After a successful collegiate career with the Colorado Buffaloes he turned professional in 2020 joining the On Athletics Club coached by Dathan Ritzenhein.

[7] In 2022, Klecker married fellow University of Colorado alum and On Athletics Club teammate Sage Hurta.

[8] Klecker had a successful high school career, leading to two individual state championships his senior year.

[4] Klecker chose to redshirt his Freshman season of Cross Country but competed in indoor and outdoor track, setting PRs of 3:44.55 for 1500m, 7:59.77 for 3000m, and 13:44.23 for 5000m.

Klecker did not repeat his All-American status his Junior year of cross country, placing 67th at the championship race.

In 2018, Klecker repeated as the Mountain Region Champion, and placed 8th in the NCAA XC Championships, his first time in the top 10.

[10] Klecker went on to run a 3000m personal record of 7:47.57, but the indoor championships were cancelled due to the COVID-19 pandemic as well as the entire outdoor season.

He placed fourth to Bowerman Track Club teammates Marc Scott, Grant Fisher, and Sean McGorty.

This performance earned him fourth place (again behind Bowerman teammates Fisher, Scott, and McGorty) in the race and made him the 18th fastest American ever over the distance.

On July 16, 2022, again at Hayward Field in Eugene at the WAC, Klecker ran with the leaders for over 23 laps, a tactical race, finishing 8th in 27:37.73, behind the winner Joshua Cheptegei.

[16] On January 27, 2023 Klecker broke the 13 minute barrier in the 5K, running 12:54.99 at the John Thomas Terrier Classic held at Boston University.

[18] Klecker opened his 2024 season on January 26 running a 5000 m at the Boston University John Thomas Terrier Classic with the goal of hitting the Olympic standard of 13:05.00.

On March 16, Joe competed at the TEN in San Juan Capistrano running 27:09.29 over 10,000 m, missing the Olympic standard of 27:00.00.

Despite not achieving the mark, he stated he was happy with the result saying he had only been running 30 miles in recent weeks due to adductor strain and a stress reaction in his pelvis.