Where's the best spot to jog in Cambridge?

John J. O'Neil says Fresh Pond is "the best place ever." and he should know. O'Neil, a 69-year-old retired postman and lifelong Cambridge resident, used to trot around Fresh Pond three times a day until he suffered a heart attack several years ago. Now he walks around the pond once a day, sometimes twice "if I feel good."

Other local runners and athletic equipment salesmen mention the banks of the Charles River and the path around Mystic Lake as some of the most popular jogging courses, but it's hard to argue with O'Neil's logic.

"It's beautiful here, and there's no one who will bother you," he says.

Fresh Pond, which is about a ten minute run away from Harvard Square via Concord Avenue, serves as a water reservoir for all Cantabridgians, and a semisecluded track for the city's jogging population.

Thomas W. Danehy, former mayor of Cambridge and currently a city councilor, started running around Fresh Pond when he was 17. Now he jogs there at least six times a week and says. "If you're not at the pond before 8 a.m., you almost need a traffic cop to get by."

Danehy adds that the track is so popular that "you can get there at four in the morning and you're still not the first person there."

Zack Boukydis, a Harvard medical student who plans to run in the Boston Marathon "eventually," says he prefers the Fresh Pond track over the Charles bank where automobile fumes can often pose a problem.

And Karen Bray, a 29-year-old North Cambridge resident, agrees that Fresh Pond is superior to the Charles for running, although the Charles River toepaths provide courses varying from one mile to 17 miles for the entire circuit.

"Fresh Pond is great except you shouldn't run there alone at night if you're a woman." Carla Desbois, of Brine's Sporting Goods in Harvard Square, says, and salesmen at other area athletic equipment stores agree.

Every Saturday morning at 10:00 a.m., a group of local runners hold two informal, but competitive, races that are open to the public around Fresh Pond--one 2.5 miles long, the other five. During the summer weekly races at Fresh Pond are sponsored by the Cambridge Sports Union.

"This certainly isn't Cocoa Beach, where you feel the sand between your toes," Ray Morth, a 51-year-old daily Fresh Pond jogger says, huffing heavily between words. "But," he adds, "it's the closest thing we've got."