Respiración nasal durante la natación
Breathing through the nose while swimming is certainly possible, however it's not recommended.
In most swimmers, breathing through the nose does not supply enough oxygen to fuel your body during a swim. Additionally, it can be very difficult to even take in any air through your nose when you're breathing during any of the 4 strokes, as there is generally not enough time either. The whole point of the breath in swimming is to be quick and efficient. Breathing through your nose is neither. You're able to take in much more oxygen through your mouth.
Exhaling through the nose, however, is highly recommended. While your face is submerged, it's important to let out your oxygen so that when you turn your head to take a breath, you can focus solely on the inhale. If you turn your head and need to exhale and inhale, you'll find that you often do not have enough time, and doing both at once will fatigue you much quicker.
With that being said, taking deep, steady breaths through the nose at rest during or after intense sessions of swimming can help aid in muscle recovery and reduce the effects of exertion.