@quilly I exercised during my pregnancy as well, running till 24 weeks (i would have ran more but I developed spd), weight lifting - deadlifts, squats&all, everything that felt good. I could only walk during the last 3 weeks as my spd got worse. I am also a doctor - gastroenterologist and read a fair amount on the subject. I am pretty confident that the HR limit is arbitrary, I wasn't overly concerned. It's actually difficult to keep it below 140 if you want to break a sweat. Those studies were done on women with fever, and extrapolated to exercise. I think it's great to have an active pregnancy if no complications and obviously do what feels good for you.