Shrink release the unused space from the databases.
There could be multiple reasons your report is running slow.
Either improper/bad/missing index,
bad queries.
to reclaim the space first check the db log size and data size separately
Pramod
SQL Server DBA | MCSE SQL Server 2012/2014
in.linkedin.com/in/pramodsingla/
http://pramodsingla.wordpress.com/