Yeah you just keep doing them. In highschool we would do them with our whole varsity team like 15 guys it made it longer we had to jog and farther we had to sprint when it was our turn thats how it works
Break them into like two or three groups depending on how many kids you have (or if they’re older keep them all together it only matters for how far they’ll have to sprint) they take off jogging around the perimeter of the field and u blow the whistle periodically when u blow the whistle, the last person in line has to sprint to the front while the others keep jogging and then keep doing that until everyone has gone once or twice or watever u want