USATF Coaching manual

I was just looking through the USATF Coaching Manual, I was wonder what are they talking about in the sample workouts, “Turn-around 40m or 50m sprints”?
Any help will be appreciated

Thanx

I don’t have it in front of me at the moment, please provide more context from the paragraph it was in.

It’s a lactic workout. You run 40/50m, turn around and immediately do it again.