I am 26 weeks now! Using my back wrap for workouts has been both helpful for feeling supported in my lower back, but also for the cooling effect. I have recently "popped" and I am getting significantly bigger as the baby has been growing. Because of this it's easy to have bad posture during work outs. Also, I am starting to notice an increase in my "achy back".
I recommend using the back wrap if your going to be doing your pregnancy workouts!