But what about going through a HIIT routine or keep rest low between sets to keep the heart rate high. IMO you cannot tell what your body is 'telling' you until

But what about going through a HIIT routine or keep rest low between sets to keep the heart rate high. IMO you cannot tell what your body is 'telling' you until you have pushed and 'suffered' to the point that you know when you body is truly hurt and when it is just feeling some resistance and telling you to stop that because it's too much effort. I know plenty of people who I have tried to train and work with who would give up on the first bead of sweat.