At the marathon that December, 21 of the 25 finished the race, with 15 setting personal bests. Instead of extra miles, participants were encouraged to do two additional days of cross-training. Twenty-five subjects entered, agreeing to run one long run, one tempo run, and one speed workout each week-and no more.

In the summer of 2004, FIRST advertised a free marathon-training program that would last 16 weeks and culminate with the Kiawah Island Marathon. Then they wanted to put it to the test with others. (Murr, for the record, holds a marathon best of 2:46 and has completed multiple Hawaii Ironmans.) “The more we discussed this-and we discussed it a lot-the more we became convinced that a three-day program, with some cross-training, was enough to maintain our running fitness.” “Lo and behold, our 10K, half marathon, and marathon times didn’t suffer at all,” says Pierce, who has run more than 30 marathons and has a best time of 2:44:50. So they cut back to three days of running. To their surprise, they didn’t slow down in local road races.

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