(especially reading and study material) Difficult to understand and enjoy.
(of a task) Difficult and requiring a lot of effort.
Source: en.wiktionary.orgI really love a challenge, but in 'Downton' it was really hard going because there's no CGI - what you see is what you get. These were real explosions right in front of our faces, and you just had to make sure that you cleared out of the way. Thomas Howes
It was extremely hard going from being a parent of one to a parent of three, because now all these instant decisions have to be made about how you balance out the time and attention between them. Patricia Richardson