Is it impossible to keep up with this series if I start now?

They only come out with a new one once a week or once in two weeks so all you really have to do is watch at least two episodes a week and eventually you will catch up. Just don't watch the fillers, they are boring and worthless. Watching the show is for the enjoyment of watching it so I don't see what the point of starting later into the series would be. You may as well start at the beginning unless you're in some kind of hurry to be caught up with the plot of the show. Really you could just read a summary of what happened and start with shippuuden or something.