The current Airshield, complete with go-kart, is a prototype, born of a request from the coaches of the Swiss sprint team, which includes Frey and reigning European champion Mujinga Kambundji. The hope was that ETH Zurich could develop drag-reduction equipment to help top sprinters train and, ideally, improve their performance in competition. The result is a project that brings together science, sport and technology. At its helm are Zeilinger and ETH professor Emilio Frazzoli, who developed the go-kart used to pull the Air?shield. Researchers from the Institute for Dynamic Systems and Control at ETH Zurich developed an algorithm that automatically matches the speed of the Airshield to that of the sprinter. A more recent addition to the team is ETH professor Christina Spengler, a health science specialist who is looking at the new training system from the perspective of sports science.
In the stadium, meanwhile, temperatures are still rising. While workers hose down the empty stands with water, Frey and her two teammates begin their warm-up routine – an essential precaution to prevent injuries, even at 30 degrees Celsius.
Career athlete and student
Frey has been mad about sport ever since junior school. Her focus on athletics came later, while at secondary school in the Swiss town of Zug. Although sorely tempted to turn professional, she was wary of committing herself entirely to a sporting career. To keep her options open, she chose to study pharmaceutical sciences at ETH, progressing to a Master’s programme after finishing her Bachelor’s degree. “ETH is a sport-friendly place and very accommodating about me being in the national squad,” says Frey. “I really value that.” If all goes according to plan, she will complete her Master’s degree next year. Before then, however, she aims to give her all in preparation for the Paris Olympics.
Trackside, Christina Spengler is busy setting up her equipment on top of a vaulting box. A video on her laptop shows how Frey and the Airshield become synchronised. “When she sets off, the go-kart also starts moving, but at this point the Airshield is still travelling more slowly than the athlete,” explains Spengler. “A sensor in the Airshield registers this difference in speed, and the go-kart accelerates accordingly.” Based on Frey’s speed and her distance from the Airshield, an algorithm calculates the precise acceleration required to maintain an ideal gap. In other words, the speed of the go-kart is controlled automatically. All the driver does is steer.