Large arm muscles can be the result of heavy participation in exercise or sports -- including basketball, baseball and swimming. If you do not desire large arm muscles, you may have found that losing arm muscle can be a difficult task -- especially since you cannot specifically target the loss of muscle or fat to one particular portion of your body. While you can't really lose arm muscle, through a number of different exercises, you can develop smaller, more toned arm muscles.
Participate in strength training. The National Academy of Sports Medicine recommends strength training occur two to three days per week for 30 minutes at a time.
Complete body-weight exercises. Perform pushups and pullups. Complete high repetitions -- perform three sets of 15 repetitions. Body-weight exercises can help keep your muscles defined without losing a great amount of muscle tone.
Use 3- to 5-lb. dumbbells. Perform triceps and bicep curls and extensions with light weights. Performing three sets of 15 repetitions can help you burn calories, reduce the size of your arms and prevent your arm muscles from becoming flabby.
Participate in regular cardiovascular exercise. Cardiovascular exercise can help you lose any excess body fat that may be causing your arm muscles to look larger than you desire. The National Academy of Sports Medicine recommends 30-minute sessions of cardiovascular exercise, five days per week. Cardio can include sports, running, jogging, aerobics, cycling, swimming, dancing, brisk walking, gardening and household chores.
Reduce your protein intake. Your body uses protein as fuel during exercise. If you reduce your protein intake, your body will begin to burn your muscle tissue as fuel to use during exercise and daily activities.