Heilman attends Western Albemarle High School in Crozet, Virginia and trains with the swim club Cavalier Aquatics.

[8][9] Following his addition to the team roster, he was announced as a nominee for the "Boys Rising Star of the Year", a High School Sports Award by USA Today.

[5] The following month, in August at the 2022 Junior National Championships, he won the 100 meter freestyle with a time that made him the first 15-year-old male American swimmer in history to swim the race faster than 50 seconds.

[10] 2022 Junior Pan Pacific Championships The first day of competition at the 2022 Junior Pan Pacific Swimming Championships, contested in Honolulu at the Veterans Memorial Aquatic Center, Heilman won the silver medal in the 200 meter butterfly with a personal best time of 1:56.52, which ranked him as the fourth-fastest American 15 to 16 years of age in history in the event, behind Michael Phelps, Luca Urlando, and Andrew Seliskar.

[17] With a split of 1:47.98 for the second leg of the 4×200 meter freestyle relay later in the same finals session, he helped win the silver medal in a time of 7:15.18.

[17][18] On the third morning, Heilman swam a 52.75 in the preliminary heats of the 100 meter butterfly, qualifying for the final ranking second behind Jesse Coleman of Australia.

[13] Splitting a 51.71 for the butterfly portion of the 4×100 meter medley relay, he contributed to a new Championships record of and gold medal-win in 3:36.65.

[2] Day one of three, he placed eighteenth in the morning preliminary heats of the 100 meter butterfly with a personal best time of 51.68 seconds, not qualifying for the evening final.