Report with Value Prompts on Page Takes Awhile When It First Loads

[Blessed2]

I have multiple (about 7) value prompts that are directly on a report so that the end-user is able to pick and choose the data they would like to see.  These prompt are not required and they do not cascade off of one another and there is no prompt page.  The problem that I have is that when the report initially loads it takes about 2 minutes before you even get to the report.  In the database, this report is pulling from about 300,000 records.  So, because there are no filters before the report loads, it is choosing all of the records.  I tried to just choose one of the value prompts fields and set a default selection.  This worked and the report had something to filter on at the beginning making it run faster BUT it maintained the default selection if you did not specifically choose to change it.

Here's an example.

I open the report (which takes about 2 minutes to run).
I have the following value prompts:
*Employee name
*Employee badge
*Location
*Position
*Course

If have a default selection filter on Course. So it is filtering by course on the intial load (takes 15 seconds).  The report comes up.  So I go in to choose a specific employee and I want all of his courses so I don't choose anything else, it will still filter by whatever the default selection is on course even if I don't choose anything in that field.

So I was wondering if anyone knew how to get the report to run faster in the initial load.  I know that reading 300,000 records takes a little time, but because Cognos is an enterprise level reporting tool, there must be someway to handle or bypass this issue.    Thanks in advance for your help.