Originally published on SwimSwam.com
While swimming freestyle, the positions of least frontal drag do not necessarily correlate with the positions of maximum propulsive power. Head position is just one example of this conflict. When the head is in alignment with the body and the spine is straighter, the least frontal drag is encountered. Yet, to maximize the power of the underwater pull, the lower back should be arched some, which results in an elevation of the head.
With some of our freestyle swimming motions, such as the underwater pull, we need to choose between more powerful force and lesser drag positions and often compromise between them. Not so with the head position.
Because of the exponential relationship between frontal drag and speed, the most important time to have the lowest drag coefficient is when our body is moving the fastest within the cycle. That occurs precisely when one hand first enters the water. It is at that point that it is most critical to have the head down.
Two beneficial events happen when we tuck the head down at the hand entry. First, the bow wave goes over the top of our head, essentially putting the head underwater for a brief moment. There is less drag underwater than on the surface. Second, our body straightens out more, creating a better shape to surge forward.
Elite freestylers, such as Phelps, Sun Yang or Katie Ledecky, create a noticeable surge in speed with the head down right after the breath, accompanied by a strong propulsive kick. It is easier to do this with the slower stroke rates of the hip-driven or hybrid freestyle, than with the faster stroke rate of the shoulder-driven freestyle. Yet it works with any freestyle technique.
Once the hand is under water, about one foot in front of the shoulder, initiating the propulsive phase of the pull (when the hand starts moving backward), the body must change its shape slightly in order to increase power. One cannot maximize the force of the underwater pulling motion without arching the lower back, which also causes a small lift of the head, similar to initiating a pull up from a bar.
If one were to be able to see the movement of the spine as an elite freestyler propels down the pool, one would see a shift from a relatively straight spine to a slightly arched lower back with each stroke cycle, over and over again. This movement enables the swimmer to take advantage of both the power position and the least frontal drag position.
The real question is, if swimming with the head down is conducive to faster swimming, why is everyone swimming with the head up? The answer is defensive swimming. Within the environment of a crowded workout lane or a frenzied swim at the beginning of a triathlon, swimmers are watching out for themselves, looking forward, hoping to avoid an unnecessary collision. In a crowded pool, lead the lane or go 10 seconds behind, stay to the right and pray, but keep your head down. Once you are in a race, where you are given your own lane, or after finding your space in an open water swim, you have no excuse. Get the head down when the hand enters the water and enjoy the surge.
Yours in Swimming,