Marathons have been run for centuries. But this ancient sport is seeing something new this year with the advent of the World Marathon Majors, a series of races around the world with $1 million in prize money on the line.

The first two legs of the series – the Boston Marathon and the London Marathon – took place earlier this year. Next up is this month’s Berlin Marathon (Sept. 24), followed by the Chicago Marathon (Oct. 22) and the New York Marathon (Nov. 5). The first five finishers in each race earn points. The male and female runners with the most points at the end of the series take home $500,000 each.

The idea, according to Richard Finn, president of the New York Roadrunners Club which organizes the New York Marathon, is to create a grand slam of marathon-running similar to those in the realms of golf and tennis.

“It’s very exciting,” Finn said. “It’s caught on with the athletes and it’s catching on with the media. We think it’s going to catch on with the public soon.”

One of the best things about marathon-running is that anyone can enter and have a pretty good chance of earning a spot in five of the world’s biggest races. The New York Marathon, for example, holds a lottery each year to award spots to runners who apply online.

Runners also earn spots by reaching qualifying times in marathons and half-marathons. Athletes who were invited to run in the previous year’s marathon but pulled out prior to race day also qualify. Finn said 50,000 runners were invited to compete in this year’s race, with the expectation that 35,000 to 37,000 will arrive at the starting line. If you’re a runner and we’ve piqued your interest, it’s too late to enter this year’s race — but there’s always next year. Entries are posted from January to June on the New York Roadrunners’ Web site at www.nyrr.org. For information on all five marathons, visit the World Marathon Majors site at www.worldmarathonmajors.com.

Every marathon runner, from the pros to first-timers, needs to train. Finn said the training process usually starts three to four months before the race. Keep in mind that different training programs are geared toward individual goals. For example, a professional runner aiming for a three-hour time will train differently than a casual racer whose goal is to finish a marathon in five hours.

But there’s one piece of advice Finn has for all marathoners – especially recreational runners.

“Listen to your body when you’re training,” he said. “Most of the injuries that happen in running a marathon happen before you get to the race; they happen during training. People become obsessed with making their numbers during their training program, and they run 10 miles or 25 miles in a day when their body isn’t up to it yet.

“Listen to your body. The idea is to get to the starting line, not to get injured or do your best running during training.”

By definition, marathons are consistently 26.2 miles long — but they’re all different. Finn likens marathons to golf. Each course may have 18 holes, but the design of a recreational course is different from Augusta or Winged Foot and those, in turn, are different from professional courses in England. By comparison, the New York Marathon includes bridges, turns and hills while the Berlin and Chicago courses are flatter, resulting in races based more on pure speed.

“Each marathon course presents its own physical challenges, but the training for the recreational runner — the businessman who’s trying to squeeze in a run in between meetings — is pretty uniform.”