If you're doing push-ups in hopes of gaining breast size, don't stop -- even if it doesn't quite have the effect you intended. Push-ups are a fantastic, functional exercise that contribute to healthy muscles.
Yet, even if you add chest presses and incline flyes to your workout, your boobs aren't going to appear notably larger. Women who undergo an intense muscle-building training routine might experience an increase in the size of their chest muscles — especially if their workouts are combined with the right diet and vigorous schedule — but muscle growth doesn't actually increase bra cup size.
Women's breasts are made up primarily of fatty tissue, not muscle. Increased size in your breasts happens when you gain weight, and the fat cells expand. Push-ups and other chest workouts affect muscle tissue. An intense, focused size-building regimen may increase your chest's muscle mass, but no exercise, including push-ups, is actually increasing the amount of fatty tissue you have there.
A Push-Up's Purpose
Push-ups work your chest, arms, shoulders and core. They help you become stronger and develop good posture by making your muscles and core stronger, so you stand taller and more confidently.
When done as part of a total-body, strength-training routine, push-ups help you develop size in your pectoralis major, a large fan-like muscle that makes up most of the chest wall.
Your breasts sit on top of this muscle. As a result, if you considerably increase your chest muscle size, your breasts may appear bigger because they sit on a higher, broader platform -- the breast tissue itself hasn't grown, though.
Read more: What Do Push-Ups Do For Your Body?
Muscle Growth Takes Work
Don't be afraid push-ups will augment a bra size that's already generous. It takes a lot of hard work to add such notable size to a woman's chest. Women lack the same hormones that promote huge gains in muscle mass that men can achieve, especially in the upper body. That's not to say a woman can't become muscular, and even "big," but it will take a lot more than push-ups to get you there.
To gain significant muscle, you must commit to weight training with heavy resistance at least three times per week. You'll need to train your whole body, not just your chest. Only through total-body workouts will you produce enough growth hormone to induce significant muscle mass gain.
Your diet also plays a pivotal role in muscle gain. The IDEA Health and Fitness Association explains women need at least an additional 150 calories daily to support muscle growth. Many of these daily calories come from protein sources -- aim to consume at least 1.6 grams of protein per pound of your body weight daily.
How to Make Your Breasts Bigger
Your breast size is determined by genetics. Hormonal changes during the month and with pregnancy may cause your breasts to swell as it affects the duct and lobule volume, but these changes will not last. Short of surgery or notable weight gain, a significant change in your breast size isn't possible.
Read more: What Causes Breasts to Get Bigger?