What happens when you take a Peloton treadmill, turn it up to maximum speed, then let an elite athlete run on it for a little more than an hour?  Well, if the athlete is John Raneri you end up with a treadmill world record for the half-marathon of 1:03:08, eclipsing the old mark of 1:03:37 set by Tyler Andrews in 2015.

Remarkably, Raneri ran that time yesterday in his coach's garage in Flagstaff, Ariz., at 7000 feet of altitude (2134 meters).  With a video camera rolling, the shirtless Raneri mounted the treadmill and his coach, James McKirdy, set the machine to 12.5 miles per hour (20.1 kilometers per hour).  Within a few seconds, Raneri was already at full speed, clocking the first mile in 4:55 (about 3:03 through the first kilometer), before he settled in at 4:48 per mile pace (2:59 per kilometer).  He held that pace through 13.101 miles (21.097 kilometers) to reach the full half-marathon distance.

"It was literally set for full speed the entire time," Raneri told Race Results Weekly in a telephone interview yesterday. He added: "I felt 30 seconds faster was possible if the treadmill was able to go faster. I say that in hindsight."

McKirdy had left the garage door open all night to capture the cool mountain air, and Raneri --who has a half-marathon personal best of 1:01:51-- was feeling good through the first half.

"I made it through 10-K in 29:53," Raneri said. "I was like, damn, I'm going to do this thing!"

With the treadmill dictating the pace, Raneri could focus on his form and how he was feeling. He admitted that he had a few rough patches, but was able to push through.

"When I did feel really good I felt like I was dialed in, but I had some rough moments," Raneri said. "Those are like gut checks in a way. For the most part, I was just dialed in."

Raneri had skipped the USA Olympic Trials Marathon in Atlanta last February to focus on the now-cancelled Boston Marathon. Although he hasn't run a race since the Aramco Houston Half-Marathon on January 19 (he's only done personal time trials), he said his mood remains upbeat. He's been able to get in some great training during the COVID-19 lockdown, he said, and he is trying to take the long view. At 28 years-old, he's just entering what are usually the best years for a marathon runner.

"You know, I'm not that frustrated," he said. "I found a lot of confidence doing those time trials. "Just a week ago, I ran 14:06 in a (5-K) time trial. I ran a 29:53 10-K, too, unofficial. I'm just happy to have the opportunity to find a challenge. That really excites me."

Coach McKirdy pointed out that with a 10 to 14-second per mile handicap due to the high altitude, Raneri's time would be worth 60 to 61 minutes at sea level. He was clearly proud of his athlete, who is also a coach within his McKirdy Trained coaching business. In the video of the record attempt, McKirdy can be seen darting around the garage, shouting encouragement to Raneri and reading off his splits. He was clearly just as excited as his athlete.

"We have the fastest garage in Flagstaff," McKirdy joked.

Raneri's performance was part of the special Chaski Challenge of treadmill record attempts which were held this weekend (results pending). Sara Hall and Rene Metivier were taking on the women's treadmill half-marathon world record of 1:20:43, admittedly a much softer mark than Raneri took on. Also, three men --Tyler Andrews, Max King and Mike Wardian-- were trying for the men's marathon (2:20:45) and 50-K (2:56:35 world treadmill records).