Players will find a straight line on the court.
Standing facing the line, players will jump off 2 feet back and forth over the line as quick as they can for 30 seconds.
World Rugby has reportedly conceded Aaron Smith's disallowed try in the World Cup final should have stood.
"It is not only useful for staff who are experienced but a valuable tool for those subject staff who have to take teams."
The variety of sessions across sports - sometimes we steal session ideas from one sport and use them with another.