Will regular exercise increase bodys blood volume? have pots and want to improve.

Yes it will: Increase blood volume. Can't predict if this will improve your symptoms but volume expansion key in pots or oi. Good luck & keep up on salt & hydration too.

Increased plasma...: Increased plasma volume is a consistent and natural adaptive response to regular physical activity. Period. Whether it will help your situation is unknown, but i would give it a try. Certainly, the exercise is beneficial!