I had to quit the build phase in the final week because I’d made myself ill. Also it was affecting my weekend outdoor rides because I was still carrying fatigue from the week of training. I also commute 24 kilometres four days a week and weight train three days (squats, deadlift etc) so my TR training was coming on top of that. That might not sound a lot, but I’m 43 and until recently it felt like I had permanent Delayed Onset Muscle Soreness.
I stopped TR for a couple of months and then gradually worked my way back in. I don’t do plans, just one workout a week. It’s plenty for me on top of my other activities and, if anything, I’m fitter than I was during the build phase. My FTP is actually slightly higher.