[1][2] She lived on a dairy farm, where she woke up at 5 a.m. each day before school to milk cows and perform other chores, such as throwing hay bales and caring for pigs.

She was named Vermont Gatorade Cross Country Athlete of the Year three times, receiving the honor in 2010, 2011, and 2012.

Her fast time in the mile marked her as a favorite to win the event at the 2016 NCAA Division I Indoor Championships.

In 2014, she won a national title in the 3000 meter steeplechase,[9] and went on to place ninth in the final of the event at the 2014 World Junior Championships in Athletics.

[15] At the 2020 USA Olympic Trials, she won the gold medal in the 1500 m with a time of 3:58.03, setting a personal best and breaking the meet record.

She finished 10th in the 1500 m.[12] At the 2022 USA Indoor Championships, Purrier won the bronze medal in the 1500 m and the gold medal in the 3000 m. She competed at the 2022 World Indoor Championships in March and won the silver medal in the 3000 m.[17] While pregnant, Purrier competed at the 2022 USA Outdoor Championships and won the bronze medal in the 1500 m.[18] She competed at the 2022 World Championships in July and did not advance to the final of the 1500 m. In February 2024, Purrier broke her own American record at the Wanamaker Mile race at the Millrose Games in New York City, running 4:16.41.

[19] In her first major international competition since giving birth to her first child, Purrier won gold in the 3000 meters at the 2024 World Athletics Indoor Championships in Glasgow, Scotland.