Lead and trailing runs switch and go again. 180' forward sprint at fast speed. Repeat without a break. Maybe have a coach count numbers aloud as players sprint full-out 90'. Then ask them all to multiply their count by 2 and try to reach the same goal in that longer count.
Team sets out on jog in single file.
Trailing runner sprints to front of line. As he moves in front and slows, next trailing runner kicks in. Jog back to starting point. Repeat, with no break.