Improving the hydrodynamic performance of swimmers during starts and turns

The Performance Sports Engineering Laboratory has had a 9 year partnership supporting the British Swimming team. We have been part of the team that helped provide success at both the London and Rio Olympics through a series of PhD students. One significant question still remains regarding how to maximise the performance during the start and turns phase of a race without adversely affecting the surface swimming phase.
Within competitive swimming the underwater phase of any race has a significant impact on the overall race time. The underwater undulating swimming technique can allow athletes to achieve higher speeds then on the surface however increases athlete fatigue due to high muscle loading whilst holding your breath.
The start and turns phase of a race also combines complex flow physics associated with the dive entry and turns which combine athlete technique with interactions with the free surface and pool walls. Understanding how each of these different elements affect the performance of the human body and overall race times is essential to minimise race time.