Running was my thing back in the day in gym class at school.(And I can still run fast today) I would've nailed it.
Unfortunately we didn't do the beep test in any of my schools, so this isn't familiar to me.
I did get into running in my 20s, and I could run fast, in fact my best time for a mile was just under 4 minutes.!!
But injuring my knees meant that I couldn't carry on and my fitness levels have plummeted.