It’s a given that runners—no matter their ability or age–have to be tough. Let’s face it: this beloved sport of ours is a demanding one that requires Herculean levels of determination and just pure grit in order to keep on putting one foot in front of the other.

And so when it comes to competing at the highest levels of running, it’s no surprise that the elites of this sport have to be as hard as nails. This is the case of 27-year-old Brenda Martinez who competes in the Carlsbad 5000 on March 29.

How tough is Martinez? Here’s an example: Last month the UC-Riverside graduate was anchoring the women’s distance medley for the USA squad at the 2015 New Balance Indoor Grand Prix in Boston. Martinez got the baton for the 1600m leg at the same time as rival Nicole Tully. In the final 400 meters, Tulley surged past Martinez, but the race wasn’t over—not by a long shot. Martinez, didn’t give up, and kicked ahead of Tulley to break the world record for that event.

“It was amazing,” she now recalls of that race. “It’s always tough to be the anchor. I gave it my best. But I had lost track of the laps and the competitor in me had to come out to win it. The crowd helped carry me.”

The crowd will surely be there in full force on March 29 in Carlsbad, Calif., where Martinez, a world championship bronze medalist, will face some stiff competition. On the American side, she will square off against Deena Kastor. She’s the last woman representing the United States to win the race back in 2002 where she set an American record, clocking 14:42. Kastor is looking to break the Masters record in Carlsbad. For Martinez, it will be her third showing there.

“I just love it,” Martinez says of the race. “San Diego is beautiful. It’s close to my home and so I’m looking forward to local support.”

RELATED: Carlsbad 5000 Alters Its Elite Course

Obviously, Martinez, who has finished as top American in her past two showings, would love to win the race outright, but is realistic in setting expectations. “All I can give is my best,” she says. “My training is going really well, so I think I can be a lot tougher this year. There is always a point in the race where I’m saying to myself, ‘Oh, this hurts,’ but I’ve been pushing myself more this year. I really want to test myself.”

Martinez’s test in Carlsbad will surely come from Ethiopia’s Genzebe Dibaba, who set the world indoor 5000m last month in Stockholm. Dibaba is a two-time World Indoor Champion and a former World Junior Champion over 5000m. Carlsbad will be her first 5K road race, but she has posted an impressive 14:28.88 on the track.

Martinez hopes to be able to hang with the leaders up until the last part of the race where she will depend on that incredible turnover that got her the world record last month in Boston. “If I’m there in the final mile or even the final quarter than I will be really excited,” she says. She says she’s been putting in the miles—about 70 to 80 per week—and has maintained an excellent relationship with her coach, Joe Vigil.

In its 30-year history, the Carlsbad 5000 has been home to the 17-fastest 5K times ever run on the roads by women. Sixteen world records, 8 U.S. records, and numerous national and age-group marks have been set on the event’s scenic oceanfront course.