I can't tell you if that is normal or not for you. What does your heart doctor say? Emphasis on heart doctor, because my regular doctor seems to evade the detailed questions I ask about HR as related to riding bikes. Perhaps my heart doctor rides a bike and knows where the question is coming from.......

I ride little to none for three to four months a year... gets dark too early, cold, I don't like it. It takes me a couple months of pushing to get back to where I was previously. If I didn't push and put up with the feeling tired the rest of the day, then I wouldn't get to the level where I feel great and invincible....... which might be why my skull got cracked in a few places last year. But that's another story.