You don't need a weight stack to build leg muscle -- your own body weight will do the trick. Moves that target your calves and thighs will lead to stronger, better-toned legs. Body type also comes into play, however, and some people will have slim legs no matter what exercises they do. If you're underweight, you may also need to gain body fat to achieve the thicker legs you're after.
Perform one to three sets of 12 squats. These rock your calf, shin, buttock and thigh muscles for serious toning. Stand with your feet just past hip width and your arms by your sides. Bend at the knees and hips simultaneously to lower your body until your thighs are parallel to the ground, keeping your back as straight as possible. Pause for a couple of seconds, then push down on your heels to rise back up to starting position.
Perform one to three sets of 12 lunges on each leg. Lunges work your whole leg along with your hips. Stand with your feet close together and lift one foot up as though you are about to take a step; pause for a second and balance on the other foot. Step forward with the raised foot about two feet ahead, landing on your heel. Bend both knees to 90-degree angles, pause for a couple of seconds, then push back to starting position.
Perform one to three sets of 15 stepups for each leg. Stand a few inches in front of a step or platform and place one foot on top. Shift your weight to the raised foot and step up with the other foot so you are standing on top of the step. Step down with the second foot and repeat. The taller the step or platform, the greater the muscle-building power.
Increase calorie intake if you're underweight. For weight gain, ShapeFit.com recommends a simple calorie-estimating formula: Multiply your weight in pounds times the number 18. So at 110 pounds, you'll safely gain weight eating 1,980 calories per day. This is not an excuse to pig out on doughnuts, however: Choose healthy, calorie-rich fare such as nuts, granola, eggs, avocados, low-fat cheeses and dried fruits. Sip on smoothies between meals, but don't drink any liquids while eating to leave more room for food.
- Perform strength training three times per week for best results.
- Allow at least a full day for recovery between strength-training workouts.
- Speak with your doctor before starting a new fitness plan.
Nina K. is a Los Angeles-based journalist who has been published by USAToday.com, Fitday.com, Healthy Living Magazine, Organic Authority and numerous other print and web publications. She has a philosophy degree from the University of Colorado and a journalism certificate from UCLA.