Sgt. Kristy Rodriguez is sprinting on a treadmill. She's wearing dark green shorts, a matching T-shirt and white sneakers. The pace keeps getting faster.
Rodriguez is at Camp Lejeune in North Carolina, taking part in a Marine Corps experiment to determine whether women will be allowed to serve in ground combat units.
"A lot of people think that we can't do it," she says. "I don't think the same."
As she runs, Rodriguez stares at a photo — the iconic shot of Marines planting the American flag at Iwo Jima.