Will bicycling after having a Brazilian Butt Lift procedure done shrink or enhance the buttocks?

The pressure from the seat on the fat may be an issue, and I would recommend that you ask your surgeon about recommendations.

Hello and Great Question.  I appreciate the time you are spending researching this procedure.  My name is Dr. Matthew J. Nykiel.  I am a Board Certified Plastic Surgeon, a Fellowship Trained Cosmetic Surgeon, and a Butt Augmentation Specialist.
You should speak with your surgeon.  He/she is your best source of information.  I would not want you on the bicycle for at least 4 weeks.Best of Luck!  
Matthew J. Nykiel, MD#TopREALSELFDoctor#CoreREALSELFDoctorButt Augmentation SpecialistLiposuction SpecialistBoard Certified Plastic Surgeon

As an avid bicyclist, I can tell you that bicycling is no different than any other sport; if you are worried about sitting on your fat cells, do  no worry as the fat that is placed in your buttocks is not where you sit on the bicycle seat.