Dive Into Swimrun: Colorado's New Adventure Racing Phenomenon
Imagine this: you're sprinting through Colorado's rugged trails, a wetsuit clinging to your body, swim goggles perched on your forehead. You dive headfirst into the cool waters of Horsetooth Reservoir, swimming a mile before emerging to run again. This cycle repeats, pushing you through one of the most exhilarating races on the planet.
For the first time, Colorado has embraced Swimrun, a thrilling endurance sport that originated in Europe and is now making waves in the American outdoor scene. This unique event merges trail running and open-water swimming, offering a fresh alternative to the traditional triathlon by eliminating the cycling component.
Based on insights from local competitors, race organizers from the Swedish company Ötillö, and world championship winners residing in Colorado, here's everything you need to know about this burgeoning sport and its potential to reshape Colorado's endurance racing landscape.
What is Swimrun? A Sport Born from a 26-Hour Bet
Swimrun is not your average triathlon. While triathlons follow a swim-bike-run format with transition zones, Swimrun alternates between running and swimming throughout the race – no bikes involved.
The sport's origins trace back to 2002 with an epic bet among four Swedish men. They wagered that the last team to reach Sandhamn would cover the costs of hotel, dinner, and drinks. The twist? They had to pass three restaurants on various islands, with each team paying for whatever the team ahead ordered. The race took 26 hours, and these men – Anders Malm, Janne Lindberg, and the Andersson brothers Jesper and Mats – became known as the "Original 4."
What sets Swimrun apart is its tethered-team format. Unlike triathlon relays where individuals complete separate legs, Swimrun partners are literally connected, completing the entire course together. This allows teammates of varying abilities to compete side by side.
"Every course is different, and it's trails instead of pavement. I love that you go back and forth between swimming and running," says David Ritsema, a Greeley-based urologist who participated in Colorado's inaugural event.
Ötillö, meaning "island to island" in Swedish, hosted the first official race in 2006. Today, CNN ranks their world championship among the toughest races globally, featuring 70 kilometers total, including nearly 6 miles of swimming (more than twice an Ironman's swim distance) and a 61K trail ultramarathon.
Training for the Unconventional: Running in Wetsuits and Swimming with Shoes
Training for Swimrun requires athletes to rethink traditional endurance preparation. Unlike triathlons with designated transition areas, Swimrun competitors wear the same gear throughout the race – wetsuits for running and shoes for swimming.
Ritsema, who trains at Seeley Lake north of Greeley, admits to looking "like a doofus" during workouts. He swims a lap in the lake, runs around the neighborhood in his wetsuit, swim cap, and goggles, then jumps back in to repeat the cycle. It's the only way to prepare for the sport's unique demands.
Key equipment considerations include:
- Wetsuits that are comfortable for running and buoyant for swimming
- Shoes with effective drainage for seamless water-to-land transitions
- Swim goggles with UV protection to counteract glare and protect your eyes
- No transition zones mean carrying everything throughout the race
Training challenges extend beyond gear. Unlike triathletes who consume calories during the bike portion, Swimrun athletes must learn to fuel during running segments. The constant discipline switching requires comfort with being either too hot while running or too cold while swimming.
"I tend to balance being kind of cold in the swimming and then not being too warm during the run," shares Justin Daerr, a Boulder resident and seasoned Swimrun competitor.
For optimal performance, consider using electrolyte supplements to maintain hydration during these demanding transitions.
Colorado's Inaugural Event: A Test Case for American Expansion
Colorado's first Swimrun event at Horsetooth Reservoir offered three distance options to cater to various experience levels:
- Colorado Experience (shortest): Under 5 miles running, 1.5 miles swimming
- Middle distance: A moderate challenge for experienced athletes
- Long distance: An ultra-endurance test for elite competitors
As of September 1st, around 150 athletes had registered, with organizers aiming for 200 participants – a promising sign for the sport's growth in Colorado.
Race Director Lars Finanger, overseeing six U.S. Swimrun events, chose Fort Collins for its climate and terrain. Having lived in Boulder for a decade, he saw Horsetooth Reservoir's potential as an ideal venue.
Weather plays a crucial role in Swimrun safety and enjoyment. With water temperatures typically in the low 50s and an October race date, organizers monitor conditions closely. Finanger notes that competitors prefer cold, cloudy conditions over warm sunny days to avoid overheating in wetsuits.
"We want to challenge participants, not endanger them," Finanger emphasizes, noting that extreme cold could prompt course modifications or timing adjustments.
The Community Aspect: Why Teams Make This Sport Special
The tethered partnership format distinguishes Swimrun from individual endurance sports, fostering unique community-building opportunities. Teams of two are literally connected, allowing partners of different skill levels to compete together effectively.
This format encourages multi-generational participation. Gordon Byrn, the 2010 World Championship winner, regularly competes with his 14-year-old son Axel. "A neat aspect is you can race with people of different abilities because of the tether," Byrn explains. "There aren't many events you can do with someone who is less experienced and stay the same speed."
The safety benefits are significant too. The tethered system, combined with buoyant wetsuits, makes drowning nearly impossible. As Finanger notes, "You can literally roll over and be on your back while your teammate pulls you. That's not advised, but I've cramped up before and deployed that tactic myself."
"The opportunity to race with a partner is the best part of it," Daerr emphasizes. "Not just one of the best, but the best part. I love tris, but it's different when you're racing for yourself."
Ötillö even provides a platform on their website where solo athletes can find compatible teammates, fostering community connections before events begin.
Growing Pains and Future Potential in American Markets
Swimrun's growth in America has faced unique challenges. Currently, only six Swimrun events exist in the U.S., compared to the numerous races available in Europe. The COVID-19 pandemic particularly impacted the sport's momentum.
"There was a lot of excitement, and then the sport stalled out during COVID-19," Finanger explains. "I think people became a lot more adventurous on their own during that time. They wanted to do their own thing that didn't require crowds. The last couple of years, we've been clawing our momentum back."
Ötillö's expansion strategy is deliberately measured, unlike the rapid growth model employed by Ironman. Their goal is 10 races each in Europe, North America, and worldwide – a sustainable approach focused on quality over quantity.
The sport's appeal lies in its adventure-focused philosophy rather than pure competition. "You'll usually get about 5% who are out to win it," Byrn observes. "It's really just an adventurous, fun day for most. Everyone is doing something slightly crazy out there. That's the vibe."
Colorado's outdoor recreation economy could benefit significantly from Swimrun's growth. The state's diverse terrain, abundant water bodies, and adventure-seeking population create ideal conditions for the sport's expansion. Success of the inaugural Fort Collins event could position Colorado as a hub for Swimrun development in North America.
The Future of Adventure Racing in Colorado
Swimrun represents a broader shift toward adventure-focused endurance sports that prioritize experience over pure speed. Unlike traditional triathlons conducted primarily on roads and in pools, Swimrun embraces natural terrain and unpredictable conditions.
"I've rarely seen someone do this who wasn't psyched about it afterward," Daerr notes, suggesting strong retention potential for the sport.
The event's emphasis on teamwork, natural settings, and adaptable formats appeals to athletes seeking alternatives to conventional racing. For Colorado's thriving outdoor recreation community, Swimrun offers a fresh challenge that leverages the state's natural advantages.
As athletes like Ritsema discover, the sport perfectly suits those who "enjoy triathlons but don't like biking" while providing a more adventurous alternative to road racing. The trail-based format and ever-changing courses create unique experiences that can't be replicated in traditional racing formats.
Ready to Take the Plunge?
Swimrun's arrival in Colorado signals an exciting evolution in the state's endurance sports landscape. The sport's unique combination of adventure, teamwork, and natural terrain offers athletes a refreshing alternative to traditional racing formats.
For those interested in trying Swimrun, the sport's emphasis on finishing over winning creates a welcoming environment for newcomers. The tethered team format means you don't need to tackle the challenge alone, and the adventure-focused community prioritizes enjoyment over pure competition.
Colorado's diverse terrain and water bodies provide ideal conditions for Swimrun growth. As the sport continues expanding in North America, the success of events like the Fort Collins race could establish Colorado as a premier destination for this emerging discipline.
Whether you're a triathlete seeking a new challenge, a trail runner curious about adding swimming, or an adventure seeker looking for your next epic experience, Swimrun offers a unique opportunity to push your limits while exploring Colorado's stunning natural landscapes.
To prepare for your Swimrun adventure, make sure you have the right gear: quality swim goggles, proper electrolyte supplementation, and if you're tracking your training, consider a GPS fitness watch to monitor your progress across both disciplines.
