It's very unlikely that you will hear someone say "that guy is so plump! I bet he's a great swimmer." However, according to researchers from the NOAA, that's exactly what we should be saying for sea turtles.

A study recently published in the journal PLOS One details how NOAA experts teamed up with researchers at the University of Wisconsin-Madison and Florida Atlantic University to determine what makes a swimming animal the most "fit."

By measuring the forces that act against a swimmer and the energy required to move through the water, researchers found that slender and seemingly hydrodynamic sea turtles are actually worse off than their fatter compatriots. That's because more rotund turtles are somehow getting more out of each stroke of the flipper, and naturally have more strokes in them.

The team determined this after constructing several computer models based on their real-world data to run various swim condition scenarios.

"Swimming animals are very, very difficult to measure experimentally," study lead Warren Porter said in a statement. "It's very difficult to get drag and thrust."

Because of this, Porter and his colleagues initially thought the result that portly sea turtles were the apex swimmers or their kind must be a mistake. However, after a closer look at the data and scenarios, the researchers found that the flippers of thinner turtles come closer together at the bottom of their stroke than those of larger turtles, causing them to lose power.

Porter now hopes to take this valuable lesson about swimming efficiency and apply it to a larger scale.

"Now that we have [models] for both marine and terrestrial environments, we can ... get back to the big mass extinctions and get some insights into how did animals live before and after those extinctions," he explained. "Why were the animals that survived able to survive?"