With commentary from running luminaries like Bill Rodgers, Frank Shorter and Grete Waitz and stirring footage from such far-flung locales as Japan, Kenya and Greece, director John Dunham's ambitious "Spirit of the Marathon" is perhaps the most comprehensive accounting of the history and experience of marathon running ever packed into 104 on-screen minutes.

But it's the half-dozen principal subjects of the film — two elite runners and four almost-everyday athletes in various stages of progress — that ground the expertly executed documentary in the sort of individual human drama at the heart of every 26.2-mile race — the sort of drama that has made the film a critical and (in limited release) popular success since its release last year.

"It was always our aim to make a film that could appeal to everybody," Dunham said. "We never wanted to 'a runner's film.' We wanted to explore this event and how it exemplifies personal achievement and triumph. That's something everyone can relate to."

Dunham, who ran his first marathon in 1993, culled from a list of nearly 80 possible candidates before arriving at American Olympic marathoner Deena Kastor, Kenyan-born elite Daniel Njenga Muturi, Boston Marathon aspirant Ryan Bradley, senior runner Jerry Meyers, and first timers Leah Caille and Lori O'Connor, a Northwestern graduate student.

Chosen for the diversity of their backgrounds, experiences and running abilities, the six allowed Dunham and his crew to chronicle their individual journeys to (hopefully) the finish line of the 2005 Chicago Marathon.

Interwoven into the storylines are insights and commentary by an impressive roster of venerable runners and running authors, including Alberto Salazar, Paula Radcliffe, Hal Higdon, Joe Henderson, Amby Burfoot and many others. The individual stories also serve as launching points for brief but compelling explorations of marathon history and the cultivation of the marathon mystique.

For example, Muturi's story — which includes his upbringing in Kenya and his eventual recruitment by a Japanese racing team — includes a retrospective on the history of African runners dating back to Ethiopian hero Abebe Bikila, as well as a sobering look into the dangers faced by contemporary African runners in their own countries.

In one of the film's most entertaining moments, Bradley, who was seeking to qualify for Boston after missing out by just 22 seconds the year before, demonstrates the performative gulf that exists between elite and recreational runners by attempting to run at an elite per-mile pace on his treadmill. The treadmill, alas, can't go that fast and Bradley struggles to maintain for even a few seconds a pace slightly slower than runners like Kastor sustain for 26.2 miles.

Still, the marathon experience is as much about shared experience as it is about hierarchy. Both Bradley and Kastor suffer significant injuries during their training. Ultimately, only one would make it to the starting line in Chicago.