CINCINNATI, Ohio -- Coco Gauff takes great pride in her athleticism and speed around the court. So who does the 19-year-old think could challenge her on the track in a 100-meter dash?

"I think Alycia Parks, she's pretty quick, has a good stride," Gauff told reporters after booking her spot in the semifinals of the Western & Southern Open. "Iga [Swiatek] is pretty quick, too. I think those two would give me a run.

"I would be curious to test it, to be honest."

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The World No.7 chose tennis over track when she was younger, but the 400-meter race was more her specialty. Gauff's mother Candi also ran track at Florida State University. Maybe it's in the genes.

What's Gauff's secret to running a good 400?

"I don't get tired," Gauff laughed.

"Everybody said I should run 400. I was like, I'm not going to take one of my teammates' spots, this is actually their life, and this is just something I'm doing for fun. I'll just stick to the 800."

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Gauff has continued her summer surge in Cincinnati, where she advanced to her second WTA 1000 semifinal of the season. Just as she did in her title run at Washington D.C. two weeks ago, Gauff has yet to drop a set this week. She credits her improved for to a series of minor adjustments to her footwork and court position, as well as a more aggressive mindset. 

"I started tour so young, so I wasn't really strong enough to hit and close the point," Gauff said. "When I was in juniors, I was a very aggressive player, to be honest. When I played in the pros, the balls are coming a lot faster. Some things that are winners when I was in juniors is not winners in pros. So I really had to rely on [my defense] just to stay in these matches.

"Now I feel like I really have the strength and mentality to execute those offensive shots. I think that's where the mindset comes in."

Gauff is looking forward to testing her improvements against Swiatek on Saturday. The American has yet to win a set off the World No.1 in their seven previous matches. 

"I'm just really going to go out there and continue to follow the plan that I've been doing in the last couple of my matches," she said. "I do feel a lot more confident going into it tomorrow. 

"But she's not an easy opponent to play, especially against me. I think I really just got to take it point by point and try to stay mentally engaged every ball."