In a matter of minutes, Lucia Stafford began her 2023 track running season indoors with two personal-best times, including a Canadian record in the 1,000 metres.

While the process to achieve this level of success took years, she has witnessed dramatic improvement in her results the past 18 months.

Often consumed by the outcome of her races, Stafford stopped worrying about time or other runners in her 2020 Olympic debut, focusing on each lap and being present in the women's 1,500.

"If you focus on executing every lap the way you want, feeling strong and making sure you do your best … you should run fast and place high," Stafford said this week from her Toronto residence before flying to New York to race the indoor mile in her Millrose Games debut on Saturday.

The Tokyo Olympics, delayed a year by the COVID-19 pandemic, was "a huge learning experience" and turning point in Stafford's athletic career.

"I grew a lot in the mental game, [how to handle] pre-race nerves and anxiety," said last year's Canadian champion in the 1,500. "Once the [start] gun went off in my heat and the semifinals, I felt like my body knew what to do."

Stafford delivered a 4:03.52 PB on Aug. 2, 2021 to qualify seventh for the Olympic semifinals ahead of her older sister, Gabriela DeBues-Stafford, who holds a combined seven indoor and outdoor records. Two days later, she ran over a second faster in 4:02.12, 43-100ths of a second shy of Spain's Marta Perez, who grabbed the last qualifying spot for the final.

"I went from a 4:05, 4:06 runner to Olympic semifinalist and almost Olympic finalist," said Stafford, "and I honestly think it was purely because of my mindset."

Stafford remembered when she almost felt intimidated by her own drive, competitiveness and expectations that would cause her to dread racing.

"I wanted to do well and knew I could but was so scared of letting myself down," the 24-year-old recalled. "I've changed a lot in many ways in the last year and the approach to racing is definitely a big one. Now, it's more of an excitement for the opportunity to show off how hard I've worked."

Since returning last March from a four-month stint with Bowerman Track Club in Oregon, Stafford has built confidence, developed more trust in herself and is better prepared for competition.

She trains twice a week at the University of Guelph with Terry Radchenko, her coach since age 12, and at the Athletics Canada East Hub (Toronto Track and Field Centre) at York University.

"She's continued to improve by adding to her training [as far as] volume and intensity," said Radchenko, head coach of middle-distance runners and cross-country at Guelph. "[At York] she can see a sports medicine doctor, chiropractor and nutritionist, and get physio and massage treatment, so she's doing all the things to compete at the highest level."

Stafford has also fulfilled her desire for a balanced life by spending time with friends away from the track and is enrolled in the singer/songwriter program at Seneca College.

Brit Townsend, head coach of track and cross-country at Simon Fraser University in Burnaby, B.C., was in Boston with her athletes on Jan. 28 and watched Stafford's record performance in the 1,000.

"She was the best I've seen her as far as how strong and confident she looked," Townsend, who represented Canada in the women's 1,500 at the 1984 Olympics in Los Angeles, told CBC Sports. "She's reaping the benefits of having a healthy body and that makes a big difference mentally."

In high school, Stafford was diagnosed with Graves' Disease, an autoimmune disease in which your immune system attacks healthy tissue in your thyroid gland at any time for unknown reasons.

"She had some [health] challenges a couple of years ago which is under control now," said Townsend. "She believes she can achieve everything but is also humble, and that's a good combination."

In Saturday's mile scheduled for 5:41 p.m. ET, Stafford will face reigning Olympic 1,500 silver medallist Laura Muir, U.S. 1,500 champion Sinclaire Johnson, and British indoor mile record-holder Jemma Reekie.

After running ahead of the field to a 4:23.52 PB in the mile on Feb. 4 at the New Balance Indoor Grand Prix in Boston, she noted the Millrose field is deeper with more top-end talent.

"I don't have as much experience being one of the top dogs in a field like that," Stafford said of the Boston mile. "Coming to these meets as a contender now is very different than what I'm used to, but it's cool."

With World Athletics allowing athletes to use mile times to qualify for the outdoor 1,500 at the Aug. 19-27 world championships in Budapest, Hungary, Stafford will be eyeing the 4:22 automatic entry standard on Saturday.

DeBues-Stafford holds the Canadian women's mile record of 4:19.73 from the 2020 Millrose Games.

"It'll have to be a perfect day for that to happen, but you never know," Stafford said. "I'm excited and curious."

Sarah Mitton (shot put) and Michelle Harrison (60 hurdles) are the other Canadians competing at the 115th Millrose Games, an iconic track and field meet held at The Armory in Manhattan.

On Jan. 13, Mitton threw 19.40 metres in the opening round at the Can/Am Classic in Windsor, Ont., to raise the 19.16 national indoor mark she set last Feb. 5 in New York. On her sixth and final attempt, she improved to 19.80.

The 26-year-old from Brooklyn, N.S., has since competed three times, topping out at 19.29 on Jan. 31 in the Czech Republic.

Saturday's four-women event at 4:28 p.m. is headlined by American Chase Ealey, the 2022 world champion who won the Diamond League Trophy in September with a best throw of 20.19 (20.21 is her personal best). The 28-year-old beat Mitton three times on the professional track and field circuit, but her 2023 best of 18.61 is a metre lower than the Canadian.

WATCH | Mitton rides 19.56m throw to 2nd place in Diamond League Final:

Harrison of Saskatoon is the first Canadian in action Saturday at 4:03 p.m. Like Stafford, she competed at the Indoor Grand Prix in Boston, placing sixth in 8.10 seconds (her PB is 7.49).

At 29, she experienced a breakthrough last season, clocking a 12.74 PB in the world 100 hurdles semifinal and placing 14th overall in Eugene, Ore. After winning a second straight Canadian title, Harrison finished eighth in the final at Commonwealth Games and fifth at the NACAC Championships in Freeport, Bahamas.

WATCH | Harrison advances to world 100m hurdles semifinals: