Muir had the option of contesting both the 800m and 1500m events in Tokyo but made the “very hard decision” to drop the shorter distance; opened up on why she decided to stay with 1500m in an interview with the BBC.
“Two events was the original plan, but what I really want is a medal and the level of competition is so intense in the 800m,” she said.
“I know I can be up there, but I’d hate to be mediocre at both and, while it was emotionally a tough decision to make, mentally it was clear to me that the 1500m is where I needed to be.”
None of those who won medals in the event at Rio 2016 will compete at the postponed Tokyo 2020 Games and Reekie is among a group of emerging middle-distance runners hoping to make their mark in Japan.
“There are so many young ones in the sport who have come through and the extra year has helped us progress and learn,” the 23-year-old Scot said.
“It’s a whole new set of athletes looking to progress, but I know I’d be disappointed if I didn’t reach the final – and I’d also be really disappointed if I didn’t make the podium, so I have high expectations of myself.”
Muir and Reekie are among 12 Scottish athletes set to compete as part of the 72-strong Team GB track and field line-up in Japan.
On her intention to improve on her seventh place at Rio 2016 and has fourth and fifth in each of the last three World Championships.
“I keep getting so close and it’s so hard, but I know it’s in me,” Muir told BBC Sport.
“Hopefully, when you get one then all of a sudden they start to come. There’s a lot of major events backed up for next year and to kick it off with an Olympic medal would be brilliant.”