the next four.

Does a harder course have a longer cut-off?

Rarely. Most full-distance IRONMAN races allow 17 h whatever the climbing, so a hilly course leaves less margin.

Find the one you want to suffer on

Month, region and climbing, in the same finder.

Open the race finder Compare a shortlist

The hardest IRONMAN courses, ranked

The 10 hardest IRONMAN courses

1. IRONMAN Leeds

2. IRONMAN Lanzarote

3. IRONMAN France

4. IRONMAN Lake Placid

5. IRONMAN Vichy

6. IRONMAN Switzerland Thun

7. IRONMAN World Championship

8. IRONMAN Kaernten-Klagenfurt, Austria

9. IRONMAN Wisconsin

10. IRONMAN Chattanooga

The hardest IRONMAN courses in Europe

1. IRONMAN Leeds

2. IRONMAN Lanzarote

3. IRONMAN France

4. IRONMAN Vichy

5. IRONMAN Switzerland Thun

The hardest IRONMAN courses in the USA

1. IRONMAN Lake Placid

2. IRONMAN World Championship

3. IRONMAN Wisconsin

4. IRONMAN Chattanooga

5. IRONMAN Florida

The hardest IRONMAN 70.3 courses

1. IRONMAN 70.3 Nice

2. IRONMAN 70.3 Aix-en-Provence

3. IRONMAN 70.3 Vilamoura-Algarve

4. IRONMAN 70.3 Curitiba

5. IRONMAN 70.3 Switzerland

6. IRONMAN 70.3 Swansea

7. IRONMAN 70.3 Pennsylvania Happy Valley

8. IRONMAN 70.3 Coeur d'Alene

9. IRONMAN 70.3 Weymouth

10. IRONMAN 70.3 Mossel Bay