Deena Kastor was a bronze-medal winner in Athens this summer. Scott Barbour/Getty Images

Those were heady days for U.S. marathoning back in Athens. Here came Deena Kastor, running a brilliantly patient race and picking up the pieces of the field that were strewn across the highway from Marathon to Athens in oppressive heat, to win a bronze medal, weeping as she circled the track to the finish. Couldn't happen to a nicer, more deserving woman.

On the final night of the Games, just hours before the closing ceremonies, there was Meb Keflezighi running with the chase pack for most of the race before breaking free in the final 10K and taking the silver medal. Never mind that frontrunner Vanderlei Lima was shoved off the course by a spectator (a "defrocked Irish priest'' with a political agenda). The leader was fading fast and did very well to hang on to his bronze medal. Keflezighi was strong at the finish. Couldn't happen to a nicer, more deserving man.

On Nov. 7, both Kastor and Keflezighi will run in the New York City Marathon, the second most famous marathon in the United States (after Boston) and the world (after Boston). What is left of their prime fitness after peaking for the Olympic Games and running bravely in crushing conditions (Kastor's worse than Meb's) is anybody's guess. Few runners can deliver great marathons 10 weeks apart.

Yet, in many ways, their appearance in New York is a victory tour of sorts, much like Michael Phelps' lucrative swimming tour. Come see Deena. Come see Meb. Their performance could be called an afterthought. Yet in the Athens afterglow, Kastor and Keflezighi represent the New Generation of American marathoners. They are more than just names on the starting line on the Verazzano Bridge; they are the first U.S. male and female ever to win medals in the same Olympic Games. (And the first of any kind since Joan Benoit's gold in Los Angeles in 1984). Theirs was no small breakthrough.

But was it really a breakthrough? Somewhere on list of great American sports trends of the last 20 years is the collapse of competitive U.S. marathoning. It's down below the longball-and-steroids arc of Major League Baseball, the flood of high school athletes to the NBA and the rise and fall of Tiger Woods. But if you look, it's there. And you don't have to squint. No U.S. male has won New York since the great Alberto Salazar in 1982 or Boston since Greg Meyer in 1983. No American woman has won New York since naturalized, 42-year-old former Brit Priscilla Welch in 1987, or Boston since Lisa Weidenbach in 1985.

Distance running has changed as much as any sport on the planet in the intervening years. Africans had shown themselves capable of great things (see: Kip Keino, as far back as 1968) before the early 1980s, but their national federations had lacked the money to successfully organize the vast well of talent. With the influx of shoe company money, European agents and, cynics have suggested, first-rate performance-enhancing drugs, Africa has dominated international distance running since the late 1970s. There is little to suggest that it will stop anytime soon. Americans, meanwhile, ran slower as an elite populace for nearly every year post-Salazar into the turn of the century. Here we pause: When measuring U.S. marathon performances, I don't include Khalid Khannouchi, the former world-record holder who came to America in 1992 at the age of 21. Khannouchi came through the Moroccan training system. He is a U.S. citizen, but a Moroccan runner. What about Keflezighi? Similar, but not exactly the same. Keep reading.

This year's New York Marathon field is not overwhelmingly strong. Keflezighi could do very well, as could Kastor. (It should be noted that while Kastor could have won last weekend's Chicago Marathon -- the winning time was 2:23:45, slower than Deena's PR -- Keflezighi could not have beaten Kenyan Evans Rutto's 2:06:16. Khannouchi was fifth in the race). The Athens hangover factor will loom large, but let's say one or both of the Americans wins... or contends. This also has not happened in many years.

What does it mean to the overall U.S. marathoning picture? I would argue that it means nothing. It's one small spike on an EKG line. In recent years, a number of reasonably well-funded training enclaves have spring up to buttress the training efforts of would-be U.S. marathoners, yet with little tangible results. It could be argued that both Kastor and Keflezighi earned their medals because of training and racing opportunities made possible by their involvement with Team USA California, out of Mammoth Lakes, Calif.

Yet this group has not produced a wave of great marathoners, just two. It's a chicken-egg argument. Kastor and Keflezighi are both unique individuals who would have thrived in any supportive setting. Kastor is a tough, dedicated runner who has been building base and speed since she decided against opening a bagel shop and continued her running career a decade ago. Keflezighi is Eritrean, having emigrated from that civil warn-torn nation with his 10 siblings when he was 11 years old. (This is the difference between Meb and Khannouchi; Keflezighi learned to run in the United States).

I would argue that the system did not produce Kastor and Keflezighi; it simply gave them the chance to find their talents. Maybe that's what a system is made to do, but the Ethiopian system seems to do something more.

The great U.S. marathoners have always been deeply individual. Salazar, Shorter, Benoit. None of them came from a cookie cutter, none from a mold. None of them were produced by a system. It is the fate of U.S. marathoning: Sit back and wait for lightning to strike. It happened in Athens, and Kastor and Meb are riding the wave. Enjoy it, honor them and do not hold your breath, waiting for the next generation to follow.

Sports Illustrated senior writer Tim Layden weighs in with a Viewpoint every Friday on SI.com.