Most workouts are hard and my brain tells me to quit. I have to be mentally strong to keep going and complete the workout, but when it’s done it’s obvious that it was by mind not my body that was weakest. You are more capable of digging deep and getting results than you think you are.
Most people hear about TR from the podcast, or a blog or a cycling friend. The refrain is the same “you won’t believe how much stronger and faster you will become on so little training time”. You don’t think that the gains come easily do you? They don’t. It’s hurts … a lot … every time. If it doesn’t, you’re leaving improvements on the table.
That’s up to you and your goals. I would say to push through. If you’re in dark place during a workout and just ignoring the pain won’t get you to the end 1) try to backpedal a few times (up to 10 secs, otherwise it’s a break not a rest) 2) decrease the workout by a few % (2-5%). You are better off getting to the end of a workout with additional rest or reducing intensity than trying to brute force it and blowing up half way.