If you used IIS server or Windows Hosting, you might know an annoying problem that if your website not be visited for while, the next visiting needs longer loading time, you have to wait up to over 60 seconds if your hosting is not good. This is because IIS has a feature for low traffic websites it recycles unused worker processes.
The <periodicRestart> element contains configuration settings that allow you to control when an application pool is recycled.
The <recycling> element contains configuration settings that control the conditions that trigger IIS 7 to restart an application pool.
Internet Information Services (IIS) can be configured to periodically restart worker processes assigned to an application pool, which recycles faulty Web applications. Recycling keeps problematic applications running smoothly, especially when it is not feasible to modify the application code.
The following are some links about first loading performance on IIS (Windows Hosting):