Summarize:

Although weight training can build muscle mass which consumes more calories and therefore increases your metabolism and improves your physique this cannot be viewed as getting rid of excess tissue in a specific spot. You'll need to be more active throughout the day and do some type of cardiovascular exercise. Simple changes like walking instead of driving or taking the stairs instead of the elevator can help you burn calories and fat. Consider wearing a pedometer to count how far you walk in a day. Combining weight training with cardiovascular exercise and a healthy diet can help you get rid of excess body fat, including in the chest area. Sensible weight loss is one to two pounds per week. Doing some type of exercise or activity five to six days a week can help you meet overall weight loss goals and get rid of excess breast tissue more quickly. Do least 150 minutes of moderate activity or 75 minutes of vigorous activity every week. Aim for at least 30 minutes of daily cardio to reduce breast tissue. Break up your workouts up into manageable sections if you're just starting. For example, try two 15-minute workouts. Choose activities that challenge your body and that you enjoy. It may take a little trial and error to find what works and what you like. Consider activities such as walking, jogging or running, rowing, swimming, or biking. You can also use machines such as an elliptical, stair trainer, or rowing machine. Keep in mind that team sports, running outside with your kids, or even activities like jumping rope or on a trampoline count towards your weekly exercise. Boot camps, spin, aerobics, and cardio burn classes that use free weights and other equipment are a great way to start building muscle and reducing fat in all areas of the body. They can also motivate you if you have a hard time doing workouts alone. Sign up for a class that you do three to four times per week, with a day of rest in between. These classes often have the added benefit of teaching you proper form, which you can apply when you work out at home or on the go.
Change your sedentary lifestyle. Do cardio most days. Take classes.