“If your goal is to finish, you just need to skate enough so that you can cover the distance. If your goal is to be faster, you have to train.”

There are training programs everywhere — in magazines, books, on the Internet. But eventually, exercise physiologists say, most people need guidance from a group with experienced coaches, like the one Mr. Gordon joined, or from personal coaches.

Training, though, can require such a commitment over so many years that many drop out. Not Mr. Gordon, who loves to train. And that love of serious training, coaches say, is often what distinguishes a good athlete from a mediocre one.

“Any great athlete who accomplishes anything, anywhere, loves to train,” said Tom Fleming, my coach and a former elite distance runner who twice won the New York City Marathon.

It’s not that talent is irrelevant. Truly talented athletes can be better without training than many average people can be with training. But most people are not in that elite athlete realm and, for them, training can mean the difference between a good performance and a poor one.

Carl Foster, an exercise physiologist at the University of Wisconsin, La Crosse, gave an example of what training can do. A man who has been running but not training might run a 5K race at a pace of 7:45 a mile. If he trained for six months, he could get his pace down to 6:10.

The biggest effects are in untrained people, said Hirofumi Tanaka, an exercise physiologist at the University of Texas. “Elite athletes’ performance is getting too close to the ceiling or upper limit,” he said. “There is not much space to improve.”

But even people who are starting reach a plateau within six months or so. After that, real gains are incremental and hard won. Yet people regress if they ease up on training.

Personal Best – Proper Training Is a Critical Element to Athletic Success – NYTimes.com.