Suggested exercises for toning chest muscles are:

Chest presses - These are done laying flat on your back with your abs tight and your lower back flat. Start with weights directly over your chest with your elbows at 90 degree angles. Press arms straight up without locking your elbows, then lower your arms to their starting position. Repeat at least 10 times. Note: You don't have to have a weight bench or professional barbells to do chest presses. You can lie on the floor and use dumbbells, books, or even milk jugs full of water (they weigh about 8 pounds when full). As your conditioning improves, you can invest in a standard barbell set to allow gradual increases in weight or you can increase sets of repetitions.

Push ups - They aren't just for men. So, place your hands on the floor a bit farther apart than your shoulders. Get up on your knees or toes, slowly bend your arms and lower body until your elbows are at 90 degree angles. Straighten your arms and push up but don't lock your elbows. Keep your abs tight--don't sag in the middle. Slowly lower yourself back down. Repeat this 10 times. Rest for one minute. Repeat another 10 times. As your strength and conditioning improve, do longer sets and more repetitions.

Chest flyes - These are done by laying flat on the floor, abs tight and your lower back flat. Start with the weights directly over your chest, palms facing each other. Keep your elbows slightly bent. Now, lower the weights out to the sides, stopping at shoulder level, then bring the weights up again. The motion should resemble "hugging a tree." Be careful not to lock your elbows during the lowest point to avoid damage to the joint. Note: You don't have to have a weight bench or professional barbells to do chest presses. You can lie on the floor and use dumbbells, books, or even milk jugs full of water (they weigh about 8 pounds when full). As your conditioning improves, you can invest in a standard barbell set to allow gradual increases in weight or you can increase sets of repetitions.

Wall ups - These are done by standing about two feet from a wall, facing it. Place your hands at chest level flat against the wall. Now, lean slowly toward the wall using your arm and chest muscles to control your motion until you have your nose against the wall. Push back to your original position. Repeat this motion 15 times. To increase the effects of this exercise, when you reach the point of lean that stresses the chest muscles most (you'll feel it), pause and hold for a count of 10 or 15, then finish the motion.

In addition to targeted individual exercises, there are lots of activities that improve arm muscle tone and work to strengthen and define the various arm and upper chest muscle groups. Sports involving throwing a ball (i.e. baseball, football) and sports that use the arms and chest for power (i.e. rowing, tennis, squash) are all excellent ways to build, strengthen, and tone arm and upper chest muscles.