Prague. What a place. I’ve never been, but I’ve heard it’s lovely. World class architecture. Kind Czech citizens. Sausages so plentiful and tasty I’m getting angina just thinking about ‘em.

But for fifty or so very fast men and women descending on the ancient European capital this weekend, no such earthly pleasures will be partaken in. The 2017 Sportisimo Prague Half Marathon may be on April Fool’s Day, but the joke’s on you if you think athletes like fancy dog Galen Rupp have anything on their agenda besides lowering Ryan Hall’s American Record for the distance.

Hall’s mark of 59:43 was set ten years ago in Houston, Texas and though Hall’s career saw him put up marathon times Rupp has yet to approach, Rupp is undoubtedly the more decorated of the two. With two Olympic medals to his name, plus a 26:44.36 10,000m PR to boot, Rupp seems well positioned to run in the mid 59:30s this Saturday.

Forecasts call for a clear day with temperatures in the mid 40s at starttime. Couple that with a field comprised of men like Kenya’s Leonard Patrick Komon and Barselius Kipyego (both of whom have run faster than Hall’s 59:43) and you’ve got yourself a recipe for a fast race, on a course that’s seen Ethiopia’s Atsedu Tsegay run 58:47.

Rupp’s coach, the recently controversial Alberto Salazar, doesn’t take his charge’s racing schedule lightly. We rarely seen Rupp out of top form, or in a field where he won’t be near the front. The fact that Salazar’s flown Rupp to the Czech Republic undoubtedly means he’s ready to pop off a fast one.

Counting Kipyego and Komon, there are nine men in the field who have run faster than Rupp’s current PB, 1:00:30, but only one with a faster 10,000m best. Rupp is coming off of a spring season that saw him take to marathon training quite well. Hall’s AR is fast, and we shouldn’t overlook how good he was at his peak. But this is the best shot an American’s had at breaking it since then.

Keep in mind, Rupp hasn’t raced in 2017 and pulled out of the Houston Half Marathon with plantar fasciitis.

The women’s race is just as interesting from an American perspective. Salazar’s other spritely blonde protege, Jordan Hasay, is a part of a slightly less deep but just as front-loaded women’s field, headlined by Violah Jepchumba and her 1:05:51 PB.

Hasay just recently debuted in the event, running 1:08:40 in extremely soupy conditions in Houston this January. Times across the board were slow, so there’s no doubt Hasay was capable of faster. The question is how much? And the appropriate follow-up question is by how much has she improved since?

Deena Kastor’s AR, 1:07:34, has stood for over a decade. Not even Molly Huddle has dipped below, though she sits at second on the all-time list for American half-marathoners.

Could a lack of humidity, improved familiarity with the event, and two months’ worth of additional fitness gains allow Hasay to crack it?

On a good day, I wouldn’t be surprised to see her get close. The biggest thing working against her is the depth of the women’s field. After the seemingly untouchable Jepchumba, you have two of her Kenyan countrywomen who have run in the 1:06 range, then two women who have run in the ballpark of 1:08, Hasay included. After that things drop off a bit.

If Hasay can lock into a small pack of women running the appropriate pace, without getting dragged along too fast, or falling into a slower group, it’s entirely plausible Salazar’s athletes could fly home having monopolized American half marathon records.