While swimming freestyle, there seems to be an ongoing debate as to where the proper head position should be. There are many world-class swimmers that do very well looking forward slightly as they plow through the water. I use the term plow because, in fact, these swimmers are constantly pushing against a bow wave, plowing against their heads. Yet they manage to do just fine.
There are other world-class freestylers that also manage to get their heads underwater, looking more straight down, particularly at the crucial time of hand entry into the water. Should the line of site be straight down or slightly forward? Which swimmers have it right? Well, they probably both do.
When we discuss head position, there are two conflicting forces that must be considered; the forces of frontal drag and the forces of propulsive power. They are both important and they often don’t agree. It turns out the best head position to maximize propulsion will also increase frontal drag. The best head position to minimize frontal drag will reduce propulsive power. As is the case with so many of the swimming stroke mechanics, the ideal head position involves both compromise and timing.
The two most important factors in determining how much frontal drag we create while swimming are the surface area moving forward and the speed of our body or body parts. While the surface area is linearly related to frontal drag force, a swimmer’s velocity is exponentially related (the square of the velocity) to frontal drag. For this reason, the faster one swims, the more technically correct one needs to be. Very small increases in speed with the wrong position result in huge increases in frontal drag.
The fastest point in the stroke cycle is when one hand just enters the water and the other hand is completing the propulsive phase. At this moment, the swimming body is in the most streamlined position that it is going be in while still pulling and kicking. At this moment, it is particularly important for the head to be in the down position with the body aligned and even better for the head to be slightly under water, so the bow wave passes over the top of it, eliminating surface drag.
Once the propulsive phase begins and the hand starts to move backward (the hand is approximately one foot in front of the shoulder), it is important for the body to be in the best mechanical position for the strongest pull. That position is when the back is arched slightly and the head is tilted forward slightly. Just as if one were doing a pull up on a bar, the maximum force can be achieved with the lower back arched. Fortunately, since this moment occurs between .3 to 1 second after the hand enters the water, depending on the stroke rate and technique, a swimmer has time to change his/her head position from down to slightly tilted forward and achieve the best positions for both frontal drag and propulsion.
When a breath is taken, the head is rotated and lifted, creating some additional drag, but it is often after the breath stroke that the head is buried underwater, particularly with a hip driven or hybrid freestyle technique. In my opinion, it is a mistake to keep the head in the tilted-forward (power) position all of the time, causing more surface or wave drag. It is also a mistake to keep the head in the down position during the propulsive phase, reducing the power of the pull.
In both backstroke and in freestyle, the fastest swimmers will shift their head position to be in the best position for each of these crucial times. If one were to look at the lower back of the swimmers, one would see a constant change from straight to arched and back again, over and over again…timed perfectly with the hand position in the water. These swimmers are doing mini-crunches in the water. Yes, another good reason to do those dry land exercises!
Yours in swimming,