Heart rate and exercise?

An abundance of caution. There actually isn’t a lot of evidence that high heart rate during exercise does anything bad to a pregnancy.

It's a old wife's tale as far as I understand

Because the baby’s heartbeat goes up when yours does and it can stress the baby.

My doctors told me super high starts to move blood away from the baby. So he recommended to me nothing over 140 for long periods of time. Iv been doing a lot of walking and yoga. I used to do a lot of running but as I get larger it’s a lot of weight to be pounding on the treadmill 😂