Most people with weight concerns are trying to shed pounds. But if you're naturally skinny with a fast metabolism, it can be just as much of a struggle to keep weight on your frame. If you're looking to bulk up your legs, you'll need to pair a weight-gain diet with an exercise program that promotes leg muscle growth.
Create a Calorie Surplus
People trying to lose weight eat fewer calories than they burn, but when you're trying to bulk up, the opposite is true. You'll want to create a small calorie surplus, so your body can use the extra calories to add bulk to your frame. Aim for 250 to 500 calories per day, recommends the McKinley Health Center. That will allow you to gain an average of 0.5 to 1 pound per week. Ideally, you'll want to gain most of your weight from new muscle tissue instead of fat.
Exactly how many calories you need to create that surplus will vary depending on your existing body composition, age and gender, and genetics. Online calorie burn estimates are just that -- estimates -- and if you're naturally thin, you likely have a higher-than-average calorie burn. If you're currently maintaining your weight, record your food intake for a few days to figure out roughly how many calories you're eating, then add 250 to 500 calories to estimate your new daily calorie goal.
If you find yourself gaining weight too quickly -- and gaining too much fat -- reduce your calorie surplus until you're gaining up to 1 pound weekly. On the other hand, if you're not gaining weight, gradually up your calorie intake until you're gaining 0.5 to 1 pound a week.
Power Up With Protein
When you're gaining weight to bulk up your legs, make sure you're getting enough protein. The amino acids that make up protein are also the building blocks of muscle tissue, so it's essential to support your leg-bulking workouts with enough protein for new muscle growth. Protein should account for between 10 and 30 percent of your calories during weight gain, according to Rowan College. If you're following a 3,000-calorie bulking diet, that means getting between 75 and 225 grams of protein each day.
For example, a three-egg omelet for breakfast provides 18 grams of protein. Snacking on five slices of turkey breast wrapped around pickle slices offers roughly 30 grams of protein. Including 3 ounces of chicken breast with your lunch adds about 24 grams of protein to your daily intake, and eating 3 ounces of salmon boosts your protein intake by 17 grams. A post-workout snack of a protein smoothie made with three scoops of whey protein isolate mixed into 1 cup of milk has 58 grams of protein. Altogether, that adds up to around 147 grams of protein -- you can scale the portion size up or down to meet your intake goals.
Choose lean sources of protein to stay healthy as you bulk up. Eat grilled turkey or chicken breast, lean cuts of beef, sole, tilapia, salmon, eggs, beans, legumes and nuts as sources of protein. You can also boost your protein intake with protein powder -- look for varieties that don't contain added sugar.
Ideas to Eat More Calories
If you find it difficult to eat more food, try simple techniques to boost the calories in your meal plan. For example, add a spoonful or two of almond butter and a container of Greek yogurt to your protein smoothie, mix an egg or two into your oatmeal as it cooks, and go for denser whole-grain breads; they tend to be more calorie-dense than lighter, airier breads. Drizzle roasted veggies with a healthy oil -- like extra virgin olive oil -- and top your salads with avocado to boost their calorie content. As you get used to your bulking diet, you might find you're able to eat bigger meals and meet your calorie goals more easily.
Train to Bulk Skinny Legs
Diet alone isn't enough to put lean mass onto skinny legs. You need a strength training program to trigger muscle growth; otherwise, the extra energy you're taking in will be stored as fat, which likely won't get you the physique you're seeking.
Strength train each muscle group two to three times per week. Bulk your legs by performing lower body exercises -- like squats, lunges and deadlifts -- using dumbbells or barbels. Different variations on these exercises -- for example, sumo deadlifts, plie squats or side lunges -- allow you to work your leg muscles from different angles to stimulate more muscle fibers. Choose two to three leg exercises and perform between two and three sets of four to eight reps of each exercise to gain weight, recommends the McKinley Health Center.
If you need an extra boost to add more muscle to your legs, consult a trainer for a personalized fitness plan. A trainer can assess your current fitness level and recommend a progressive plan unique to your physiology and goals.