Running a marathon may sound overwhelming, but it could be the key to better health. First-time marathon runners significantly improved their cardiovascular health during training for a 26.2-mile race, according to a recent study.

"This study showed participants had improvements in overall cardiovascular health, but particularly related to the stiffness of theaortic vessel," says Dr. Sara Filmalter, a Mayo Clinic sports medicine specialist. "As we age, the body's vessels become stiffer. But we don't want stiff vessels because that can be detrimental to our health since our body has to work harder to pump blood."

In addition to runners having a substantial decrease in the stiffness of the aortic vessel, which moves blood throughout our body, the study found marathon training improved blood pressure.

The study looked at marathon runners six months prior to training and three week after they completed the race. And on average, the subjects ran about 6 to 13 miles in training per week.

Filmalter says the most interesting finding was that the slowest runners had the greatest improvements in cardiovascular health. So even if running 26.2 miles isn't on your bucket list, you can still benefit from lacing up your sneakers, she says.

"What we can see if that you don't have to run to have the health benefits. Even with a small amount of exercise, there were improvements with overall cardiovascular health and vessel stiffness. So if your knees won't let you run or your back won't let you run, if you just start to walk on a regular basis at a brisk pace, you can reap the health benefits."

Filmalter recommends 30 minutes of moderate intensity activity five days a week. And if you're wondering about the definition of moderate intensity, Filmalter says, "You should be able to talk to whomever you're with, but you should not be able to carry a tune."