As CrossFit continues to add more overhead carries into competition athletes must learn how to breathe with their hands over their heads. Holding weight in general compresses the area available to the lungs. In addition, any lack of mobility in the shoulders, ribcage, or diaphragm severely hampers the athlete’s ability to breathe. If an athlete cannot breathe well they literally are no longer creating enough energy and they will fatigue prematurely.
One overlooked factor when coaching these movements is how the position of the ribcage affects the volume of the breath. When you raise your ribcage, which happens when your arms are overhead, you decrease the available movement of your diaphragm. Instead of its usual curved shape, the diaphragm flattens out. This inhibits the athlete’s ability to take full breaths in.
If an athlete lacks any overhead mobility this issue grows exponentially. Now when they place their hands overhead they must arch their back and raise their ribcage even more. This takes their diaphragm out of the equation and they are only able to breathe using their accessory muscles.
To combat this I would recommend two immediate points of attack. First, begin focusing on increasing your range of shoulder flexion. Do this by stretching overhead, but more importantly address any lack of mobility in your external or internal shoulder rotation. If you invest the time needed you will eventually be able to raise your hands over your head without your ribcage flaring.
Secondly, when you press or carry weight overhead begin by exhaling fully. This will pull your ribcage down. Then hold that core tension throughout the movement while you continue to breathe. Holding the ribs down with this tension will allow you to take fuller inhales throughout the workout. Good luck!