It is normal for teenagers to physically develop at different rates. Yet for young athletes participating in size-dominated sports such as football and basketball, weight gain often cannot come soon enough. Athletes in these sports benefit from the strength and power that added size can provide, but weight gain can be just as much a challenge as weight reduction. Develop a healthy weight gain plan, one that supports gains of 4 lbs. to 8 lbs. a month.
Determine your current caloric intake. Begin a weekly food journal and write down everything you eat and drink on a daily basis. Include the type of food, the amount consumed and the number of calories. You can find foods' caloric content on "nutrition facts" food packaging labels. At the end of each day, total the number of calories you consumed. After seven days, add your daily totals together and divide by seven to find your daily average caloric intake.
Add 500 calories to your daily caloric intake. This is your new daily calorie goal. If nothing else changes, it should enable you to gain about 1 lb. a week, or a little more than 4 lbs. a month. If you want to gain more, add more calories accordingly.
Divide your new daily calorie goal by six. This is the number of calories you will eat at each of six combined meals and snacks throughout your day. Eating frequent meals enables you to consume a greater amount of food without feeling overly full. Frequent eating also provides your body with a consistent source of energy to fuel muscle growth.
Plan meals and snacks to meet your new caloric goal. Select energy-dense foods that make it easier to consume additional calories. Energy-dense foods provide a lot of calories in a relatively small volume of food. Think peanut butter and other nuts, fruit juices, smoothies and dried fruits. For an 850-calorie meal, for example, include a peanut butter and banana sandwich made with two slices of whole-wheat bread, a medium banana and 2 tbsp. peanut butter; 1/2 cup baby carrots; 1/4 cup trail mix; and 1 cup chocolate milk.
Resistance-train. A carefully designed, full-body strength training program uses weight machines for exercises such as squats to work your legs; free-weight barbells for military presses, bench presses and biceps curls; and your own body weight for resistance while you perform crunches and other exercises that work your core muscles. The key to building muscle through resistance training is to use weights that are heavy enough that you can do only about eight to 12 repetitions in each set.