Handler vs runOnUiThread()

So after going through the chapter and learning about handlers. I started playing around with data from RSS feeds using the XmlPullParser and putting updating a simple UI. After some trial and error I finally managed to figure out where I was going wrong, but in my journeys to stackoverflow, I found the runOnUiThread() function.

So now I’m curious because the book didn’t talk about it.

Which is considered better programming practice? I can see how the handler gives more control options with the messages, especially between different background threads, but if you’re only updating the UI, is it better to use runOnUiThread()?