Anyone staying at The Banff Centre, including BIRS participants in Corbett Hall, has free access to the Sally Borden Fitness facility upon presentation of their room key. It has an athletic complex with swimming pool, running track, workout room, climbing wall etc., all of which are available complementarily to BIRS participants.
The Banff Centre also has a very nice arts/music library which has a good collection of sheet music as well as recorded music and video material. BIRS participants are welcome to use this library, which is located in the Kinnear Centre for Creativity & Innovation.
As a centre geared primarily towards the fine arts, it could also be well worth looking into what is going on beyond BIRS for the times during which you are not participating in events directly related to your workshop. There are often evening performances of all genres. For more on the Banff Centre and its current artistic program, please refer to the Banff Centre webpage http://www.banffcentre.ca.