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by Anne Minard

December 14, 2020

High-altitude advantage not as beneficial as once believed

Living in mountain towns, I’ve long believed I could enter races at sea level and enjoy a distinct competitive edge because of my body’s superhero ability to grab oxygen from thin air. This belief was reinforced each time my Masters club’s pools in Flagstaff, Arizona, and now Santa Fe, New Mexico—both more than 7,000 feet above sea level—would host elite swim teams from all over the world for high-altitude training.

But research has revealed that high-altitude training offers little benefit for swimmers and can even slow us down—unless we follow this rule: live high, train high and low.

Not So Fast

Benjamin Levine is a physiologist and professor at Texas Health Presbyterian Dallas and the University of Texas Southwestern Medical who has helped conduct several groundbreaking studies on the subject. Swimmers, he says, have a special problem.

Ultimately it’s a very inefficient sport,” he says. “The great swimmers are the ones that swim with superb economy.”

But swimming at altitude requires an adaptation: more breathing. Called ventilatory acclimatization, the response can persist up to two weeks, making it a bad idea to, say, attend a high-altitude training camp just before a sea-level race.

“If you’re training at altitude and you’re breathing hard, then you go to sea level and you feel like you’re hardly breathing, there’s a powerful psychological advantage to that,” Levine says. “But people observe that they’re going more slowly.”

The problem, he says, is that even at sea level, swimmers are still breathing as often as they needed to at high altitude. And with each extra breath, a swimmer loses efficiency.

Live High, Train High and Low

Levine was a co-author on a research project in 2015 that followed four groups of elite swimmers attending various training camps. The first and second groups lived and trained at altitude, about 7,600 feet above sea level, for three and four weeks, respectively. The third group lived at high altitude for four weeks and trained at both high and low altitude, about 2,000 feet. And the fourth group lived and trained for four weeks between sea level and 2,000 feet. Before their various training camps and immediately after, as well as weekly for four weeks out, all of the swimmers competed in time trials and were monitored for several markers of oxygen transport capacity. The results were published in a 2015 issue of Medicine & Science in Sports & Exercise, a publication of the American College of Sports Medicine.

When they first completed their respective camps, none of the swimmers had improved, and in fact those in the high-altitude-only groups were even a bit slower. But after a week of recovery, all of the swimmers showed improvement over baseline. And two to four weeks out, the swimmers who had lived at high altitude and trained at both high and low altitudes showed more improvement than the others.

The study authors concluded that ‘‘living high, training high and low for four weeks has the potential to improve swimming performance,” stemming from the body’s ability to physiologically adapt to air with decreased oxygen per volume, as occurs at altitude. A person produces more red blood cells, for example. The muscles get better at extracting oxygen.

But Mainly, Train

The study also concluded that no matter where they trained—after they recovered—the swimmers got faster.

A Masters swimmer reaching for the next level need not break the bank for a training camp. Living someplace such as Flagstaff for a month and visiting lower-altitude Sedona, Arizona, for training sessions could do the job.

But for anyone who is in a position to dive into their swimming, training camps work, Levine says, no matter the altitude. The obvious benefits include the singleness of purpose, the coaches, and the nutrition.

“It’s really nice to go into the mountains, a fantastic training setting,” Levine says. “Sometimes it’s necessary to get people away from daily distractions.”


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