AUBURN – The six-day marathon a few years ago was, in a word, awful.

Mike Brooks’ feet swelled two sizes. He was exhausted, in pain. He waved at planes leaving LaGuardia and JFK and named the ducks in the Flushing Meadow Park to pass the time. By the end, he was too tired to drive himself home.

No, Brooks is not doing that six-day marathon again.

He’s doing the 10-day.

On Wednesday, the 63-year-old Danville man will be the second oldest runner in the Sri Chinmoy Self-Transcendence 10-day marathon in New York. He’s hoping to run 500 miles and raise $10,000 for Camp Sunshine.

He’ll give himself four to five one-hour-long sleep breaks a day.

“I guess it’s on my bucket list,” Brooks said days before the race. “It’s probably the most extreme thing I’ll ever do.”

In 2006 he ran 320 miles in the same park, a one-mile loop at a time.

“That was a miserable six days. I went into that with an injury. That’s why I skipped for a few years. I had to try to get it out of my mind,” he said.

This time, he’s injury-free and feeling good. He ran his last marathon, No. 245, in Washington State two weeks ago and has let himself take it easy since. There’s really nothing to eat to prepare for a 10-day race, Brooks said. He is, though, getting ready for Sri Chinmoy’s no meat menu.

“The first thing I’ll do is a cheeseburger and bottle of beer (to celebrate),” Brooks said.

The race starts Wednesday and runs through May 2.

Brooks, a retired firefighter, started marathoning in the early 1990s. He’s dedicated several distance races to Camp Sunshine, a Casco camp for sick children and their families. The camp started a Web site, www.tendaysforsunshine.org, that’ll be updated throughout the race. Brooks said he’s been impressed with the work they do.

“It’s really amazing,” said camp Executive Director Matt Hoidal. “This is a man who’s very determined, very passionate about Camp Sunshine.”

Hoidal said on Friday that $3,000 in donations had already come in, not including a new $1 per lap pledge from the Bronx Lions Club. It costs $1,500 to host one family for a week at the camp.

Brooks said he has noticed he’s gotten slower with age. Used to be he could finish a marathon in under four hours. “Now, if I break five I’m lucky.”

He has some degeneration in his spine, osteoarthritis in knees, and the cartilage is worn out on his big toes. Still, he’s one state away from having run three marathons in every state. Brooks said he loves meeting people and the camaraderie among runners. They like to tease each other.

He calls one runner from Albion “Dad.” (The man is four years older than him.)

“I tell the aid stations, ‘That’s my dad behind me, encourage him a little bit,'” Brooks said. “I bet we’ve run over 30, 40 marathons together.”

After this 10-day race, Brooks said it’s the last you’ll hear from him for a bit. His next big fundraiser for Camp Sunshine, if all goes well: Running an invitation-only ultramarathon through Death Valley, again, at 70 or 71.

“If there’s anything I can do, I’m good at just putting one foot in front of the other,” Brooks said.