A group of swimming researchers say the structure of the Olympic pool have may given unfair advantages to athletes who swam in higher-numbered lanes, according to The Wall Street Journal. Joel Stager, a director of Indiana University’s Counsilman Center for the Science of Swimming, says he and his team have run calculations that suggest swimmers who swam in the 50-meter freestyle in lanes five through eight received a slight speed boost. Meanwhile, those in lanes one through four suffered about a half-percent drag on their times. In swimming, even tiny fractions of a second can keep participants from the podium.

According to Stager, the issue stems from a design flaw in these types of world-class pools, which were constructed by a company called Myrtha for both this year's Olympics in Rio de Janeiro and the 2013 world championships in Barcelona. Three years ago, Stager's team documented a similar effect during the Barcelona contest. It turned out the pool was creating currents that aided higher-numbered lanes in one direction and lower-numbered lanes in the opposite direction. The findings were published the following year in the journal Medicine & Science in Sports & Exercise.

Now, Stager's team says the design of the pools in Rio have again compromised the sport's results. The researchers point to the fact that, of the eight men and eight women who participated in the 50-meter freestyle, all but one swam in lanes five through eight. Those who swam in those lanes early on in the preliminaries or semifinals and then switched to lower-numbered lanes for later heats suffered slower times, as well. In the finals, Stager points out that five of the six medalists swam in lanes four through eight.

"It’s a big deal. This is horrific," Stager told the WSJ. When the team's research was released in 2014, a Myrtha representative reportedly said "the times would say there was" a current in the pool in Barcelona. In both cases, Myrtha built so-called temporary pools, which are built before and then broken down after a competition. A separate paper published by Stager's team in March of this year found that time discrepancies could be linked with temporary pools more so than permanent pools.

Myrtha Chairman Trevor Tiffany told the WSJ that its officials tested the pools in Rio for currents using a large jug, both before and after races. "We were required to do tests to show that there was no movement of water, and the tests were conclusive that there was no movement of water," Tiffany said. "If we saw there was a current, we’d have done something about it." It's unclear at this time how FINA, swimming's governing body, or the International Olympic Committee will respond.