This is the only deadline to qualify for the Paris 2024 Olympic Games. The French swimming championships will take place in Chartres from this Sunday June 16 until Friday June 21, where the French swimmers participating in the different events will be designated swimming this summer.
Every hundredth of a second counts in this discipline, where world records continue to fall. Progress particularly linked to the evolution of Olympic swimming pools which have become “increasingly efficient”underlines Rémi Carmigniani, researcher at the École des Ponts ParisTech.
Swimming has been one of the Olympic disciplines since the start of the modern Games in 1896, but the competition was initially held in “open water”, like certain events planned for this summer in the Seine. The first Olympic pools appeared during the 1908 Games in London.
Deeper therefore faster?
An Olympic swimming pool was then 100 m long, 15 m wide, and accommodated four swimmers. These pools “weren’t very fast”recalls the researcher because “The swimmers were relatively close together and there was no separation or chutes. So there was a lot of turmoil”.
The depth at the time was barely 1.40 m at the end of the basin. However, the evolution of this data is one of the factors which has made it possible to improve the performance of Olympic swimming pools. Its change was in fact accompanied by records: in 1932, in Los Angeles, when the pools reached a depth of 2 m, “ten Olympic records were broken in eleven events contested”recalls Rémi Carmigniani.
A “huge progress” linked to a greater depth which reduces the turbulence of water bouncing at the bottom. Today, the depth of an Olympic pool established by the International Swimming Federation (FINA) is a minimum of 2 m; it is even recommended that it reach 3 m.
Gutters, water lines… Devices with relative effects
Stabilizing the water turns out to be an important factor in improving the performance of a pool, and therefore that of swimmers. Gutters were added to the edges from 1976 “to absorb the waves”, says Rémi Carmigniani. The corridors on the sides were then considered “unfavorable” for the swimmers, because they bounced the waves in the pool.
But the addition of gutters does not change much for the Olympic events because of their specificity. At the Olympics, the two exterior lanes are closed so as not to penalize the swimmers, because the wave phenomenon cannot be entirely broken by the presence of the gutters.
Water lines, these chains of plastic floats, are also present in Olympic swimming pools today to dissipate the waves generated by swimmers. “The goal is that there are no more waves in the lane when the swimmer returns in the other direction”specifies Rémi Carmigniani. “But it is not true to say that water lines make all races fair. »
Indeed, the water lines do not allow the phenomenon of “drafting” to be completely eliminated: in 2008, Alain Bernard lost the 4 × 100 m relay against the American Jason Lezak who was riding his wave. Four years later, it was the turn of Yannick Agnel who won the relay after taking advantage of the wave of his American competitor Ryan Lochte. “The water lines do not yet make it possible to make each lane independent to have a race without interaction”concludes the researcher.
Improve swimmer performance
Helping swimmers to swim faster means allowing them to gain more speed, particularly thanks to the starting blocks. Raised diving boards appeared for the first time during the Berlin Olympic Games in 1936, and have since been constantly evolving (material used, inclination). The last modification dates from the 2008 Beijing Games, when an inclined plate, like the starting block wedges in athletics, was added, allowing swimmers to place their back foot there to improve their support.
Another important element, the turn and its push on the wall. Its importance has been known for a long time, says Rémi Carmigniani. During the 1932 Olympic Games in Los Angeles, during the 400m freestyle event, Frenchman Jean Taris “was caught at every turn by an American Clarence Crabbe”, he explains. Result: he missed the gold medal by a tenth of a second. If the push to the wall “made it possible to accelerate the swimmers in the turns”he notes, “the French took time to master this technique at the time”.
Finally, the question of water temperature is also decisive in optimizing swimmers’ performance. This is why the thermostat of an Olympic swimming pool displays precisely 26 degrees. While this may seem cold to those who are cold, this temperature offers swimmers better water viscosity, allowing them to swim faster thanks to less resistance.
