When better than Valentine's Day to discuss matters of the heart? As February happens to be American Heart Month, dedicated to heart health and the physical fitness of everyone around the world, it seems that NASA and astronauts aboard the International Space Station are taking the promise of heart health to new heights. A new year, a new crew, and a new attitude has come aboard the International Space Station, and this time they're vowing to keep their hearts just as healthy as their minds and our thirst for knowledge in space exploration.

"Astronauts exercise regularly while in space to maintain muscle, bone, and cardiovascular health and fitness, and to remain fit and strong enough to perform physically demanding tasks such as extravehicular activity" spokesperson from the International Space Station Program Office with the NASA Johnson Space Center Melissa Gaskill says. "[Now] astronauts on the International Space Station are working to keep their hearts healthy too, and at the same time they are generating data to advance knowledge of health and fitness in space and on Earth."

Utilizing a measurement known as "VO2peak" to measure the cardiovascular fitness of astronauts before, during and after missions of four to five months, researchers with NASA's Exercise Physiology Laboratory are finding out just how healthy astronauts hearts are by measuring the peak oxygen uptake of their bodies. VO2peak is measured by researchers using a bicycle test, wherein subjects are asked to start pedaling at a low level of intensity that gradually increases pedaling resistance until they can no longer pedal the bike.

According to the study recently published in the Journal of Applied Physiology researchers found that while VO2peak levels gradually increased during long-term spaceflight, most astronauts never were able to recover their preflight VO2peak levels during missions. In fact, VO2peak levels on average decreased by 17 percent while astronauts remained in space, but proved to be relatively stable and even improved with a regimen of high intensity exercise.

"Currently, each crew member is prescribed a two-hour daily workout using three pieces of equipment on the station" Gaskill says. "This investigation will help scientists design these individualized exercise programs. The data also will help predict what activities an astronaut should be able to tolerate after a long spaceflight, which will help in planning future missions."

An ongoing study on the International Space Station known as "SPRINT" continues to investigate and evaluate the efficacy of these high intensity workout protocols during long-duration spaceflight. And researchers say that aside from proving the possibility of long-term space exploration, the study has great implications for people down here on Earth too.

"High intensity protocols are very effective in the general population," lead researcher for NASA's Cardiovascular Laboratory, Stuart Lee says. "This form of exercise can benefit not just 20-year olds who want to be fit and strong, but also those in cardiac rehabilitation and pulmonary care."