The son of missionaries, Martin was born in Nagoya, Japan while his parents were stationed there and his family moved to Hawaii when he was 9 months old. He has eight other siblings.[3] He started training in Taekwondo when he was 13 and started competing around the same time. After starting boxing around the age of 15 and accumulated quite a bit of amateur kickboxing fights, he decided to try MMA. Currently, Day is a 4th degree Dan Black Belt in ITF Taekwondo.[4]
Mixed martial arts career
Early career
Starting his career in 2015, Day earned an impressive record of 6–1, before he was invited on Dana White's Contender Series. Day's lone loss in the road prior to DWTNCS came in March 2017 when he suffered defeat to Bellator MMA and LFA veteran Nohelin Hernandez.
Day's first shot under the ZUFFA lights came against Jaime Alvarez on Dana White's Contender Series 6 in August 2017. Day came out early with very solid leg kicks but was unable to get the judges’ decision at the end of the bout.
After the defeat, Day continued to win on the Hawaiian and California regional scenes. Day won all three of his following bouts, two of them by finishes. The final of the three was against the undefeated Brady Huang. Huang was 8-0 going into the matchup with all eight bouts ending by finish and seven of those eight ending in the first round. The two battled URCC 34: Destiny in August 2018 as the co-main event to former UFC veteran Tyson Griffin. Day made quick work of the undefeated star, knocking out Huang in the second round.[4]
On February 18, 2021, it was announced that Day had been released from the UFC.[13]
Post UFC
In his first appearance after leaving the UFC, Day faced Ramon Taveras on April 30, 2022 at Combat Night Pro:Jacksonville. He lost the bout via guillotine choke in the first round.[14]
