She also receives specialist coaching from Jeremy Tigar in the throw disciplines (shot put and javelin), Richard Aspden in the high jump and Ian Grant in the hurdles.

In February 2014, Lake competed in an indoor athletics event in Vaxjo, Sweden, where she broke the World U18 record for the pentathlon, improving Carolina Klüft's score of 4261, with 4284 points.

[8] In July 2014, Lake and her coaches initially planned to have her compete in the Glasgow Commonwealth Games, but decided against it and headed for the 2014 World Junior Championships in Eugene, Oregon instead.

[2] She began her campaign at the championships on 22 July with the 100 m hurdles, finishing 12th overall with a time of 14.29 s.[9] She stormed to the top of the heptathlon table with 2096 points, setting a British junior record of 1.94 m in the high jump.

[11] She closed the day with the 200 m, finishing in third place behind German world youth champion Celina Leffler and Dutch athlete Nadine Visser to end with a total of 3821 points and remain at the top of the heptathlon table.

[14] Lake then closed the day with a seventh-place finish in the 800 m with a personal best time of 2:21.06, but secured the gold medal with a final total of 6148 points, ahead of Cuban Yorgelis Rodríguez and Visser.

[16] In August 2016, Lake competed for Team GB at the Rio Olympics in the individual high jump event, achieving a personal best of 1.94 m and reaching the final.

A month later, she won a silver medal at the Commonwealth Games, with another clearance of 1.93 m. Lake was selected to represent Great Britain at the 2019 World Athletics Championships in Doha, Qatar.

[18] She also finished second in the indoor competition with 1.84 m. In 2021, Lake once again won the British Championships with a leap of 1.93 m. At the postponed 2020 Tokyo Olympics, she qualified for the final with 1.95 m but withdrew due to injury.

[19] After winning the high jump gold medal at the 2024 British Athletics Championships, Lake was subsequently named in the Great Britain team for the 2024 Summer Olympics.