Tenacious Ten Endurance Challenge

Talgarth, United Kingdom • 9 May 2026

Tenacious Ten Hour Endurance Challenge

The Tenacious Ten Hour Endurance Challenge is an endurance running event held at Mynydd Troed in the Black Mountains of Wales. Participants navigate a 3.2 mile loop that is characterized by technical terrain and significant elevation changes. The course begins at the base of the mountain with a steep climb to the summit, followed by sections of open common trails and technical downhill paths.

Running as a loop format, the event allows participants to complete as many laps as possible within a strict 10 hour time limit. After completing the first lap in a clockwise direction, runners may choose to continue in either a clockwise or anti-clockwise direction for subsequent laps. To record a lap, participants must use a laminated card at two specific clip stations: one located at the summit trig point and another at the mountain base. Only laps completed before the final horn sounds are included in the final results.

Registration options include:

  • Solo
  • Pair
  • Team of 4

The event provides a marked route, a medical team, and a refuel zone with food and drinks. Participants must carry mandatory safety equipment, including a waterproof jacket and trousers, a race vest with water capacity, a telephone, a hat, gloves, a first aid kit, and a foil blanket. Trail shoes are required due to the steep and technical nature of the mountain terrain. Visit the organization's website for the most recent information.

Race information

Endurance Loop
Visit the organization's website for the most recent information.
Trail runs nearby

Celebrate a birthday with a Cakeathon in South Wales. Run or walk a flexible number of laps on a 5.3km course through Parc Taf Bargoed. Choose your distance and enjoy a 7-hour event with a finisher's medal and cake.

The BOWUM is a 30-mile ultramarathon exploring the historic Welsh borderlands. The circular route from Monmouth passes three ancient castles and features a mix of trail and road. This inaugural event offers supported checkpoints and encoura..

Tackle the Kymin Dash, a 7 mile road and trail race from Monmouth that climbs to the Round House for panoramic views before descending through fields and bluebell filled woodland. Enjoy a lively finish at Monmouth School Sports Club with Ki..

The MTC Afanc is a 40-mile ultra marathon along National Cycle Route 8 in Wales. It is also the fifth stage of the challenging six-day CYMRUN event. Runners must be prepared for a cup-free race with strict pace requirements and a full manda..