Quick question, It's been a while and I can't remember. I'm into my third week of the second block of training and my TSB has gone pretty far negative, around -40 to -45 this past week. How far negative do you guys go before you start to really notice fatigue set in and/or having sleep issues, get sick more often, etc? I have an interval workout planned tomorrow and Thursday, with a long group ride on Saturday, but that would drive my TSB well below -50.