No joke. Look, when I was in athletics in HS I did freakish stuff on occasion. We ran a X-C practice race my sophomore year against 2 other schools, I struggled to 22 minutes for 3 miles. We went to the first official meet 3 days later, I covered 3 miles in 16:41 in the JV race even after having to backtrack ~75 yards off a wrong turn. I got thrown in on the LJ relay to fill a spot at a meet as a junior and went 20’7", no wind. [And then never went over 18’4" the rest of the year, even in practice.] We’d do 16x400s on the track as “60 or less, or you’re out” and I’d often run the final one at 53-54. [Lifetime best in the open 400 was 54.6]
And yes, one day we did vertical jump testing and I tagged 39".