The talented 14-year-old Queen's High School pupil had highlighted the artistic element in her routine as a shortcoming and got to work polishing her performance.
It paid off in more ways than one. As well as winning the Mihi Aston trophy, she finished second in the junior open female grade and her school was awarded the sportsmanship Challenge Cup.
"During the heats my artistic was probably my weakest so I focused on that for finals," Christina said.
"Everyone was telling me to present to the judges more so I did that."
A promising sprinter, Christina won gold medals at the Colgate Games in the 100m and hurdles last year. Competitive aerobics is more of a sideline than the main event for her.
"It is more for fun but we are also competitive at competitions."
The teenager was inspired to try the sport when she watched a performance with her school friends two years ago. She trains twice a week for a couple of hours at a time. The routines last just two minutes but are high-energy, lung-busting events.
But to win the artistic awards it pays to smile through the pain.
Christina was not the only Otago schoolgirl to impress at the nationals. Allannah Taggart, also of Queen's, finished third.
In the junior open novice section, Gabi Pleace (Otago Girls') was second with Kerry Remon (Queen's) third.
In the senior secondary novice division, Gemma Still (Bayfield) was second. Kendyl Taiawa (Otago Girls') was third in the junior open female grade and Jade Fielding (Bayfield) won the junior secondary novice female grade.
Sian Remon, of Tahuna Intermediate, was third in the intermediate female grade, and former Queen's pupil Annelise Lowther won the adult grade.
