He was a good but not outstanding runner in high school, after which he did not compete in the sport for several years until 2013, when he ran the Marine Corps Marathon.
[5] Later in 2017, Kelly won the Road Runners Club of America National Ultra Championship at the Lookout Mountain 50 Miler.
[6] The next year, he set a course record of 23:48:00 at the Wild Oak Trail Run in Virginia[7] and was an age group champion at the ITU Long Distance Triathlon World Championships.
[9] Soon after his Franklins win, Kelly moved with his family to the UK, and in late May 2019, he began an attempt at what he termed the Grand Round.
He then began the cycling section towards Fort William, but safety concerns relating to tiredness led him to abandon the challenge.
With more daylight and the expectation of better weather than in the Spine Race, as well as not having to carry as much equipment, he aimed to beat Mike Hartley’s 1989 record of 65:20.
[12] Although Hartley's best had stood for over thirty years, Kelly's record of 64:46 only lasted eight days until it was beaten by Damian Hall who completed the Way in 61:35.
[16] In July 2021, Kelly set out to run a circuit of the 214 Wainwrights in the Lake District but foot problems and high temperatures caused an end to the undertaking.