user_associated_blogs_loop.php

<?php
// Get the users blogs and loop through them
$blogs = get_blogs_of_user( $user_id );

foreach( $blogs as $blog ) {

	switch_to_blog( $blog->userblog_id );

		// Update the post count array with post count from each blog
		$network_post_count[] = count_user_posts( $user_id );

	restore_current_blog();
}