Not only is it vital to learn proper breathing during the freestyle, but experts say you also need to breathe properly on alternate sides. This bilateral breathing -- inhaling and exhaling, in turn, on both your right and left sides -- is most swimmers' preferred breathing method. The main reason: symmetry.
Breathing on just one side can make your stroke lopsided, so that you don't swim in a straight line. The repetitiveness can also mess with your body rotation in the water and cause shoulder pain and injury. But breathing bilaterally doesn't necessarily mean switching sides every time you come up for air. It can mean swimming an entire lap while breathing strictly on one side, then breathing on the other on the next lap. The key is that balance.
Kevin Koskella, the author of "The Complete Guide to Triathlon Swimming," switched to bilateral breathing after a massage therapist noticed how much more defined the lateral (back) muscles on his left side were than the ones on the right. "Putting two and two together," he wrote in an article for Active.com, "I realized that years of right side only breathing in the pool had caused me to use the muscles on my left side far more than my right." When, as Koskella points out, you roll to your breathing side as much as a thousand times during an hour-long swim, you develop muscle strength on just that side. To develop and maintain strong lateral muscles on both sides, you need a breathing technique that works the right and left sides equally.
In the next section, we've given you some tips for the best bilateral breathing technique.