Toning your underarms involves a weight-training program that targets the muscles in the area. It is important to note, however, that weight training alone isn't likely to be enough to improve the appearance of your arms. Combine weight training with cardiovascular exercise to burn fat from under your arms and a healthy diet to control weight, suggests the Centers for Disease Control and Prevention. Many exercises are available for activating the muscles in your underarms, allowing you to mix and match to create a workout that works for you. Talk to your doctor before starting a new eating or exercise program.
Choose the right size weights. Do a set of 12 repetitions with a specific pound load. If the final two or three repetitions are difficult, but you can finish with good form, you have the right weight. If you can't finish the repetitions, your weight is too heavy. If the set is too easy, your weight is too light.
Do at least one set of 12 repetitions of each underarm exercise at each session. This is the minimum recommended by MayoClinic.com to see results in a couple of weeks. Adding a set or two speeds your progress.
Lift weights two or three times each week. This helps tone your underarms, but allows your muscles a chance to recover and increase in mass and strength.
Allow a day of rest between underarm workouts. This prevents injuries and allows your muscles to repair themselves.
Choose exercises that work the underside of your arms. The muscles at the back of your arms are the triceps, so look for moves that work the area. Good choices include triceps dips, triceps extensions, dumbbell bench presses, triceps kickbacks, body weight dips, pushups and chest presses. Combine these moves with those that target the other muscles in your arms, which prevents muscle imbalances that could lead to injuries and a disproportionate appearance.
Include two and a half to five hours of cardiovascular exercise each week. This type of exercise burns calories and eliminates fat, uncovering the muscles in your underarms. Choose moves that activate your underarms to enhance the benefit. Biking, tennis, basketball and swimming are good choices.
Eat a variety of foods from each food group. This ensures that you are getting the adequate nutrients to fuel weightlifting as well as helping to get rid of fat on your underarms. Of particular importance are complex carbohydrates, which provide your body with energy for exercise. Whole grains, fruits and vegetables are the best sources. Protein is important for helping your muscles recover and stay healthy for lifting. Lean meats, low-fat dairy foods and beans are good choices.
Eliza Martinez has written for print and online publications. She covers a variety of topics, including parenting, nutrition, mental health, gardening, food and crafts. Martinez holds a master's degree in psychology.