The answer is going to turn on how the term "marathon runner" is defined. NOVA's framing of the answer is one of the two things that'll make actual marathon runners dislike this documentary. This will be addressed below, but for now consider the other likely sore point for runners: these couch potatoes aren't going to run just any marathon; they're running the Boston Marathon. As most every runner knows, this is the preeminent marathon. To enter the Boston Marathon, most runners must post a qualifying time at another marathon. For a 44-year-old male the qualifying time is under 3 hours 21 minutes. None of NOVA's couch potatoes are going to come even close to this. They will be participating under the exception made for the five percent of entrants who buy their way in with a large charitable donation. The documentary, unfortunately, doesn't even mention this, much less identify the charity being helped.

The thirteen couch potatoes NOVA enlists provide a good cross sample of the sedentary population of Boston. Many are obese. Many have body fat compositions more than twice the recommended level. Some are able to utilize oxygen at only one-quarter the efficiency of serious runners. Some have diabetes. Several are older. One is HIV+ and another has suffered a heart attack.

NOVA is of two minds as to what this documentary should be. In part, it's going for reality TV. As one participant put it aptly: "I do feel like I'm on some new sort of latter-day public television version of Survivor." Toward this end, much of the brief 56-minute runtime is devoted to the drama, especially tearful frustration and self-pity among the women and doubt about who will make it through the challenge. Ho hum.

Even if Marathon Challenge were focused exclusively on the drama, 56 minutes is not very much time to tell the story of 13 people, never mind that the group loses and gains members as the story moves along. However, the drama is only part of the story. The other half is the science behind the scenes. Some of the questions addressed include how inefficient are the bodies of sedentary people in comparison to marathon runners, what is a healthy baseline and how can ordinary people achieve it, and what benefits does training for a marathon bestow beyond those achieved by more modest routine exercise.

The encouraging news is that dramatic gains can be made in oxygen utilization and overall health in a short period of time through routine moderate exercise. By week nine, even though the participants hadn't yet completed a 5-mile run, the efficiency of their hearts had improved, their veins were more elastic, their muscles had increased capillaries, and the number and size of mitochondria in their cells had increased allowing for faster transformation of fat, carbs, and oxygen into energy. By month five, despite just working up to 10-mile jogs, ninety percent of the gains in oxygen efficiency had been reached. From this point forward, most improvements would be limited to muscle capacity and mental stamina. This is great news for couch potatoes, and the inspiring take away from this documentary. It's not necessary to be able to run a marathon to experience dramatic improvements in fitness; routine exercise is all one needs.

The bad news though is that running doesn't consume as many calories as one might think. Unfortunately, running a marathon may consume only twice the number of calories the body normally needs in a day. Of the participants, only one experienced much loss of weight or body fat and she accomplished this through a dramatic change in diet. Diet, not exercise, is the key to weight control we're told.

Finally, despite a mild bit of drama along the way, the group "runs" the Boston Marathon. The best quarter of the bunch turn in times that aren't too shabby for older first-time marathoners. However, much of the group posts times slower than most mall walkers stroll. To hold these participants up as marathon runners will no doubt irritate actual marathon runners, especially those who have earned their way to the Boston Marathon the old fashioned way.

The DVD

The Video:
Marathon Challenge appears to have been shot on above average digital video. It is presented in 1.78:1 letterbox. There is no standard subtitle options, though the disc apparently includes closed captioning that can be utilized through some television menus, though these weren't compatible with my home theater projector.

The Audio:
The disc provides an adequate 2.0 stereo mix, and offers an optional enhanced audio description for the blind.

The Extras:
The disc includes a PDF file of classroom materials and trailers for other WGBH Boston releases.

Final Thoughts:
Actual runners are going to hate Marathon Challenge for denigrating so completely the idea of what it means to be a marathon runner, but couch potatoes looking for a little assurance that anybody can complete a marathon may like this. There's a bit of mild Survivor-lite drama, and more importantly some encouraging news on the benefits of routine exercise. If you're looking for some encouragement to put on your sneakers and get out there, Marathon Challenge may be worth renting.