How to Breathe While Swimming: Air Lubrication System

Quick and Shallow

First, I want to dispel one myth about breathing during intense exercise. In no sport does an athlete ever take a complete inhalation or expiration. The breaths during intense exercise are relatively quick and shallow, meaning that a little O2 comes in and a little CO2 goes out with each breath. It is an air exchange, not a deep breath.

The most detrimental part of breathing in swimming is likely not the associated increase in frontal drag, though that can be significant, depending on how the breath is taken, but rather the slowing of the stroke rate. Particularly in shorter races, a long, ‘star-gazing’ breath that slows the stroke rate can have disastrous consequences for both speed and inertia. To help with stroke rate and frontal drag, getting the breath quickly and with the least amount of change in body position is vital. In freestyle, that means turning the head minimally (keeping one goggle lens in the water during the breath), elevating the mouth to one side to meet the air, and rotating the head posteriorly (backward) rather than straight to the side or forward.

In butterfly, it means extending the neck forward maximally for the breath, keeping the mouth close to the water, while maintaining the body in a more horizontal position. Or in cases where swimmers can’t seem to avoid lifting the shoulders too high for the front breath, breathing to the side in butterfly may be a better option. It is important to be aware of these details in order to effectively develop an air lubrication system while swimming fast!

Hold or Let Go?

While in land-based sports, the inhalations are immediately followed by expirations and vice versa, or, in other words, there is no ‘breath holding’, in swimming, there may be a theoretical advantage in doing so. On land, our weight does not change appreciably with each breath, but in the water it does. The weight of a swimmer ranges from zero with the lungs inflated to around 8 lbs (4kg) after a maximal expiration (there is always some residual volume of air in the lungs). The buoyancy of the human body also goes from neutral to negative after expiration.

The question is, do we hold the air in our lungs for as long as possible after putting our face back in the water, then exhaling with a quick burst prior to capturing the next breath? Or, do we do as the Red Cross teachers told us to do as children, trickle the air out of our nose or mouth, prior to the next breath?

The changes in body weight and buoyancy can impact frontal drag of a swimmer, particularly while swimming on the surface. The higher the swimmer can be on the surface, the less frontal drag and the faster the swimmer can go. A swimmer is faster in salt water, where there is more buoyancy, than in fresh water. The density of water is so great that just a few millimeters of difference in body position on the surface can have a significant impact on a swimmer’s speed. So, it would seem logical that swimmers would want to keep the air in the lungs as long as possible, weigh less, be more buoyant and burst the air out of their lungs at the last moment, before turning the head for the breath.

What Do the Best Do?

But that is not what great swimmers do. Katie Ledecky, Sun Yang, Grant Hackett, Ian Thorpe, Michael Phelps and virtually all of the other great freestylers release some air through the nose immediately upon planting their faces back in the water after the breath. The great butterflyers of the world do the same. With the speed of their bodies moving forward, those air bubbles from the nose move underneath their bodies before finding their way to the surface. The rest of the exhalation comes just before and while the head is turning or elevating for the next breath. In that manner, the inhalation can begin immediately once the mouth reaches air, so the head can return promptly to the face down position without slowing the stroke rate.

Air Lubrication System

I did not recognize the significance of those bubbles until one of my swimming colleagues at the pool in Islamorada, Florida brought the Emperor Penguins to my attention. The Emperor Penguins of the Antarctic Ocean have evolved to develop an air lubrication system in order to escape the wrath of the hungry seals chasing them or launch themselves out of the water. Under the plumes of their feathers, they manage to trap air bubbles. When the seals are chasing the penguins for lunch, the penguins release the air from under the feathers and gain a significant amount of speed, presumably while kicking with the same amount of force with their webbed feet and wings. By releasing the air bubbles, surrounding themselves with air instead of water, they effectively lower their frontal drag forces, which enables them to spurt forward out of harm’s way.

Think of those air bubbles under your chest as if they were marbles on concrete. It is much easier to move over the concrete with marbles. The same is true with air bubbles in water. Cruise ships and shipping companies have recently developed an air lubrication system to release air bubbles underneath the hull in order to reduce a ship’s frictional drag.

The Art of Breathing

Could it be that the air bubbles under the swimmer’s body released after the breath do the same as an air lubrication system to a lesser degree? Perhaps. What I do know is that great swimmers usually do the right thing, whether they understand the reason for doing so or not. Releasing some air through the nose after the breath may just be another example of that. So that is what I do and recommend others do.

In the upcoming third and final article of this series, we will examine the most controversial breathing topic of all and that is how often to breathe.

Yours in swimming,

Gary Sr.

Read: How Oxygen Affects Our Bodies in a Swim Race: The Art of Breathing Part I

Read: Oxygen! How Often Should I Breathe in Swimming?: The Art of Breathing Part III

The Race Club Aqua Notes Air Lubrication System

7 Responses to How to Breathe While Swimming: Air Lubrication System

  1. Glen Osborne

    That was a fascinating arrival about air lubrication.
    I exhale from my mouth mostly and
    thought it best to keep lungs empty
    To be ready to immediately inhale.
    The thought is that oxygen is fuel.
    It’s also good to learn more about
    drag, as at 53, I have accumulated
    some mass.

  2. Publiclapswim

    Thanks for your work on these topics. Please touch on the play between surface drag and underwater drag (and is a third type of drag where these two meet?). Specifically, is it best to stay high on the surface or keep your head down and work underwater. In “How to Breathe While Swimming: Air Lubrication System” you say: “The higher the swimmer can be on the surface, the less frontal drag and the faster the swimmer can go.” Yet “10 Ways to Reduce Frontal Drag” reads: “There is actually less drag underwater than on the surface of the water (think of a submarine), because we eliminate surface drag.”

    • garyhallsr

      This is a confusing area, as it seems as if we are contradicting ourselves. The fastest way to swim is by hydroplaning…ie swimming above the water. It is estimated that we will need to be swimming at around 15 mph in order to achieve this. WR speed in the 50 is just over 5 mph, so that won’t be happening any time soon. The second fastest place to be is underwater. However, since by rule, we must swim on the surface, the higher we are on the surface (more air, less water), the less frontal drag. We can sustain a ‘high’ position on the water for only a brief time (50 meters) because the amount of force (down kick and early pull) required to lift the human body is significant. Hope this helps to clarify.

  3. jon selby

    Dear Gary sr,

    Please comment on what you said here: ” In freestyle, that means turning the head minimally (keeping one goggle lens in the water during the breath), elevating the mouth to one side to meet the air, and rotating the head posteriorly (backward) rather than straight to the side or forward.”

    I do not understand the part about “rotating the head posteriorly”. I understand that the ideal situation is as little movement from the body line as possible during the breath – so turn the head sideways, one goggle in , yes. But rotating the head ‘backward’? That would mean a deviation from the body line and in my experience causes a snaking movement in the swimmer.

    • garyhallsr

      When the head lifts (breaks the surface) for the breath, it creates a wave. The crest of the wave is more or less straight to the side, but the trough of the wave is in front of that (moving backwards)…or more posterior relative to the body. By breathing in the trough, one needs to turn the head less. We do not need to deviate the head from the line of motion in order to do that. We simply need to rotate with our chins closer to our chest. This makes the breath faster, easier, safer (less chance of swallowing water) and causes less frontal drag (ie better).

  4. jeff silvernale

    I second the comment from publiclapswim.
    I read from your earlier blog that resistance was less below water so I’ve been trying to tuck my head down as much as possible. I also thought I read the drag at the interface between water and air is the worst, but obviously there isn’t much to do about that except on the turn (i.e. stay below as long as possible). Now I read drag is less above water so I need a breakdown from you if you don’t mind.

    • garyhallsr

      Watch the video of Zane Grothe from Indiana swim American record 1650 freestyle (Swim Swam). His head goes under water after the breath on each freestyle stroke. By doing so, he reduces frontal drag by around 20% over keeping head above water.


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