Here is a question Regan posted on facebook:
"Do you think boxing will increase bowling speed? I thought because it's training your rotator cuff to fire quickly that it might increase the speed."
The answer to that question is both complex and simple. And as this is a quick tip, I'm going to give you the shortcut first.
Boxing will help with bowling speed a little, but it's not the magic pill to being able to hurl the ball down at 150kph.