How can I help my breasts regain elasticity during weight loss?

Thank you for your question.  This is a great question and one of the holy grails of plastic surgery.  Unfortunately, in 2015, there is no way to increase the elasticity of the skin.  Best to wear supportive bras.  Sagging of the breast can only be corrected surgically.

First off, amazing effort with loosing weight.  Exercise has multiple benefits for the body and its nice to see you being proactive about your health!  Unfortunately, there is nothing you can do to help the breast skin shrink back or prevent sagging.  Genetics and age will determine how much elasticity the skin will spring back when the breast volume diminishes.  Since you are still very young, you have more elasticity than someone that is older in age.  But there is nothing you can actually do at this time to make it better.  Continue to wear supportive bras and give it some time to see what happens. Good luck!- Dr. Roger Tsai

Congratulations on your decision to maintain a healthier lifestyle and losing some excess weight!  As part of that weight loss, women often experience loss of volume in their breasts as well and that is likely the case with you.  You mention that your breasts were already pendulous and that you are 5'4" and 135 pounds with a previous H cup bra.  As you get older and your breasts have developed completely, you may wish to have a breast lift and perhaps reduction to make your breasts more proportional to your body size--this will take care of the excess skin, lift the breasts and perhaps make exercise even easier with smaller breasts that are not as heavy.  Unfortunately, skin elasticity varies from person to person and there's not a whole lot you can do to increase the elasticity.  Best of luck with your continued healthy lifestyle!