A runner plans to participate in one marathon per day for 50 consecutive days.

Dean Karnazes says he's not crazy for committing to run a total of 1,310 miles in less than two months.

The 43-year-old is one of the world's best ultramarathoners. He once ran 350 miles without stopping. He also ran a marathon to the South Pole, and ran across the California desert during the summer.

For his next challenge, Karnazes says he will test the limits of the human body.

He says to Reuters, "I'm curious to see what the limits of human endurance are... I still haven't found them."

For each 26.2 mile race, Karnazes and his family will travel to a different state.

He trains by running 80 to 175 miles per week in the San Francisco area where he lives.

In the last five months, he has run an average of two marathons per month, as well as some ultramarathons, which are longer than 26.2 miles.

Karnazes says, "It's almost like designing an engine that can go 200 miles an hour for a 100-mile-an-hour race."