Lifting weights post Brazilian Butt Lift. Increase results or ruin results?

Sometimes residual swelling may last for a while.  You should have your surgeon take a look to make sure there is no infection or other problems.  If everything looks good, you may want to consider more aggressive massage to move out the swelling form those areas to allow the tissues to heal.  As far as exercise, you should be OK and your results will maintain as long as you maintain your fat %.   Losing weight and getting leaner will make your buttock smaller. Building up your gluteal muscles with exercise, will help to make it look better.

Exercising is encouraged after surgery.  Working on the muscle of the buttocks will further enhance your results.  The tenderness that you have is normal and should get better with time.  I don't recommend lymphatic massages, but if you find they are helping, continuing with them shouldn't hurt. 

Once you are fully healed from your BBL procedure, it is encouraged to lead a healthy lifestyle including exercises.  Core exercises and gluteal exercises will further improve your results over time.  Best wishes.