Board Thread:Naruto Discussions/@comment-37357782-20190114234611/@comment-1872728-20190115095507

If you're talking about using Sage Chakra, from my understanding, you're still using up your regular chakra, the Natural Energy only strengthens your chakra. If you're talking about manipulating Natural Energy, I don't think Jugo can do that, because he didn't train in the Sage Arts.

So to answer your question, I don't think Jugo can fight forever, because he needs to recharge after he uses up his chakra, unless there's someone near him that he can absorb to replenish his chakra.