I have an online friend who just ran a marathon in 3hours 11 minutes. Obviously she had to train for that too, and she is currently 27 weeks pregnant. Does that help? LOL.

As i understand it it is actually very difficult to raise your core body temperature significantly with exercise - you sweat, this keeps you cool. If you could create a dangerously high temperature with exercise triathlete's and marathon runners would be delirious with fever by the time they finished.

My ob told me that if i managed to create a core temperature rise significant enough to harm my baby i would need hospitalising anyway for my OWN health. Why? Well, ever noticed how when you're PG you sweat more easily, breathe faster and have more skin (big bump + fluid retention + fat)? Your body KNOWS you're pregnant and takes that into account when you exercise. So if you used to jog for 2km before you began to sweat you might find you sweat a lot quicker when PG, not a sign that you're overdoing it, but that your body is protecting the baby like it should. As with pretty much all else with pregnancy, you just need to make sure YOU feel ok, and you can rely on your body to look after bubs. Studies have repeatedly shown no risk to the fetus's of women taking part in strenuous activity, but sadly many obs and midwives don't really know the facts and err on the side of caution.

Exercise as much as you want, talk to instructors of classes about what to do/stop doing. My pump instructor modifies the abs work as soon as you're showing and goes on taking ladies up to the 34th week. I walked 2 miles and swam 1 mile 2 days before DD was born (she came 11 days after her EDD). If you feel ok then you are.

Bx