I have not had any problems swimming in my sports bra. I did a 1/2 ironman last summer and wore the sports bra under my wetsuit - with no problems at all! I also thought that it might not be very comfy to run in my bike shorts but it is also fine. I always make sure that I have a running hat in the transition area too.

As I said earlier - not a lot of support in some of the tri suits.

I also have put together a packing list if you are interested! There is so much gear involved. But it has been a fun new adventure for me.