Federica Pellegrini ends her career in Tokyo 2020: let’s find out how science has influenced her records.
After Euro 2020, a new sporting competition has already begun: we are talking about Olympic Games. Postponed by one year due to the pandemic, the edition Tokyo 2020 it didn’t start very well for the Italian team. Following the gold of Of the Eagle In the Taekwondo, heavy were the disqualification of Pilate and the bronze missed at the last from Bertocchi-Pellacani in synchronized dives from 3 meters. Great hopes, on the other hand, are placed in the farewell tubs of Federica Pellegrini, world record holder in office in 200 meters and European in 400 meters in freestyle. The athlete’s record, now in his fifth and last Olympics, is unbelievable. She managed, at 28, to cover a distance of 200 meters freestyle in solos 1 minute, 52 seconds and 98 cents, beating the very young opponents. Neglecting any accelerations and decelerations, the speed maintained by the athlete can be approximated to 6.47 km/h. In less than half an hour of freestyle, the Divine would be able to cross it Strait of Messina: comfortable, right?
The Venetian swimmer embodies the perfect combination of talent, physicality and spirit of sacrifice. His records, however, are also the fruit of one technique perfect. Through the execution of the fundamentals of swimming, in fact, it is important to take advantage of the laws of physics, in order to avoid unwanted slowdowns.
On the occasion of the first tanks of Federica Pellegrini a Tokyo 2020 let’s analyze, with a scientific eye, what are the main factors that influence the performance of a swimmer in the lane.
It’s a question of surfaces!
The main objective of an athlete is to increase, to the maximum of their abilities, the speed of execution. To improve this aspect, it is necessary to try to limit the resistance to motion provided by the means in which the movement is made. In a nutshell, you have to decrease thefriction. This force appears between the surfaces in contact, in this case the free surface of the water and the swimmer’s body. Let’s not forget that this is partly covered by a costume and partly not. To improve the friction of the medium with the garment, it is necessary to choose a material that favors the buoyancy and that above all it is the most “smooth” e water repellent possible.
This aspect is really fundamental and what happened in 2008-2009 two-year period is proof of that. In those years, in fact, a well-known manufacturer of sports costumes patented and distributed pieces with inserts in polyurethane, born from studies of fluid dynamic nature. In fact, we began to discover the importance of aspects such as the absence of seams and the posture assumed by the athlete thanks to the plastic supports. Such garments significantly improved swim times and their spread led to a chain reaction of defeated records. Go down in history with the name of “technological doping”, These costumes were subsequently banned by the FINA and therefore will not be worn during the races of Tokyo 2020.
Also important is the reduction of friction between the athlete’s bare skin and the water. To ensure this is very simple: proper hair removal and care of the areas in contact is enough.
The power of propulsion: the secret to winning at Tokyo 2020
To ensure high speed, it is not enough just to carefully choose the macroscopic characteristics of the surfaces in contact.
A swimmer in motion, from the point of view hydrodynamic, is affected by a large number of forces due to the presence of water. Some oppose the movement by offering “resistence”To motion (such as surface and front friction). Others, for the third principle of dynamics, constitute the propulsion force of the athlete (reaction), that is, the one that makes him move. Acceleration depends on the difference between these two categories of forces and from amount of water moved during motion. For the swimmer to proceed at a constant speed, the propulsion must match the drag. In short words, the two forces must be equal in magnitude and direction, but opposite in direction.
The reaction, however, can be broken down into two components. In the direction parallel to the athlete’s movement, it coincides with the drag force. In the perpendicular direction, on the other hand, it depends on the lift, in turn defined by theBernoulli equation. The latter links the propulsive thrust to the pressure difference between the palm and the back of the hand in the stroke.
At the propulsion force the contribution given by the swimmer’s muscles must also be added, which must be minimized by exploiting the position of the body. By doing so, at the same speed, the athlete will make less effort.
After this brief and simple review of fluid dynamics, we can only wish Federica Pellegrini an exit from the scene at the height of her brilliant career. Tokyo 2020 it is, in fact, the last chance to raise the bar of his record. Faith, may the driving force be with you!