Black Girls RUN! at 2013 Broad Street Run

A little more than three hours after the first runners left the starting line this morning, I slowly started making my way to the exits of the Navy Yard.

As I went to enter the parking lot, two runners in red caught my eye. They'd been running for three hours, yet these women were running as hard as anyone I'd seen all morning.

After they crossed the finish line—arms raised above their heads in triumph—I caught up with them, curious what would motivate two runners to continue racing long after the top competitors had crossed the finish line and the outcome was decided.

That was how I met Juana Minney and Shani Fields of Sicklerville, NJ. Both women represent Black Girls RUN! , a group determined to encourage African-American women to make fitness and healthy living a priority.

"See, historically black girls don't run," said Fields, a fun-loving competitor who ran wearing a bandana reading "WTF? (Where's The Finish?)"

"That's why [African-American women] have high rates of obesity, cardiac disease and diabetes."

Wait a minute, I tell her. Two hours ago, I saw the male and female winners come through this same tunnel—and both were black.

"Oh, we have some exceptional black runners," admitted Fields. "But for all those women you saw finishing this race in under an hour, there are so many more who don't run at all."

Indeed, the Centers for Disease Control place the rate of overweight African-American women at a staggering 80 percent.

Both Fields and Minney are mothers, and say they run to lead by example—for their own children and the next generation of African-American women. "We have to lead by example," said Fields. "I take my children with me running now—if I can do it, there's no excuse for them not to participate."

"Your race, your pace," said Minney. "We have a pace, and we stay at that pace. And we finish."

Michelle Getchell, another member of Black Girls Run!, had the honor of awarding Fields and Minney their medals ('I'm on the injured reserve right now,' she lamented.) "I'm just ecstatic to be here at the finish line and award them these medals," Getchell added.

The two women credited one another for their ability to run the race at all. "It's important to have a pace partner," said Fields. "No woman left behind. I never would have imagined running Broad Street."

And when you have that level of commitment, they added, who cares about finishing time? "See this medal?" asked Fields. "Same one as those people who finished in 50 minutes."

So there's the answer. That's why even after three hours, 8 minutes there were people on the course this morning. The crowds may have been thinner, the cheers quieter—but the message was stronger than ever.

Read more Sports Doc for Sports Medicine and Fitness.