Player position themselves on service line and volley across the court to one another.
Two balls are going at the same time so rallying pairs must concentrate hard to keep their ball going.
Which pair can keep rallying the longest?
"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.
As we enter the business end of the competition, we take a look at the remaining eight teams and the key talking points surrounding each side.