I am doing the 12 week Build Me Up training plan. I am currently in week 5 (it is not a ‘rest’ week). I’ve noticed this week that even though most of the work is sweet spot work, my heart rate is not elevating the same way it was in the first 4 weeks. Now, riding at 80-90% of FTP doesn’t elevate my heart rate above 145-150 bpm. In the first four weeks my HR was easily above 150 and at times over 160.
Is this a sign that my fitness is improving and that I should increase my FTP? I’m fairly new to structured training plans so I don’t want the remaining 7 weeks to be too ‘easy’ but I also want to trust the plan. Any thoughts/comments are appreciated.