Do your boobs bounce? Then you are definitely wearing the wrong bra. 80% of women wear the wrong size bra. You must make sure that you get yourself fitted correctly. Go in and get fitted. Then, try a few different sizes close to what you were measured at. Some women have smaller backs; therefore, they to try one cup size up and one band size down. For instance, if you are measured at a 38D and you have a small back, try the 36E also. If you have a large back, you want to try a band size larger and a cup size smaller. For example, if you measured at a 38D, you may want to try a 40C too.
If your boobs still bounce a lot with the correct bra size. You may want a different style bra. You may want a full coverage bra. They have extra material support to fully encompass the girls. You definitely do not want to go with a shelf or demi cup bra if you are worried about the bounce.
To get the best support, go with a sports bra. There are some women that wear sports bras every day. They are designed to handle motion. They are not concerned with fashion like most bras. They have special features to keep the girls in place. Some sports bras compress and others fully encapsulate each breast. The main purpose is to stop bouncing and support the ligaments, tendons, and breast tissue in your boobs. Sports bras are specifically designed to handle any type of activities.
If you do not want to wear a sports bra all the time, you need to still protect your chest. The best bras for support besides the sports bras are the molded under wire full figure bras with strong bands, wide straps, and side slings. At the very least for all your bras, you should have a good quality band. The majority of your support comes from the band. Make sure that the band fits properly with room for an index finger snugly and no riding up the back. It should not be snug enough to have back fat hanging out.
As a woman, you do not want to have a lot of bounce. You can damage your breast tissues and you will sag earlier than your time. You need to protect the girls. Get fitted. Try a few different bras. Bounce around in the dressing room to make sure the girls stay in place. Buy sports bras. If you want variety, at least make sure that your bras have a good solid band that fits. Style is good but breast health is great for a lifetime. Make sure to limit your bounce. You will be uplifted for many years to come.