Without doubt, one of the most FAQ when discussing Application Pools in IIS Admin and Troubleshooting workshops!
Scott Forsyth shares Wade’s answer
In Wade’s words: “you don’t get a resonate pattern”.
then follows up with useful advice on establishing your own best recycling interval:
First off, I think 29 hours is a good default. For a situation where you don’t know the environment, which is the case for a default setting, having a non-resonate pattern greater than one day is a good idea.
However, since you likely know your environment, it’s best to change this.
Lots of useful information and commentary in a post that’s sure to become a genre classic. Really. No sarcasmo.