The answer is both. While resting, if breathing wasn’t automatic some of us may even forget to breathe. When we were younger we actually used to breathe more efficiently. Diaphragmatic breathing is when you breathe and your stomach and chest expand drawing in more air. As we get older we do more upright breathing, raising our shoulders and chest as our stomach comes in and somewhat buckles. Upright breathing doesn’t allow us to take a full breath in, and therefore turns us into shallow breathers. Most of us primarily conform to this style of breathing because we care what society thinks of us. Some of us subconsciously care more about our self-image rather than breathing with efficiency. Upright breathing isn’t detrimental to your health, it’s just more proficient.
When we exercise, breathing is still automatic, but at times we may need to switch it over to manual. Depending on cardiovascular risk factors, while weightlifting we should switch to a mix of a Valsalva and diaphragmatic style of breathing. People with pre-existing cardiovascular complications should not use the Valsalva maneuver during exercise. They should continue to breathe throughout the movement or exhale during the hardest part of the lift so that blood pressure doesn’t become too elevated. Valsalva maneuver is when you take in a full breath and hold it or brace, while pushing against a closed windpipe.
You’ll often hear a coach comment, “Make sure you’re breathing” or “Remember to breathe!” We say this because we either see you’re holding your breath, or we are trying to cue you to control your breathing. The more tired you get the more you hyperventilate. The more you hyperventilate the less oxygen you are able to supply to your bloodstream, the more lactate you begin to build up in working muscles, the less likely you will be able to recycle it out, and the faster fatigue will start to set in. Valsalva breathing is most effective during weight lifting or when needing to keep the body in a tight position. Diaphragmatic breathing should be used between the Valsalva maneuver. Consciously controlling your breathing can allow you to take in more of a full breath. The longer you can control your breathing during workouts and lifts, the longer you are going to be able to recycle lactate, and the longer you will be able to fight off fatigue.
BA Exercise Science, Hope College
MS Exercise Physiology, Eastern Michigan University