Middle-distance triathlons: the 13 toughest?

Ironman 70.3, Half Iron, Middle-distance. Whatever you want to call it, 113km racing is on the rise. But which is the world’s toughest 70.3 course? We crunch the stats to pick our 13 hardest middle-distance triathlons from around the world…

What's the toughest Middle-distance triathlon in the world?

13. The Gauntlet, Hever Castle, Kent

The Hever Castle leg of the Castle Triathlon Series is famous for hosting the world’s largest children’s triathlon and more beginner-friendly races than you can poke a track pump at. But what’s often overlooked is how deceptively tough the bike and run routes are of the longer races.


After a unique 1.9km swim that features a Japanese teahouse and two bodies of water (a lake and a river Eden tributary), the Gauntlet’s 90km two-loop bike takes in the high weald of Kent and Ashdown forest. It’s relentlessly rolling and scenic (if you can muster the energy to sightsee), with the high/low point being the 7km-long climb on the High Road south of Hartfield.

The two-loop run, meanwhile, is set on leg-sapping trails and bridle paths to Chiddingstone and back, and is one that’ll keep you on guard throughout and can be very sticky if it’s rained before the race (like it did in 2015). There’s also a nasty little climb at the end of each loop before one of the UK’s best finishing chutes (and post-race food).


The Gauntlet Stats

  • Swim type: lake, 5                               
  • Swim temp: 17°C, 6                              
  • Bike elevation: 1,456m, 6                    
  • Run elevation: 83m, 1                         
  • Run surface type: trail,  7
  • Avg. high temp: 18.9°C, 5                   
  • Psych battle: 4                                  
  • Isolation: 4                                       
  • DNF rate:  3.6%, 3                                  
  • Median time: 6:39:22, 6                       

TOUGH TOTAL 47/100                                            

12. Challenge Half Walchsee-Kaiserwinkl, Walchsee, Austria

Set in the majestic Austrian Tyrol region, Challenge Half Walchsee-Kaiserwinkl gives Challenge Wanaka a push as the race organiser’s most beautiful event. But, like that New Zealand stunner, there’s a sting in the tail provided by the testing bike leg.

After a swim in the crystal-clear Walchsee lake, the two-loop 90km bike takes in the mountainous panorama of the Kaiserwinkl region, subjecting athletes to over 1,000m of elevation gain along the way. The 21km run course is mercifully flat and heads around the lake, along the promenade and through alpine meadows.

Challenge Half Walchsee-Kaiserwinkl Stats

  • Swim type: lake, 5                         
  • Swimp temp: 23°C, 4
  • Bike elevation: 1,596m, 7
  • Run elevation: 132m, 1
  • Run surface type: concrete paths, 5
  • Avg. high temp: 19°C, 6
  • Psych battle: 5
  • Isolation:
  • DNF rate: 4.5%, 4
  • Median time: 5:29:31, 5




11. Israman 113, Eilat, Israel

Israman began life in 1999 and remains the only long-distance triathlon in the Israel’s dedicated multisport scene. Hosting both 113km middle and 226km long-course races, the Israman starts in the southern holiday resort of Eilat, nestled between the mountainous terrain of Jordan to the east and Egypt to the west.

The race then heads north after a swim in the salty Red Sea for the unforgiving Negev desert, starting with a 12km climb straight out of transition up to 600m above sea level. The temperatures in the desert can vary from freezing to 30C, with 60mph crosswinds adding to the gruelling mix.

If the run elevation gain looks small, that number is deceptive (so we’d added a few marks), with the course unique in middle-distance triathlon in that it’s sharply downhill for the first 12km before a coastline finish.

Israman 113 Stats

  • Swim type: calm sea, 4                                                  
  • Swimp temp: 21°C, 4
  • Bike elevation: 1,895m, 8                       
  • Run elevation: 99m, 4                          
  • Run surface type: path, 4
  • Avg. high temp: 19°C, 6
  • Psych battle: 6
  • Isolation: 6
  • DNF rate: 1%, 1                                           
  • Median time: 7:19:12, 7





10. The Snowman Legend, Plas y Brenin, Snowdonia

If snow is unlikely in July, even in the seeming microclimate that is Snowdonia, the Snowman delivers on its promise of being top race organiser Always Aim High’s toughest middle-distance race.

The swim kicks off in the shallow Llyn Mymbyr before an epic 90km bike through the heart of the Snowdonia National Park. The run nearly features as much elevation gain as the bike, taking athletes to the summit of Moel Siabod and straight back down to the finish line at Plas y Brenin.

The Snowman Legend stats

  • Swim type: calm lake, 5                         
  • Swimp temp: 17°C, 6
  • Bike elevation: 1,132m, 4                   
  • Run elevation: 842m, 8           
  • Run surface type: mixed terrain,  6
  • Avg. high temp: 18°C, 5                              
  • Psych battle: 5
  • Isolation: 6
  • DNF rate: 2.63%, 2                          
  • Median time: 6.10.26, 6                 

TOUGH TOTAL  53/100                                           

9. Ironman 70.3 St. George, St. George, Utah, USA

It’s the race where Alistair Brownlee made his statement of 70.3 intent in May 2017 but, despite his course record of 3:41:58, it’s actually one of the toughest Ironman 70.3s on the circuit for us mere mortals.


The one loop swim takes place in the calm, if chilly, waters of the Sand Hollow Reservoir before the bike leg takes in rolling hills and the signature climb up – and through – Snow Canyon State Park. The run, meanwhile, includes scaling Red Hills Parkway and going through the Red Cliffs Desert Reserve, all under the scorching Utah sun.

 Ironman 70.3 St. George stats

  • Swim type: reservoir, 4                                              
  • Swimp temp: 17°C, 6
  • Bike elevation: 1,077m, 5                 
  • Run elevation: 386m, 3    
  • Run surface type: concrete, 5                   
  • Avg. high temp: 23.8C°C, 10                            
  • Psych battle: 7
  • Isolation: 5
  • DNF rate: 3.28%, 3                                                
  • Median time: 6:16:09, 6                 

TOUGH TOTAL  54/100    


8 Immortal  Exmoor

Exmoor, Somerset

It was the first official 113km Ironman race in the world and has established itself as one of the toughest middle-distance events on Planet Earth.  2017 was the final year under the Ironman banner, with Immortal  taking it over in 2018.  This beast of Exmoor has seen over 20,000 athletes tackle the challenging course since 2006

Triathlon greats Chris McCormack, Cat Morrison and Julie Dibens have all topped the Exmoor podium, after battling a 113km course famed for its chilly 1.9km swim in Wimbleball Lake, hilly 90km bike and rolling 21.1km mixed-terrain run route.

Immortal  Exmoor stats

  • Swim type: calm lake, 6
  • Swimp temp: 15°C, 7
  • Bike elevation: 1,391m, 6                 
  • Run elevation: 280m, 2                      
  • Run surface type: mixed terrain, 7
  • Avg. high temp: 18°C, 5
  • Psych battle: 5
  • Isolation: 5
  • DNF rate: 6.58%, 6
  • Median time: 6:29:25, 6

TOUGH TOTAL  55/100                                           

7 Challenge San Gil  Queretaro

Queretaro, Mexico

Although fairly new to Challenge, this 113km toughie in Querétaro (200km north of Mexico City) has been running since 1992. Altitude more than elevation gain plays a major role in the athlete’s toils, with the swim taking place in an artificial lake at an altitude of 2,000m. The bike then climbs even higher on the bike course into the Querétaro Mountains. The run is thankfully flat but the mid-summer Mexican sun keeps the torment coming.

Challenge San Gil  Queretaro stats

  • Swim type: altitude lake, 8
  • Swimp temp: 22°C, 5
  • Bike elevation: 850m, 3
  • Run elevation: 107m, 2                       
  • Run surface type: road, 5                
  • Avg. high temp: 27.4°C, 10
  • Psych battle: 8
  • Isolation: 6
  • DNF rate: 3.58%, 3                             
  • Median time: 6:02:33, 6                     

TOUGH TOTAL 56/100                                             


6. The Lost Sheep

Kenmare, Ireland

During the past 14 years, the Lost Sheep Half Iron Triathlon has established itself as the toughest middle-distance race in Ireland. Organised by Cork Triathlon Club, the race is limited to 400 competitors and is a surefire bet to sell-out each season.

The 1.9km swim takes place in the pretty Kenmare Bay before a consistently lumpy 83km bike, which takes competitors from Kenmare out along the ring of Beara peninsula. Along the way are a duo of monster climbs, switchbacks and a 150m tunnel. While the bike course may be 7km short of official Ironman 70.3 distance, the organisers say they’ve yet to find anyone asking for more.

Like the bike, the 21km run course is rolling throughout and takes place on quiet country roads by the river Sheen before returning to Kenmare town over hilly terrain.

The Lost Sheep stats

  • Swim type: bay, 7                                  
  • Swimp temp: 15°C, 8
  • Bike elevation: 970m, 4                       
  • Run elevation: 250m, 5                     
  • Run surface type: road, 4
  • Avg. high temp: 16°C, 7                      
  • Psych battle: 5
  • Isolation:
  • DNF rate: 6.3%, 6                                  
  • Median time: 5:37:38, 5                    

TOUGH TOTAL 57/100                                            


5 Savageman 70.0

Garrett County, Maryland, USA

The Westernport Wall, the Big Savage Mountain and the Killer Miller. Since 2006, this ultra-tough Maryland cookie, SavageMan, has entered triathlon folklore for its satanic ascents and hair-raising descents.

The brainchild of event founder and course architect, Kyle Yost, the middle-distance race began life in 2006 in Garrett County, located in the heart of the Allegheny Mountains in Western Maryland, USA. The 1.9km swim takes place in the crystal clear waters of Deep Creek Lake before the fun and games begin with 2,000m of elevation gain on the 90km bike route.

After a taste of things to come on the 16% gradient ‘Toothpick’ just 1km out of transition, the route features a long, fast descent to reach the Westernport Wall in Allegany County at 28km. At just four street blocks long, it’s far from the longest climb in triathlon but it’s one of the steepest, with an average gradient of 25% building up to a maximum incline of 31% on the final stretch. A passage deemed so steep it’s long been closed to cars and one that has its one rule book . If the climb isn’t diabolical enough, the road surface is decidedly dicey with potholes galore and the organisers also throw in a posse of pitchfork-wielding devils to line the route. The run then concludes the unique experience on a mix of trails and lakeside roads.

The Savageman stats

  • Swim type:  lake, 6
  • Swimp temp: 19°C, 6
  • Bike elevation: 1,920m, 8                   
  • Run elevation: 377m, 3                     
  • Run surface type:  road & trails,  5
  • Avg. high temp:  22°C, 7
  • Psych battle: 9
  • Isolation: 5
  • DNF rate: 4%, 4                                 
  • Median time:  7:06:08, 7

TOUGH TOTAL  60/100                                           


 4 Altriman Half

Les Angles, Pyrenees, France

We voted the Full Altriman triathlon the second-hardest iron race in the world last year, and the Half Version doesn’t skimp on dishing out the punishment either.

After a 1.9km swim at high altitude, the 92km bike heads north through the Pyrenees and includes a leg-sapping 2,100m of elevation gain and plenty of winding and hairy descents. The run is thankfully flat for the first 8km before a 6km climb takes athletes to 1,700m above sea level.

Altriman Half stats

  • Swim type: lake, 8
  • Swimp temp: 19°C, 6
  • Bike elevation: 2,100m, 8
  • Run elevation: 440m, 4
  • Run surface type: tarmac & trail, 6
  • Avg. high temp: 28°C, 10
  • Psych battle: 9
  • Isolation: 10 
  • DNF rate: 8.92%, 9
  • Median time: 6:56:05, 6

TOUGH TOTAL  76/100                                           


3 AxTri

Aurland, Norway

If a race start on Laguna Beach conjures images of Thailand, the Axtri’s setting couldn’t be further from it. The Aurland fjord is one of the deepest in the world and water temperatures range from 8-20C depending on the depth.

The long 98km bike route boasts 3,100m of elevation gain and travels from Aurland, over Aurlandsfjellet (1,320m above sea level), down to the village of Erdal by the fjord, back the same way over the mountain to Aurland and the eastern end of the lake Vassbygdi-vatnet (T2). The air temperature may drop below the freezing point on top of the mountain on the bike leg, even in August.

Athletes have a 2km respite from the hills at the start of the run before things get hilly for the final 19km, with over a thousand metres of climbing. Support crews are allowed to follow athletes up the valley, but each athlete must carry their own backpack containing all their gear. The run up Aurlandsdalen has seen temperatures close to 30C, so athletes have to prepare for all weather conditions, as well as aching calfs, quads and lungs.

AxTri Stats 

  • Swim type: fjord,10
  • Swimp temp: 8-20°C, 10
  • Bike elevation: 3,100m, 10
  • Run elevation: 1,100m, 10
  • Run surface type: trail, 7
  • Avg. high temp: 14°C,8
  • Psych battle: 10
  • Isolation:  10  
  • DNF rate: 3.44%, 3
  • Median time: 9:02:24, 9

TOUGH TOTAL 87/100                                            


2 The Brutal  Half

Llanberis, Wales

Set in the picturesque and dramatic scenery of Llanberis in Snowdonia, Northern Wales, the Half Brutal is the shortest brother of the increasingly (in)famous Brutal family, which also include the full length (up there as the toughest Iron event on the planet, the double and triple.

The swim section takes place in the chilly Lyn Padarn lake’s water (two laps). What follows is worth the race name: a two-lap bike with 1,524m of total vertical gain in total, one 8km lap of running around the lake to stretch the legs, and then a leg-sapping, lung-busting climb to the top of Mount Snowdon, the highest mountain in Wales, and back down again.

Brutal Half stats

  • Swim type: lake, 7
  • Swimp temp: 15°C, 8
  • Bike elevation: 1,513m, 7
  • Run elevation: 920m, 9
  • Run surface type: mountain paths, 9
  • Avg. high temp: 14°C, 8
  • Psych battle: 10
  • Isolation: 10 
  • DNF rate: 12%, 10
  • Median time: 10:40:53, 10

TOUGH TOTAL 88/100                                           



1 Half X

Ambleside, Cumbria

The Half X is the shorter sibling of the infamous TriathlonX in the Lake District, a race we named as the toughest long-distance triathlon in the world. And like it’s bigger brother, the bike route takes place on the legendary Fred Whitton cyclosportive route and features a run up Scafell Pike and down again.

With 2,800m of elevation gain, the bike route takes in six hill climbs over 20%, with Hardknott Pass topping out at 33%. The half marathon run, meanwhile, is imposing in its own right, taking in the peaks of Nab Scar, Heron Pike and Great Rigg before the final ascent of Fairfield Summit.

Half X stats

  • Swim type: lake swim, 7
  • Swimp temp: 18°C, 7
  • Bike elevation: 2,800m, 10
  • Run elevation: 1,079m, 10
  • Run surface type: Rocky trails, 10
  • Avg. high temp: 17°C, 6
  • Psych battle: 10
  • Isolation: 10
  • DNF rate: 17.3%, 10
  • Median time: 9:01:17,  9