Anning has competed for Brighton & Hove Athletic Club since she was nine years old. From the age of 16, until his unexpected death in 2021, she was coached by
Lloyd Cowan. Anning broke the British under-15 300 metres record running 38.73 seconds and was the first, and to date, the first British under-15 to run sub 39 seconds. The previous record holder was
Dina Asher-Smith. Aged 17, she won a bronze medal over 200 m at the British Indoor Championships. A year later, at 18, she came second over 400 m at the British Indoor Championships, running 53s dead to break the nearly 50-year-old British U20 Indoor record of
Marilyn Neufville. With this she auto-qualified for the individual 400 m and the British relay squad, which won the silver medal in the
women's 4 × 400 metres relay at the
2019 European Athletics Indoor Championships. where she was coached by
Dennis Shaver. In March 2024, she won the 400 m at the
2024 NCAA Division I Indoor Track and Field Championships in Boston in 50.79 seconds, leading her teammates
Nickisha Pryce and
Rosey Effiong to an historic podium as Arkansas became the first women's program to have a 1–2–3 finish in the 400 at the NCAA Indoor meet. The
Arkansas Razorbacks, led for the first time by Head Coach, Chris 'Captain' Johnson, also won the women's team title for the second year in a row. In May 2024, Anning ran 49.51 seconds over 400 m at the
SEC Track and Field Championships, to move to third place on the British All-Time list, behind
Christine Ohuruogu and
Kathy Smallwood. At the
2024 NCAA Division I Outdoor Track and Field Championships Anning won the bronze medal over 400 m, running 49.59 seconds, in an historic race in which the Razorbacks achieved a 'super sweep' of the top four places. In the women's 4 × 400 metres relay, Anning, Effiong, Pryce and
Kaylyn Brown set a collegiate record time of 3:17.96 to win the event for Arkansas. Anning became a fully professional athlete in 2024 after graduating from Arkansas. and qualified for the
2024 Summer Olympics as a result. She was part of the
mixed 4 × 400 team which won a bronze medal in a new national record of 3:08.01. In the individual event, she reached the final and finished fifth in 49.23 seconds, a national record and only three hundredths of a second from bronze. At the
2025 European Athletics Indoor Championships in
Apeldoorn, Anning was disqualified in the 400 m heats due to lane infringements. Later in the championships she was part of the British 4 × 400 metres relay team which won a silver medal. Later that month at the
World Athletics Indoor Championships Anning became the first British woman to win the 400 metres indoor title. She ran a season's best 49.75 seconds for fifth in the women's 400m at the
Diamond League Final in Zurich on 28 August. She was selected as part of the British team for the
2025 World Athletics Championships in
Tokyo, Japan. == Achievements ==