North St. Paul senior Isaiah Koran keeps a busy schedule. After school this past week, he went directly to track practice, followed by rehearsal for the school play that opened Thursday, then to the weight room for his regular workout, arriving home about 10:30 p.m.

The load has recently increased, too. Koran took on a captain's role on the track team this season in hopes of replacing star sprinter Akeem Sirleaf, who graduated last year as a three-time state champion in the 200-meter dash.

Polars track coach Todd Wallert, who has led the team to 11 consecutive conference titles, said Koran takes it all in stride.

"His work ethic has really separated him from everybody else, and Akeem was the same way," Wallert said.

"The expectation is, 'Now it's my turn to lead, it's my turn to be that guy.' … He's one of our team captains, and the kids vote on that. They just really see him being the next guy that steps up and is our leader."

Koran, who competes in the long jump and in a combination of sprints and relays at each meet, said watching Sirleaf's work ethic and success throughout his career inspired him to step up this season. Koran was on the 4x200 relay team with Sirleaf that placed second at the 2015 state meet.

"More than anything, he just taught me how to have a competitive attitude in everything that we did," Koran said. "Whether we were doing block starts, running 200s, we could be stretching, we could be in the weight room. It didn't matter what we were doing, it was always a competition. And it not only raised the level of our performance, but it raised the level of everyone around us, too."

Koran will have a familiar face by his side this season. Wallert said senior Bishop McDonald, Koran's friend and teammate on the Polars football team last fall, has also grown into a leadership role in track. McDonald competed in the relays with Koran and Sirleaf last season while also running hurdles.

"[Bishop] kind of popped on the scene last year," Wallert said. "[After] his time in the weight room and his work ethic, suddenly last year we thought, 'Wow, he's got to be on our relays because he's gotten that much better.' … Bishop has really come a long way."

On the football field, Koran and McDonald led North to its first section title last fall in 27 years.

Koran finished the regular season rushing for an average of 101.9 yards per game. McDonald rushed for an average of 64.3 yards per game during the regular season and had 12 interceptions. Both signed letters of intent to play at Minnesota Duluth in the fall.

McDonald said Koran "always motivates me just to get faster because I always want to try to beat him. And I'm just motivating him on the conditioning days, making him work harder, making him get better, too."

Koran said the football team's newfound success in the fall, especially after the team started the season 0-2, motivates the duo to end their Polars careers on a high note on the track as well.

"It would be the icing on the cake," Koran said. "We lost a lot of guys in track and a lot of people are probably doubting us this year. … But a lot of key guys on the track team are football players so we know what it's like to be up against those odds."

Despite his often-busy schedule and the pressures of filling Sirleaf's void, Koran is focused on becoming a state champion on his own terms.

"There'll never be another Akeem Sirleaf, but I have to do my best to fill the role that he filled and I have to be that leader on the team," Koran said.

"I'd like to be a state champion in the 200, maybe long jump, and every event possible that I can compete in. … I want to go out and prove myself."

Kaitlin Merkel is a University of Minnesota student on assignment for the Star Tribune.