SAS: Who Dares Wins
A sea swim off the Isle of Anglesey and a run along the dunes and rocky beaches of Newborough Forest provides just some of the challenge for 1000 athletes in this tough event
With 16,000 runners taking part, and streets lined with supporters, the Brighton Marathon Weekend brings world-class competition and a party atmosphere to the vibrant seaside resort
Some of the world's best triathletes assemble for Challenge Dubai, in the first race of the Triple Crown Series, which sees $1 million go to the man and woman who wins all three events
The world's most scenic ultra-triathlon celebrates its tenth anniversary, as Dylan McNeice fends off a competitive men's field and Gina Crawford aims to regain the title she lost last year
This 100km trail race from Rotorua to Kawerau in New Zealand is part of the Ultra-Trail World Tour, an 11 race series of ultra-marathons that attracts the elite of off-road runners
La Palma is the venue for this 83km ultra marathon, with over 1000 international runners taking on a total of 8500 metres of ascent on the island's spectacular volcanic landscape
Athletes assemble in north Wales for one of the calendar's most challenging triathlons, across stunning Snowdonian mountain scenery and the historic slate quarries of Llanberis
World champion Javier Gomez and chef Gordon Ramsay are among the competitors in this inaugural Ironman in Staffordshire - with a 1.2 mile swim, 56 mile bike ride and half-marathon run
Jenni Falconer has coverage of Britain's second biggest triathlon, as thousands of elites, enthusiasts and celebrities enjoy the course set in the grounds of Winston Churchill's birthplace
This unique triathlon begins with a swim in the River Dee, before taking riders out to the Welsh countryside on the bike, and returning for the run in the ancient city centre
Two thousand athletes amass to take on the most prestigious long course triathlon in the UK, and a crucial qualifier for the Ironman World Championships in Kona
Racing past the iconic sights of the city, Tri Liverpool hosts the second round of the British Triathlon Super Series, the country's premier elite competition
Thirteen thousand triathletes, with elites and celebrities from sport and entertainment, gather for the world's largest triathlon, with the landmarks of London providing an iconic backdrop
This brand new event features one of the fastest courses on the circuit and takes place around the iconic Cardiff Bay, with the start and finish outside the stunning Millennium Centre
The stunning Pembrokeshire coast is the setting for this triathlon, which is made up of three events over three days - the Wales Swim, the Wales Sportive and the Wales Marathon
Nottingham is the venue for this popular and competitive iron-distance triathlon, as 1000 athletes strive to earn the title 'Outlaw' in the world's toughest one day endurance race
Para Tri gives the UK's 12 million disabled people an opportunity to come together, compete and have fun on a dedicated playing field at Dorney Lake, Windsor. Danny Crates and Rob Walker call it.
Iron-distance event, starting with a swim in the waters of Weymouth Bay, the 112 mile bike course takes in the Dorset countryside before a four lap marathon run in Weymouth town centre
Snowdonia hosts the 2015 World Mountain Running Championships, where fitness, bravery, speed and agility are all put to the test in this elite international competition
The final event in the Castle Triathlon Series takes place at Hever Castle in Kent, incorporating elite competition and the world's largest children's triathlon
Kevin Harris and Katharine Merry present this popular event from the historic walled city of York, attracting elite runners and celebrities to its flat and fast course
A freezing loch swim; a bike across the gruelling roads of the Scottish Highlands; a run up and down Britain's highest mountain - only true Bravehearts need apply
A raft of riverbank romps ensues as competitors flock to historic Stockton to take on a variety of obstacles in and around the River Tees, before walking the plank off Captain Cook's ship
Part of the Challenge Triathlon series, a 1.9km swim off Playa Toro, 90km bike on the spectacular switchbacks of the Serra de Tramuntana before a run through the historic city of Paguera
This North Wales winter tri is not for the faint hearted - with a bracing swim in Plas y Brenin's lake, a 69km bike across mountain passes, and a run along the craggy slopes of Moel Siabod
Dean Macey is one of the thousands racing the 10km obstacle course designed to test their endurance, and sense of humour, with mud, ice, tunnels and even a pitch-dark London storm drain
Highlights of the 97km race that climbs from the Atlantic coast to the summit of Teide, Spain's highest mountain. Starting at midnight, runners have 23 hours to complete the epic journey.
Seven day mountain bike stage race across New Zealand's Southern Alps, linking together over 500km of spectacular trails and challenging single-track in a stunning part of the world
A thousand international athletes take on 100km of trail from Rotorua to Kawerau in New Zealand. The spectacular course takes them through some breath-taking scenery.
Katherine Merry presents the UK's flattest, fastest and friendliest marathon, first run in 1908, as thousands of runners aim for the finish at the iconic Emirates Old Trafford Cricket Ground
Thousands of elites and enthusiasts take on the iron-distance course through New Zealand's Southern Alps, with storm conditions making the world's most scenic triathlon even tougher
This tough, thrilling 179km race from Rutland to Melton is reminiscent of the Monuments, attracting top pro teams from home and abroad with its blend of wide roads and dicey farm tracks
Cardiff hosts a spectacular festival of cycling as thousands of riders take part in a mass-ride alongside an elite race. Tough climbs and a city centre finish are the order of the day.
La Palma is the venue for this 83km ultramarathon, with over 1000 international runners taking on a total of 8500 metres of ascent on the island's spectacular volcanic landscape
Enthusiasts and celebrities, including Mel C and Alistair Campbell, take on the iconic course alongside an elite race that includes Alastair Brownlee and European champion India Lee
World Championship qualifying event with 2000 athletes taking on a 1.2 mile swim, 56 mile bike ride and 13.1 mile run in and around the historic Shugborough Estate
Coverage of the 97km race from Tenerife's coast to the summit of Teide - Spain's highest mountain - and back down to the coast: one of trail running's ultimate challenges
The inaugural Swansea Triathlon offers a sprint distance race for elite and age-group athletes, including rugby legend Shane Williams. Aly Vance presents, commentary from Patrick Winterton.
The event that boasts one of the fastest courses on the circuit in and around Cardiff Bay, as the elite race alongside enthusiasts and celebrities such as rugby legend Shane Williams
The streets of the capital provide an iconic backdrop to the action as thousands gather to compete in the world's biggest triathlon. The elite race features World No 2, GB's Jody Stimpson.
Jason Bradbury presents highlights as some of Britain's medal contenders for the Paralympics, including Lauren Steadman and Dave Hill, take on their final race before heading to Rio
Joe Tidy and Annie Emmerson present highlights from Nottingham's iron-distance race as over 1000 athletes of all abilities strive to complete the course and call themselves Outlaw
The opening round of Britain's biggest urban obstacle race takes place at Wembley Stadium. Thousands face mud, tunnels, dizzying climbs, slides and heart-stopping leaps.
A 170km run that takes in 13,500 metres of climbing in just two days, through the Sorteny Valley National Park and the Madriu-Perafita-Claror Valley, an area with world heritage status
Stage race-style tri that takes place over three consecutive days incorporating the Wales Swim, the Wales Sportive and the Wales Marathon all in the Pembrokeshire Coastal National Park
Almost 2000 triathletes from around the world swim and ride through the stunning Basque Country and run through the heart of historic Vitoria, in one of Spain's biggest triathlons
Thousands of triathletes - including some of the world's leading pros, and Welsh rugby legends Shane Williams, Ryan Jones and Ian Gough - swim, ride and run through stunning Pembrokeshire
Trentham Gardens provides the stunning venue for a weekend of triathlon celebrating Stoke on Trent's position as European City of Sport for 2016
Elite runners and celebrities are among the 10,000 competitors racing around York's flat, fast marathon course
Attracting one of the strongest elite fields of the year, this race is fiercely contested due to its flat, fast course. Katharine Merry presents, with commentary from Patrick Winterton.
Caribbean island Aruba is the latest addition to the Challenge calendar, and should attract a top field of elite athletes to its crystal clear waters, rolling hills and white beaches
Competitors swim through the stunning lake at Plas y Brenin, in the shadow of north Wales's beautiful mountains, before taking to the same mountains for a 60km bike race and off-road run
Popular and challenging triathlon across the Isle of Anglesey in North Wales, with 1000 athletes taking on a sea swim and a run across the dunes and rocky beaches of Newborough Forest
This five day, non-stop adventure race sees teams of four tested to the limits 600km across Ireland, including mountain ascents, sea kayaking, massive cycle stages, caving and coasteering
This unique adventure race is a gruelling mix of running and sailing which takes teams of five on a journey up the west coast of Britain, from Wales to Scotland