Over the course of a generation, the marathon has undergone a startling change in status. What was once a loopy stunt attempted by only a few weirdos is now a rite of passage for many men, the coolest test out there of fitness and health.

My buddy McDade actually put running a marathon on his list of "Things a Man Must Do in His Lifetime," right there alongside reading War and Peace and seeing the Grateful Dead. (This was before Jerry Garcia croaked.) McDade is hardly alone. Last year, nearly 400,000 runners finished marathons in the United States, up from 300,000 in 2000 and a mere 25,000 in 1976.

On one level, you can file our current marathon mania under "extremely good news," since there's little doubt that training for the race is one of the best ways to improve your health and fitness. Over the years, studies have shown that regular exercise decreases everything from high LDL cholesterol to high blood pressure.