Anyone have any guidance or rules of thumb on when to give up on a training session with regards to power output. I'm currently in week 3 of my training period and found I simply could not produce the same power during my intervals as I could a couple of weeks ago in week 1 (no power meter in week 2) when I was obviously fresher having just come off a week of reduced time/intensity.
I've read Hunter Allen's advice on percentage power drop based on the third interval but I'm trying to determine if it's better in the longer term to persevere with a planned workout even though I'm not producing the watts I'm aiming for or, should I do as I did today where I simply stopped very early after I determined I wasn't going to get close to the output I was aiming for and reschedule for tomorrow, or drop the workout for this week to ensure that I don't become too fatigued in the short term.
What sort of power reduction, if any, is worth persevering with in order to continue physiological adaptations in the right direction rather than simply grinding yourself into the ground and possibly underperforming for an even longer period?