I found this on Sherdog and youtube, I think it might be a great workout. Its a portable speed bag pull up bar that fits in a doorway. Would it be a good circuit to do rounds on the speed bag supersetted with sets of pull ups? So you would do three minute rounds on the speed bag, then sets of pull ups, then back to the speed bag, what do you think? Here's the clip

https://www.youtube.com/watch?v=ckDl81UrGVo