Just install this plug-in, speed up loading YouTube videos at your posts.
By converting embedded YouTube videos to thumbnail images, you can shorten the loading time.
There is a setting that can conditionally disable the plug-in. * The number of embedded videos is within the setting value. * Put inside some tag has “disablethum” class.
At Edit Post view, you can use QuickTag for div tag has “disablethum” class.
This plugin is available for download to be used on your WordPress self-hosted installation.