Heart Rate / FitBit Question, am I doing damage? Need advice from someone who knows....

[waterjungle]

Before lockdown I was spinning 2/3 times a week and had done for about 6 months, I was lucky to get hold of a exercise bike but it's not a spinning bike and seems a lot harder.
I am trying to do 3 times a week for between 35/45 mins.

According to FitBit HR monitor my heart rate is at peak 85 / 90% of that time, averaging 168 / 178 peaking at 185/190.

When I told my husband this is said I am going too hard and should slow down as it's not good to have my heart rate so high!

Yes, I am challenging myself but I though that was goo, if I can sustain it for that long is it bad for me or is it a good cardio workout? Am I doing myself harm? I feel like I've had a good workout afterwards and I'm not dizzy or faint. I always find it difficult to be restrained when I'm exercising and tend to be a bit "go hard or go home!" I think once I'm on it's like I've only got 30min so make it count!

I am 41, 5'4 and 9 stone 8.

My the is under 50, but when I run at pace, for 10k my heart rate goes to 180 and will be around 170-175 the whole time, yet I'm fine and can even sing along my music.

We're all different. What I've been told is to watch how quickly it comes down. Mine will go down to 130 in 20 seconds or less, and then 100 in another 10-15 seconds which is good.

Fitbit uses formula to calculate your max heart rate, it isn't always accurate as we are all different. Smaller females will usually have higher max rate than a larger male for example.

According to the formula, your max heart rate is 179, which is definitely not accurate if it goes up to 190. So it's probably quite a bit over 200.

Listen to your body rather than numbers and you'll be ok.