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?

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.