BOULDER, Colo. — Looking to shave five minutes off your next marathon time? Then try running right behind another competitor to avoid wind drag, new research confirms.
Marathon runners can increase their power by six percent per one percent of their body weight in the absence of wind resistance, according to the findings in the Journal of Applied Physiology. Using a technique called “drafting,” where a runner shields themselves from the wind by pacing themselves directly behind someone else, a competitor can ideally eliminate about 85 percent of drag. Even slower or moderately-paced runners can trim nearly four minutes off their marathon times by drafting, researchers at CU Boulder say.
“Our study confirms that drafting can make a huge difference,” says senior author Rodger Kram, an associate professor emeritus at CU Boulder’s Department of Integrative Physiology, in a university release. “Even elite marathoners are not taking full advantage of this.”
Who came up with ‘drafting’?
The benefit of drafting during competitive races was first touted in 1970 by British physiologist Griffith Pugh, who concluded that runners exert eight percent of their energy just by pushing against air. Runner forums and marathon blogs still debate the scientific data behind Pugh’s conclusion that elite marathoners can shave six minutes off their time through sophisticated drafting. Pugh’s study only involved one runner on one treadmill inside a wind tunnel.
Kram joined two other researchers, Edson Soares de Silva of the Universidade Federal do Rio Grande do Sul in Brazil, and Wouter Hoogkamer from the University of Massachusetts Amherst, to test Pugh’s controversial drafting claims.
They tasked a dozen male runners with completing six five-minute trials on a treadmill, running between a six to eight-minute mile pace. The study participants first ran those trials normally before having rubber straps attached to the participants’ backs which pulled them at either four or eight newtons of force. This weight equivalent of two full beer cans “reliably measures” the aerodynamic drag of running with a pacer. Kram and the team also measured the runners’ oxygen consumption and levels of energy during each trial.
The UC Boulder team ultimately concludes that Pugh’s 1970 drafting data was right. An elite marathon runner such as Kenya’s Eliud Kipchoge can potentially reduce their time between 3:42 and 5:29, the new research corroborates.
“Our number ends up being very similar to what he found with that single runner,” Kram says.
“Anyone from top elite to lower-level marathoners could benefit from adopting the optimal drafting formation for as much of their race as they can,” adds da Silva, noting that a 5-foot-7 female runner at 125 pounds could shave five minutes off her three-hour, 35-minute marathon time by drafting.
Drafting can help — but is it legal?
But be careful, runners — drafting, also sometimes referred to as “sandbagging” in runner pejorative, is a practice which can get you disqualified.
In October 2019, 34-year-old Kenyan runner Eliud Kipchoge became the first person to run a sub-two-hour marathon, clocking in at one hour, 59 minutes, 40 seconds. He essentially sprinted the entire race at a 4:34-mile pace, the equivalent of running the length of a football field in 17 seconds 422 times in a row.
However, Kipchoge’s record-setting marathon feat is not honored by the International Association of Athletics Federations (IAAF) because he used a rotating team of pacesetters at the Ineos 1:59 Challenge race in Vienna. This phalanx of pacesetters allowed Kipchoge to draft off what looked like a human shield against the wind. Five pacesetters formed a V-shape and two runners nipped right at Kipchoge’s heels in order to reduce the wind drag and keep him motivated.
These pacesetters rotate on and off the course during the marathon, a move forbidden by official rules. In addition to drafting in order to gain a competitive edge, Kipchoge also had cars using lasers to guide him along the least steep parts of the road.