The Canberra Heat must beat their fiercest rivals, the AIS, on Wednesday if they are to keep their Australian Volleyball League title defence alive.

The local derby is not so much about cross-town rivals as it is training partners - both are based at the Australian Institute of Sport.

''We train at the same venue, we often train together, [the players] know each other on and off the court, so it's quite intimate in that sense,'' Heat coach Ben Hardy said.

''We know each other's games … we know just about everything about everybody in the gym, so it's unique in that sense.''

Both teams enter the round on four-match winning streaks, with only a set separating them on form. The AIS won their last match in five sets, and are in fourth place but the Heat will leapfrog them if they win.

''I don't expect anything less than a close tussle, it's always been close, we've had scrimmages that have always been close, we've got up on various occasions and they've got up on others,'' Hardy said. ''You can't predict how this game's going to go … it's really like a grand final.''

Both the Heat and the AIS will be fielding a full-strength squad.

''The keys for us will be our errors, they generally make more errors than we do but they've also got bigger, stronger taller players, so they've got their strengths as well.

''They train every day together, we don't have that luxury.''

The volleyball action continued this weekend when the ACT hosts the Good Neighbour Tournament.

The Canberra Heat Men and Heat Women will be among the 108 club teams from around Australia.

WEDNESDAY

Canberra Heat v AIS, 7pm at the AIS Volleyball Courts.

SATURDAY and SUNDAY

Good Neighbour Tournament: AIS, National Hockey Centre, National Netball Centre and the ANU.