Jenny Simpson vs. Shannon Rowbury is one of the better rivalries we have in track and field. While we’ve never proven that the two women genuinely dislike each other, it’s clear they love nothing better than besting each other on the track.

At the Millrose Games in 2012, Simpson edged Rowbury in a fairly tactical 1500 meter contest.

Best line of the commentary: “You got to see the grit of Jenny Simpson on display.”

But it was really in the years to come when the action on the track — and the words off of it — really heated up.

After Rowbury claimed the American 1500 meter record in 2015, Simpson discussed Rowbury sitting-and-kicking on her en route to the American record.

“Shannon and I have not got back and forth,” Simpson said after that race in Monaco. “Shannon hasn’t beaten me in years.”

Rowbury responded with a more veiled statement, saying, “I’ve never thought of her in a category as better than me.”

Simpson may have gotten the last laugh at the 2016 Rio Olympics, where she won a bronze medal while Rowbury was just a spot behind but out of the medals.

Sadly, only Rowbury will be racing at Millrose this weekend but the field she’ll face, which includes the likes of Kate Grace, Brenda Martinez, Sifan Hassan and Amanda Eccleston (read our Q&A with her here), should make for a helluva race.

Want more Millrose Games videos to kill time on your Thursday? USATF.TV has a valuable archive.