1 year post-op BBL. Can I lose volume if I exercise to build muscle?

Squats and lunges after a Brazilian buttlift will only increase muscle bulk and definition, which is probably a good thing in most women looking to achieve a more projected, lifted buttock.  However, just make sure that the body fat percentage is held in check or you will lose some of the fat, as you have stated. Keep an eye on your weight, and decrease the amount of exercise as warranted.Kenneth Hughes, MD, Board Certified Plastic SurgeonLos Angeles, CA

Hello dear!!
Thanks for the question and provided information as well. 
No matter if you have had a BBL or not, your body looses and gains weight in a proportional way. The important thing to do is to maintain a healthy life style after surgery, so you stay in a weight you feel confortable in and the results don't get affected. If you exercise your buttock, you will only define it and make it perkier.
Good luck :)