Her legs ached and her body screamed for a break, so Arundel High School cross-country runner Marissa McPhail took it easy on Saturday, enjoying her lightest training day in recent memory.

She ran three-plus miles through the mud. She practically sprinted for the last half-mile to complete her race in a scorching 20 minutes three seconds. She finished ahead -- way ahead -- at the Anne Arundel Invitational, one of the county's toughest, most competitive cross-country meets each year.

"It was pretty easy, kind of a sluggish race for me," McPhail said at the finish line. "I've been having hard workouts, so this was kind of my light day. I didn't have to work too hard."

That's become a common theme for McPhail, a junior so dominant that her greatest challenge is, typically, that nobody challenges her. When McPhail crossed the finish line Saturday, no other runner was in sight. She had time to verify her race time and catch her breath before Leonardtown's Katlyn Dillow came in second -- 22 seconds later.

Annapolis runner Will Eden enjoyed similar dominance. While still recovering from a sore Achilles tendon, he finished the boys' race in 16:27, 29 seconds faster than anybody else.

"It's difficult when nobody is out there pushing you," Arundel Coach Chris Shelby said. "Honestly, I talk about that a lot with Marissa. The toughest thing is running a race by yourself, with nobody there to race you."

Ever since McPhail entered Arundel as a talented freshman, Shelby has made it his responsibility to keep her challenged. In practices, McPhail often runs with the boys' team. "She keeps up with most of us," Arundel runner Greg Marshall said. "She just has a lot of heart and spirit."

When she doesn't run with the boys, she runs against time, not teammates. "She's in a totally different league," said teammate Laura Miffleton. "It must be frustrating sometimes. She always tells me that if she had someone in front of her, she'd run faster. But she never gets that. At practice, the other girls just want to finish within a minute of her."

McPhail grew up in California running with her dad, a former Fresno State runner, and older sister. By the third grade, she was running cross-country race distances. She ran on a competitive team in junior high before moving to Maryland in eighth grade.

By the time she entered Arundel, her form was polished, her mentality mature.

"I had a head start," McPhail said. "In California, running is really big. I just grew up doing this. It's what I always wanted to do. I moved here and realized, 'Wow, maybe I could be good at this.' "

In her freshman year, a top-10 finish in the state championship meet boosted McPhail's confidence. Last year she wound up fourth in the state -- and came home disappointed. "Now we've got our goal," Shelby said. "We're shooting for a state championship, and she's definitely in that class. The key for her is to just keep pushing herself."

It would help, McPhail said, if she could find some competition.

"Right now, practices are usually harder than meets," McPhail said. "There are definitely a lot of great runners around here, but I think I can run with them. I just have to keep running well. My focus is on the state championship."

Right, Arundel junior Marissa McPhail usually has little company on her runs because she is so far out front. Below, Annapolis runner Will Eden, front, has the same problem.