Unlike in cycling, athletes pay little attention to aerodynamics, and take to the track with unbound hair and sometimes flowing outfits. A scientific study on women's long jump shows that these choices have a real influence on performance.
These are images that startle cycling fans and followers of the Tour de France, where every detail is scrutinized in terms of aerodynamics, from the shape of the helmet to the height of the socks: since the start of the Olympic athletics events, as they traditionally do, male and female sprinters have been showing up with exuberant hairstyles, jewellery around the neck or wrists.
In an article we published in 2022, Emmanuel Brunet, research and performance manager at the French Cycling Federation, explained: "In cycling, sailing and speed skating, it's crucial. In athletics, an unsuitable outfit, round jewellery or hair that gets caught in the airflow can cost a few hundredths." A few hundredths or a few centimetres, but how much exactly?
Up to 10 centimetres difference in the long jump
Dutch aerodynamicist Bert Blocken has set out to answer this question. Already involved in wind tunnel research on cyclists for many years, this time he led a study into the influence of haircuts and clothing in athletics, and more specifically in the women's long jump. The findings were published online on July 26, the day of the Olympic opening ceremony: haircuts can increase an athlete's aerodynamic drag by 8.7%. For clothing, drag can vary by 27.9%. In concrete terms, this could represent 10 centimetres in the long jump.
The researchers focused on the long jump, since flight time is a major factor in performance, accounting for 90% of the jump's total distance. In the air, only gravity and aerodynamic forces influence the athlete's body, the study points out. Visually, the researchers noted the variety of hairstyles: from tightly tied-up hair to dreadlocks to curly hair let loose. They also wrote of their surprise at the clothing styles, with outfits more or less close to the body, sometimes flapping in the wind, and bibs often fastened with pins.
Full-body suits for all sprinters?
The results confirmed the premise: long, loose curly hair increases aerodynamic drag by 8.7% compared to an athlete with a shaved head. Even hair tied up in a bun behind the head has an impact: +2.3% for drag. Clothing choices have an even greater impact, especially shorts: 27.9% difference in drag between tight-fitting shorts and very wide shorts. According to the study, these variations have above all an impact on jumpers' take-off speed. And the findings should be of interest to all sprinters.
The study's conclusion is clear: athletes have everything to gain by wearing wind-tunnel-tested outfits and switching to full-body suits that cover the head in particular. "
Athletes who make this choice can gain considerable advantages over their opponents", summarize the researchers. This cultural revolution could take years, if not decades, according to the study's authors, who stress the " rather conservative nature of athletics disciplines". They point out, however, that an athlete like Cathy Freeman figured it all out as early as 2000, when she won the 400 m at the Sydney Olympics in an explosive full-body suit.
(L'Équipe)