Do Chest Exercises Decrease Breast Size

If I strength train my chest muscles, will this decrease the size of my breasts? Please say it won’t!

Good question. Those of us who spent their adolescent years with noses buried in Judy Blume novels hoped that exercise, and by that I mean the elbow pulses that accompanied the chant, “we must, we must, we must increase our bust,” from Blume’s classic novel Are You There God? It’s Me, Margaret, would increase the size of our chests, not shrink them. And the truth is, any exercises you do to work that area will not make your breasts smaller if you are currently of a healthy weight. In fact, exercise may enhance their appearance.

There are two muscles that make up your chest: the Pectoralis Major and the Pectoralis Minor (your pecs). The Pectoralis Major originates from your breast bone in the center of your chest and attaches to your humerus, near your shoulder. The Pectoralis Minor muscle is underneath the pectoralis major, originating in the ribs and attaching to the scapula (shoulder blade).

The female breast contains mammary glands (modified sweat glands that produce milk when a woman is lactating), adipose tissue (fat cells) and fibrous connective tissue that gives your breast its shape. The nipple is connected to the mammary glands. Breast location is between the first and sixth rib, which are outwardly connected to the intercostal muscles (down the side of your ribcage) and the pectoralis major.

Resistance training (i.e. weight lifting, isometrics, etc.) increases your metabolism (the rate at which we burn calories), which results in a decrease in overall body fat (remember, there are fat cells in your breasts). Increasing your metabolism reduces the size of your fat cells, but it cannot spot reduce. However, if you lose a significant amount of body fat, you may notice a reduction in breast size, but this reduction will be proportionate to fat loss from the entire body (which is generally a good thing).

A well-rounded exercise routine will blend cardio 3-5 times a week (for at least 20-30 minutes) and include resistance training for all major muscle groups, including your chest. Training your chest muscles in a variety of exercises, such as push-ups, will enhance the shape of your chest over time. Strong chest muscles will support your breasts and help keep them up where they belong (like a portable bra you don’t have to take off!).

For more information on fat loss, check out the Top 5 Fat Loss Myths from And read this post on the many benefits of the push-up.