I am about to start a training plan in the next week, which will be probably 7-8 weeks in duration. Is there a recommended Optimum range for my TSB To be at on the day I start the plan? Ie how fresh should I be for day 1.
If you can start the plan after a rest week you will be good. Being at -1 you should be fine.
It’s still early enough in the week now to make sure you do not over do this week. Some short rides with some intensity is fine. Try to keep volume down and you will be set.