In the cement quad of a school ringed by double fences and patrolled by guards, a dozen teachers and their principal get ready to sweat in the Cape wind.
Bouncing on her feet, principal Ruschda O'Shea is unconcerned about how she will look running laps in her Springbok T-shirt, worn in memory of Joost van der Westhuizen.
She jokes with her staff as they prepare to take a 12-minute "motion" test for the Teachers on the Move programme, run by the Sports Science Institute of South Africa.
This is the final afternoon of a six-month intervention to help teachers become healthier and more active.
Before the activity, biokineticists provide free cholesterol, blood glucose and blood pressure testing, and take the teachers' weight, hip and waist measurements - a weekly service to assess their progress.
Their coach, Veronica Plaaitjies, 64, counts down as the eight women and four men get ready. Then they are off, with teachers Berenice Moss and the drillmaster Selwyn Lewis among those up front.
Most run the whole time but some, including O'Shea, walk at intervals. She has joined every session she could but meetings have cut into her attendance.
Her school in Mitchells Plain has more than 1,100 students. Dagga use, smoking, gambling, teenage pregnancy and HIV infection are challenges at Tafelsig High, in an area where gang violence is common.
"My school was described as a pipeline to the prisons and we need to break that. I encourage organisations like Childline, the Quaker Peace Centre and Soul Buddyz to come here, and I promote sport like crazy. We have to give our students alternatives," said O'Shea.
"My teachers range from 38 to 69 years old and they are stressed. This is something for them which makes them feel good. It also brings me closer to my colleagues and we have fun.
"One of them has stopped smoking. Another one brings healthy lunchboxes to school. They are drinking water."
After running, the teachers nominate two of their group to be trained to continue the exercise programme.
Zulfah Gierdien-Abrahams, project manager for the institute's community health programme, said they wanted to leave a legacy.
Teachers on the Move has trained two batches of schools so far.
The first four schools started in September 2015, and 53 teachers completed the programme. Their blood pressure came down, waist and hip circumferences decreased, and body mass indices improved.
On average, the teachers lost 5.3kg over the six months.
The latest batch, including Tafelsig, have also had positive results. Eighty-seven teachers who completed the programme improved all their scores.
Cape Town school sport consultant Ebrahim Moerat has found another way to boost sport at school. While he was head of sport at Groote Schuur High, he and colleagues transformed the mindset there. "We included sport in the school day by lengthening the day by 40 minutes," he said. "Initially there was some resistance from teachers ... but this changed and a new culture emerged as they saw the benefits."