One-sided or bilateral breathing in swimming?

Many traditional swim coaches have been trained to teach and proliferate the idea that bilateral breathing is the best and only way to swim competitive freestyle. I frequently run into swim coaches that are surprised I would advocate anything else. However, for distance freestyle events (anything over 200 meters), oxygen debt and aerobic/anaerobic issues are important considerations.

In events lasting longer than just a few seconds, a swimmer's ability to maintain maximum speed is related to the predominant energy system being used. Events that last up to about 20 seconds can be primarily anaerobic - occurring in the absence of oxygen (using ATP and CP for energy). That is why you might see a 50 freestyler take only one or two breaths during the event - the oxygen is not necessary for maximum speed at this distance.

However, events lasting longer than a couple of minutes require the aerobic energy system to be used. The aerobic system uses oxygen, carbohydrates (glycogen and current intake) and fat for energy.

For events lasting up to about 5 minutes, the work will be driven somewhat equally by both aerobic and anaerobic pathways - both slow and fast twitch muscle will be operating.

For events lasting longer than 5 minutes, the predominant system is the aerobic system. And here is where breathing patterns become a lot more important. Since I coach primarily triathletes and open water swimmers, we are training for events that last at least 5 minutes and typically more in the 12 to 30 minute duration. Here oxygen intake becomes vastly more important if speed is a concern for the swimmer in any fashion.

Would you tell a race car driver to reduce his fuel consumption by 50%? He would say you are crazy. But that is essentially what coaches do when advocating a bilateral breathing pattern over a one-side breathing pattern to distance swimmers.

There are certainly some streamline and stroke mechanic issues that bilateral breathing can help address, but at some point we need to consider maximum achievable speed via fuel channels versus pure perfect stroke mechanics. This is one of the major points we address in the Powerstroke: Speed through force and form DVD.

In summary, work on bilateral or alternate side breathing in practice and for short pool swimming events, but go ahead and breath as much as you need in open water racing. Just look up every so often to make sure you are swimming a straight line (that's a different article).

Here is a useful article on energy systems from coach Brian Mac of Peak Performance Online.

Coach Marty Gaal, CSCS - March 2010