So today I did a 6 hour ride in the lower two power zones. But my HR was almost near the threshold zone! Temperature wasn’t high, pleasant even. Hydration was ok about 750 ml per hour. My max HR is 200 ish and I did 153 AVG for 6 hours. I had about a week off and did two weeks with 63 hours of riding for vacation with about 1000 TSS per week. My normal TSS per week is about 600 with structure and free rides.
Does anyone have a clue what’s coming on?