Can Faith Kipyegon break 4 minutes in the Mile?
"I appreciate people taking my world record performance as an inspiration to imagine what could be possible in the future."
By Jonathan Lambert, NPR
Three-time Olympic champion Faith Kipyegon is really, really fast.
In 2023, the Kenyan middle-distance running superstar set three women's world records, including running a blistering 4:07.64 for the Mile, breaking the previous record by 5 seconds.
Track fan and biomechanist Rodger Kram was watching that race, and something about how it played out stuck with him.
"The runners who were her pacemakers ran out too fast and there was a gap between her and her pacemaker," he says.
Pacemakers help set a fast pace, and act as a barrier to the wind, making the race easier for the runners behind them — but only if they're close.
"So she really had pretty poor aerodynamic drafting when she broke the record," says Kram, of the University of Colorado Boulder. "That got us thinking that maybe if we improved drafting and reduced the force that the air exerts to slow you down, whether she could break 4 minutes."
Kram and his colleagues are no strangers to such schemes. They predicted, and then helped plan, Eliud Kipchoge's sub 2-hour marathon in 2019, where he was precisely paced to 1:59:40 by a rotating team of runners who ran in front of him for most of the race. That setup helped Kipchoge run faster than anyone ever had, and his colleagues wanted to see if something similar could work for Kipyegon.
Theoretically, it could. With pitch-perfect pacing both in front of and behind Kipyegon, she could run 3:59 for a Mile, researchers reported this week in the journal Royal Society Open Science.
"I'm sure people are going to say no way, women can't run under 4 minutes," says Kram. But he notes that people thought it was physiologically impossible for men to run that fast until Roger Bannister did in 1954.
Predicting sub-4
On a basic level, running requires burning energy to power forward movement. How much of that energy gets translated to forward motion depends on a variety of factors, from running form to wind resistance. Kipyegon's form is already near-perfect, but drafting behind a pacer could allow more energy to go towards running fast.
To figure out how much faster Kipyegon could run, they first calculated how much energy she burned for each lap of her record-setting Mile. Then, they used aerodynamic models to calculate how much faster she could run with drafting.
"We looked at several different formulations of drafting," says Shalaya Kipp, a biomechanics researcher now at the Mayo Clinic. "One scenario was if she ran in a vacuum, with no air resistance at all."
In that hypothetical scenario of 100% drafting effectiveness, Kipyegon could run 3:53, the researchers found. The researchers considered more realistic scenarios, where Kipyegon had pacers for two, three and four laps.
The sweet spot turned out to be having two pacers, one in front and one behind Kipyegon for the entire race. In that scenario, the reduced air resistance would allow Kipyegon to run 3:59.37.
"If you have just one running in front, you get about a 70% drafting effect," says Kram. "But if you have one in front and one behind, you get about 75% … the runner behind is pushing air molecules essentially against the back of the runner in front of them."
When Kram saw 3:59.37 pop up for this scenario, he was surprised. "That's exactly the same time Roger Bannister ran."
Continue reading, including audio clip, at: npr.org
Mile world record progressions HERE.
