SCOTT DETROW, HOST:
We have seen tons of athletes compete at the Winter Olympics over the past two weeks. According to science, athletes in one particular sport rise above the rest by at least one measure. NPR's Jonathan Lambert has more.
JONATHAN LAMBERT, BYLINE: People need oxygen to power their muscle cells. The harder, and especially the longer, they keep pushing their bodies, the more oxygen they need. Stephen Seiler is an exercise physiologist at the University of Agder in Norway.
STEPHEN SEILER: The more oxygen that we're able to extract from the environment, bring into the lungs and then transport to the muscles, the greater our capacity to exercise, to move our body.
LAMBERT: Scientists call this capacity VO2 max. It essentially captures the size of an athlete's engine - how much oxygen they can use when going all out. To measure it, scientists hook athletes up to a mask that tracks oxygen consumption while they're really gunning for it on a treadmill for about 10 minutes. Scientists have looked at all kinds of athletes.
SEILER: At rowers, at cyclists, at distance runners.
LAMBERT: All those sports can produce athletes with big aerobic engines. But when you look at VO2 max across all athletes, Seiler says one sport consistently appears towards the top - cross-country skiers.
SEILER: There's some pretty quite aerobic beasts in that sport.
LAMBERT: Pound for pound, across both men and women, cross-country skiers have some of the highest VO2 maxes ever recorded. Seiler has an idea why that's the case.
SEILER: Cross-country skiing is the only sport that has the combination of that we're standing upright and we're using all four limbs at the same time.
LAMBERT: The heart and lungs have to work really hard to send oxygen to all four limbs and work against gravity. Swimmers, yes, they also use their arms and legs, but they're horizontal, so it's easier for blood to move around. So skiers often end up with the highest VO2 max values.
SEILER: One of the reason, I think, that we see these big values from these athletes is because of the unique physiological conditions.
LAMBERT: Of course, it takes more than a monster engine to be the best skier. Technique determines how much of that raw aerobic power gets translated into forward movement. Ultimately, the best athletes need both. Jonathan Lambert, NPR News.
(SOUNDBITE OF DR. DRE SONG, "THE NEXT EPISODE (FEAT. SNOOP DOGG)") Transcript provided by NPR, Copyright NPR.
NPR transcripts are created on a rush deadline by an NPR contractor. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.