The Wow! moment came when Chris McDougall raised his left leg and displayed the bottom of his bare foot. It was smooth, with no calluses or blisters.

The members of the girls' cross-country team at Lower Merion High School were amazed. This was a lunatic, after all, who runs barefoot and had not worn normal shoes, he boasted, since last spring.

Indeed, he had arrived at the school in a pair of Vibram FiveFingers - rubber toe gloves, essentially, with only a thin pad to protect the soles.

"Funny lizard shoes," McDougall called them. "They let your foot move the way it wants to move."

McDougall is the author of Born to Run, which explores the secrets of Mexico's Tarahumara Indians, among the world's most prodigious distance runners.

Wearing only strips of leather on their feet, they can cover hundreds of miles with little rest. More significant, they conquer the most grueling challenges with evident joy.

McDougall, 47, grew up in Drexel Hill and went to St. Joseph's Prep before matriculating at Harvard. In middle age, a succession of chronic injuries halted his running and prompted a quest for relief that led to the book and its most provocative conclusion: Modern running shoes are overengineered and probably do more harm than good. Not only is there no proof they prevent injuries; they might actually cause or aggravate them.

The book spoke to Dermot Anderson, 48, a guidance counselor at Lower Merion and coach of the girls' cross-country team. The school bought 25 copies last summer, which he distributed to his team.

"A lot of stuff in the book resonated, especially the love of running," said Anderson, a former Villanova 5,000-meter ace. "The Tarahumara run to make each other stronger. They run for each other, rather than to beat each other."

"It was very inspirational," said Laura Levine, 18, a senior tricaptain. "When I read that the Tarahumara can go on for days and not wear shoes, it made me realize that as runners we can do more than we think."

In his talk to the team the other day, McDougall called running "the only true sport." The ability to stalk prey over long distances in a unified, cooperative pack enabled early humans to survive and thrive.

Unlike "make-believe sports" such as football, baseball, and ice hockey, which are male-dominated because they depend on upper-body strength, endurance running is a sport in which women can hold their own against men, especially at distances longer than the 26-mile marathon, McDougall said.

Decades ago, women were told not to compete in marathons because they'd damage their reproductive organs, McDougall noted. Today, in ultra contests of 50 miles and more, they leave many male contestants in the dust.

The stereotype of long-distance runners is that they're loners, but McDougall's take-home message was this: "The essence of running is cooperation and collaboration." Runners feed off each other; encouragement is the ultimate endurance fuel.

It was a theme much appreciated by Anderson, whose team, with 40-plus members, is both popular and deep.

"The girls get it - that running is relational," he said. "Their strength is in the power of connection. They run almost harder for each other than themselves."

A team tradition after every meet is to form a circle, hold hands, and salute outstanding performers.

"Even at the Central League championships, after everyone was gone from the park, we were standing in a circle in the pouring rain recognizing each other," Anderson said.

The most entertaining aspect of McDougall's presentation was the invitation to run barefoot. To demonstrate, he summoned Bridget Butler, 17, a senior much beset by injury, to the front of the class for a quick tutorial.

"Think about how kids run," he said. "They land on the balls of their feet, keeping their knees bent and using short, quick, pitter-pat strides."

He instructed Butler to bounce in place like a boxer, to stay light, relaxed, and loose.

"There are only three things you have to remember when you run in bare feet: Keep your landings gentle, keep your feet underneath you, and keep your feet moving fast," McDougall instructed.

A short while later, the entire team gave it a try on the school's synthetic track.

"Lean forward, and let gravity and your quick feet carry you forward," McDougall coached. "Remember, when it comes to your feet, it's not about being tough, it's about being sensitive. When in doubt, relax."

Reactions were mixed.

Eye-opening and liberating, some girls said. Ouch! The track was cold and scratchy, said others.

"I thought it was really cool," said senior tricaptain Carolina Howland, "but to be honest, it kind of hurt."

Afterward, in characteristic fashion, the team gathered around its No. 1 runner, sophomore Lacey Serletti, just turned 16, to sing "Happy Birthday."

Contact staff writer Art Carey

at 610-313-8106 or acarey@phillynews.com.