Surprising new research suggests fish could be the greatest athletes on Earth.

A team of scientists discovered fish are much more effective at delivering oxygen throughout their bodies than any other animal, giving them a significant "athletic edge," the ARC Centre of Excellence in Coral Reef Studies.

"Fish exploit a mechanism that is up to 50-times more effective in releasing oxygen to their tissues than that found in humans," said study lead author, Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies at James Cook University. "This is because their [hemoglobin], the protein in blood that transports oxygen, is more sensitive to changes in pH than ours and more than the [hemoglobins] in other animals."

This impressive talent is especially helpful in times of stress, when the fish is utilizing its athletic abilities to escape a hungry predator. In these situations, fish can double or even triple oxygen delivery to their tissue. To make their findings, the researchers monitoring muscle oxygen levels in real-time in rainbow trout.

"This information tells us how fish have adapted this very important process of getting oxygen and delivering it to where it needs to be so that they can live in all kinds of conditions, warm or cold water, and water with high or low oxygen levels," Rummer said

"This trait may be particularly central to performance in athletic species, such as long distance swimming salmon or fast swimming tuna," added co-author, Colin Brauner from the University of British Columbia. "For fish, enhanced oxygen delivery may be one of the most important adaptations of their 400 million year evolutionary history."

The findings were published in a recent edition of the journal PLOS ONE.