The "dance fit" class, part of the school's healthy lifestyles agenda, was led by a sixth-former. Each session began with a workout followed by different exercises. And each session was recorded on video so pupils could watch their performance.
Cleo Chater-Davies, head of PE, said: "Pupils had the opportunity to express themselves through dance. They were encouraged to use their imaginations to create parts of the dance while working individually, in pairs or in groups."
Mrs Chater-Davies monitored pupil performance before and after the sessions, noting improvements in problem-solving, communication, team-working skills and creativity.
Dr Schmit said: "It is a type of study-support activity that is common in Cardiff schools. It shows that even what might be classed as a leisure activity is evaluated to ensure that it is benefiting the pupils."
However, no boys signed up for the classes, which attracted around 15 girls aged 11 to 17 each week.