ASP.Net - Entity Framework - Applicatiopn slows down after inactivity

I am building an application in ASP.Net C# using Entity Framework. I have deployed it on IIS7.5

When I restart the IIS, first time it takes quite some time to display login page ( i consider it warm up time .. am i right? ). Then it starts working as normal. But if I leave the application opened for another 10 to 15 minutes without doing an开发者_开发问答ything, and then I use, it behaves in same way. It takes too much time ( around 15 to 20 seconds ) to refresh the page which next time takes only few seconds.

What could be cause of it it?

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This is probably the Application on IIS timing out when there is no activity, and then having to restart when there is activity. Take a look at the Application and Session time out properties in IIS.