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How Ari Klau is Using YouTube to Fuel His Triathlon Ambitions

After the death of his sister in January, the ex-NCAA runner quit his job to become a triathlete. It won't be easy—but Ari Klau is showing viewers every step of his tri transformation.

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The sun was still shining in the Arizona desert when Ari Klau threw off his t-shirt for an evening track workout with Lionel Sanders. Fresh off bike hill repeats the day before, the newly minted triathlete intended to do Sanders’ workout. And a little extra. 

The workout? 5K, 5K, 3K, on three minutes rest, with the pace goal of around 5:05/mile. All while being filmed by his personal cameraman for viewers at home—however it went. 

Before starting his YouTube channel, which has garnered 14,000 subscribers since November, Klau made a decision to not edit his videos to make his workouts look better. Whatever the outcome, he wanted to show his audience the real struggle of a young, aspiring triathlete. 

After a few months of triathlon training, Klau was feeling fit. Despite being new to the sport, he thought he would run through the recovery. After all, he ran over 100-mile weeks in college and is the University of Virginia men’s indoor 3,000m record holder. He assumed he could still run five-minute miles with ease. 

But after the two finished the first 5K in 15:50, Klau stepped onto the grass infield, with a slight grin. “I completely disrespected triathlon training,” he said. “Cannot run 5:04’s like I used to, man. Holy [expletive].” 

Klau and Lionel Sanders at the start of the track workout. Photo: Johnny Pace

Klau is someone who thrives off making decisions and sticking to them. So, to abandon his original plan for this workout (even though it was just one workout), pissed him off. After all, had already sacrificed so much to get just to this point.

Back during his sophomore year of university, Klau experienced severe mental burnout. Between his own racing expectations, school, and a continuous cycle of injuries, his mental health deteriorated.

“I can’t go to practice,” he said to a sports psychologist during his second outdoor track season. “Please help me.” 

After the psychologist agreed to talk with his coach about Klau taking some time away from the sport, he felt like a weight had been lifted from his chest. Klau went home and took three weeks completely off running. Before heading back , though, he needed to decide whether running—or competitive endurance sports at all—was something that genuinely made him happy. 

On his first run back, heading up a one-mile long hill in the ritziest area of his hometown, West Hartford, Connecticut, Klau stopped at the top of the street. As he admired the reddish-purple color in the sky, he made a pledge to stop worrying about running. 

“I was like, “OK, right in this moment, right now, I’m going to make the decision to never think about how stupid and irrational this sport is and I’m just going to make the decision to do it and get better.’” 

And he did. He achieved that school record and made the NCAAs in cross-country. After graduating, he tried to balance his athletic goals while working full-time as a software engineer. But he was constantly dreamed of training. 

Last fall, rehabbing from a foot injury, Klau found a second love for cycling and realized the cross-training helped with his running. He started filming and posting workouts online—since he lived with Spencer Brown, known as “The Athlete Special” on YouTube. It was a creative outlet and a small source of income. It wasn’t until a tragedy, though, that he made another’ don’t-look-back’ life decision.

Klau and his dog, Ani. Photo: Johnny Pace

In January, his sister died unexpectedly and he realized he needed to re-evaluate his career and his goals. Rather than being miserable during the work day, Klau quit his job, started to swim with the hope of making it as a triathlete, and went all-in on YouTube content. 

“There is no amount of money they could have paid me to make me want to do it,” he said. “My day to day was me coding, wishing I was biking.” 

Why not do what you wish you were doing instead?

He routinely averages around 10,000 views now per episode on his YouTube channel, with his most popular video getting about 62,000. Many have resonated with Klau’s work ethic, vulnerability to express himself on camera, and confidence to quit his job in an attempt to make it in a new sport. 

He understands, though, the criticism he’s gotten too for pushing his brand before achieving top results. He knows he hasn’t proven himself as a triathlete yet. Having competed in just one triathlon so far, winning a local race in March with 13 other competitors, Klau understands he still has a long way to go. 

At the end of the day, Klau says, social media has helped fuel his athletic dreams, but (aside from being a bit more brash and abrasive at workouts to heighten the humor) he’s still the same person off-camera. 

“When I talk to the camera I try to just talk to whoever is behind the camera. When there’s a camera around, I don’t think about the fact that on the other side of that camera are a couple thousand people,” he said. 

“I drink espresso all day, I hang out with my dog, and I just love working out.” 

Klau is in the midst of moving to New Hampshire to work with coach James Petersen, and is eager to prove himself in the world of triathlon with more races this summer. Ultimately, he wants to make a career out of the sport, and become one of the best triathletes in the world. He knows that won’t be easy, and he’s willing to be humbled along the way.

Perhaps that is no more evident than that April track session with Sanders. 

As the sun started to set, casting a shadow over half of the track, Klau began to slowly fall off Sanders’ pace. Huffing and puffing with his hands on his hips, Klau stopped and waited for Sanders to finish his 5K rep before grinding out the final 3K of the workout. 

With the session complete, rather than telling his cameraman to stop filming, Klau walked into the infield, shook his head, and muttered, “I’ve got work to do.” 

Days later the video, “Absolutely HUMBLED by Lionel Sanders,” was published on his YouTube channel. It has over 55,000 views.