2023-2024: Cross Country – coming off an medical redshirt for the entire 2022-2023 season, the beginning of the season was very strong – including finishing 29^th in the Texas A&M Inv (#2 finisher for ACU) with a 8K PR of 25:08. A respiratory illness the week of the WAC championship forced him to drop out of that race, but he was able to complete the South Central Region meet 2 weeks later, getting 152^nd and the #7 finisher for ACU in his first collegiate 10K XC race.
2022-2023: Cross Country – medical redshirt for the season. Indoors -  redshirted the season, but did run 2 meets unattached, including placing 16^th in the 800 at the TTU Matador Qualifier. Outdoors -  redshirted, but ran in 2 meets unattached, including placing 6^th in the North Texas Classic in Denton in a PR time of 4:00.07

2021-2022: Cross Country – competed in 3 XC meets, including finishing 48th in the Naimadu Classic, but did not compete at the WAC XC Championship. Indoors – placed 4^th at the Pittsburg State 800. Then, at the WAC championships, placed 6th in the 800 and ran the 800 meter leg on the 5th place distance medley relay in his first collegiate conference championship. Outdoors – Finished 5^th in the 800 at the prestigious Michael Johnson Inv at Baylor. After winning the Oliver Jackson Inv 800 in Abilene, he would top off a terrific freshman season by placing 3rd in the WAC championship 800, after running a huge PR in the prelims of 1:51.66.

Before ACU: Competed for Belleville East HS in Illinois, placing 2nd in the St Clair County Boys Championship in the 800, where his PR in the 800 was a 2:00.61. He was first team all-conference in T&F 3 years in HS and also lettered in basketball.

Personal: a 2021 grad of Belleville East HS in Illinois. He is a Sports Management major at ACU. His parents are Michael Shindler and Jeanne Shindler. His Mother, Jeanne Shindler, competing for the Illinois State University swim team. His Grandfather, John Ellis, was a linebacker at the University of Illinois. He also has a twin brother, Brennan. Garrison has also been active with the not-for-profit, Simple Charity, on the ACU campus.