The Effects of Deep Breathing Before a Race: Does it Help or Hurt?

Photo Courtesy: Ann Wigger

By McKenna Ehrmantraut, Swimming World College Intern. 

Breathe in – one, two, three. Breathe out – one, two, three.


Photo Courtesy: Trever Gray

Deep breathing is an extremely common practice before a race within the swimming community, but few have an explanation for why it may be beneficial. Why is that we choose to change our breathing minutes before competing? Trever Gray may have the answer.

Gray, a life-long swimmer, has a Master of Science in Integrative Human Physiology and earned a Bachelor of Science in Exercise Science and Nutrition. While in a cardiopulmonary physiology class, he began thinking about swimmers doing deep breathing behind the blocks to calm their nerves. He wondered if deep breathing was truly beneficial to performance. This thought launched him into a study on deep breathing and its effect on swimmers.

The Study

Along with copious amounts of background research, Gray conducted a study on the effects of deep breathing on performance in a group of seven college swimmers. Data was collected over three days, with two races per day. The swimmers were asked to follow their normal pre-competition routine the days leading up to participating in the study and to continue throughout the three days.

When they arrived at the pool, Gray had them fill out forms that included some basic information. The swimmers then hopped into the pool for a quick warm up consisting of one 300, 12x25s and a few dives.

The swimmers then randomly chose a piece of paper out of a bag. There were six pieces of paper in total, with one of the following printed: a sprint 50 with no deep breathing, a 50 with 30 seconds of deep breathing, one 50 with two minutes of deep breathing, and each of these conditions repeated with the distance changed to 100s.

After picking which race the swimmer would be completing (eventually, each swimmer would do all six races), they would rest for five minutes and then start their breathing exercise (if protocol dictated deep-breathing). Once they completed their deep-breathing, they would wait for thirty seconds before starting their race.


Photo Courtesy: Travis Bender

Gray recorded the races on a camera from different angles in order to get an accurate time reading. Immediately after the swimmer completed the race, he pricked their finger to gather a blood sample.

“The literature shows that deep-breathing ‘jump starts’ the anaerobic system. If this is so, then we should see higher levels of lactate [in the blood] post swim compared to no deep-breathing,” Gray explains. And that’s exactly what he saw – higher lactate levels, which confirmed that anaerobic processes were elevated.

After the swimmers’ blood has been taken, they completed a 300 cool down, rested for thirty minutes (to better resemble a normal meet routine), and then repeat the whole process with a new distance/breathing pattern condition.

The Results

After calculating the results, Gray determined that 30 seconds of deep breathing would decrease the swimmer’s time by roughly .27 seconds in a race that concludes in less than 50 seconds. Contrary to his original hypothesis, he saw that two minutes of deep breathing actually led to a negative impact on the swimmer’s time.


Photo Courtesy: Google Images

The results of Gray’s study showed that two minutes of deep-breathing worsened the swimmers’ performance. “It lowers your blood pressure, and when you start exercising, your blood pressure goes up. If you have a drop in blood pressure, it can reduce performance. The blood vessels dilate, which allows more oxygen into the muscle cells and allows more carbon dioxide into the blood stream. The opposite happens when you have been deep breathing for two minutes.”

Sprinting vs. Endurance Races

This test was conducted on a variety of swimmers, both distance and sprinters. Gray found that while sprinters were seeing improvement in their times with thirty seconds of deep breathing, distance swimmers seemed to have an increase in time. “Distance swimmers usually have better developed aerobic systems. Since deep breathing jump-starts the anaerobic system, and distance swimmers have ‘smaller anaerobic engines,’ the effect could be minimized in the distance swimming population.”


Photo Courtesy: Sarah Ehrmantraut

When asked what Gray would change about his study if he had the opportunity, he said he would test blood pressure and oxygen saturation in addition to testing the swimmers’ blood. He would also add a one-minute deep breathing condition as well as a thirty-seconds off and thirty-seconds on condition into the mix of breathing exercises due to the improvement observed when he preformed those breathing exercises on himself.

The Benefits of Deep Breathing

In conclusion, Gray found that sprinters would drop roughly .27 seconds if they did deep-breathing for thirty seconds prior to their 50s or 100s, as long as their times are under fifty seconds: “Deep-breathing should enhance sprint performance in anaerobically developed swimmers giving them a competitive advantage.”

It will be fascinating to see what future research finds regarding the effects of deep breathing. Have you tried this practice before a race?

Contact Information

Gray is submitting his study to the Journal of Swimming Research. If you’d like to contact him with further questions, use the options below:


Follow on Instagram: @trevergray


  1. avatar

    common sense.

  2. avatar

    Good info for alot of swimmers

  3. avatar

    Very neat! Didn’t consider this before!

  4. Hearing Doc

    Really interesting article. Thanks Swimming World

  5. Jane Hoy DeGiacomo

    So…slow swimmers benefitted by deep breathing. And fast swimmers won the races. Gills. Gills are good.