Breathing on alternating sides, or bilateral breathing, during freestyle can help eliminate cramping, increase oxygen intake, and balance your stroke, explains USA Swimming. Bilateral breathing can also give you an edge during the swimming leg of a triathlon because it helps with sighting, gives you the option of breathing comfortably on either side in rough water conditions and allows you keep an eye on the competition on either side of you.
Three-time Olympian, Gary Hall Sr., explains in his Triathlete article,
“Awkward as it may feel at first, within a few weeks, you’ll become comfortable [breathing on both sides].There are some rough open-water days that you may only be able to breathe safely to one side, so it’s nice to have this option.”
The 1:3 breathing pattern is the easiest to start with because breathing every third stroke forces you to breathe on alternating sides. To execute this pattern, leave your face in the water for the first and second strokes, breathe to one side on the third stroke, followed by two more strokes with your face in the water and a breath to the alternate side on the third stroke.