Exercise can help people shed weight, but it can also help others gain weight in a healthy manner. If you’re underweight, you may need to gain weight to build muscle or if you’re underweight, which means you weigh less than is appropriate for your height. I’m not sure if you’re underweight. To find out, use this body mass index (BMI) calculator. We’ll cover some exercise tips for gaining weight with minimal equipment that you can use right now. We’ll then discuss how to build lean body mass. Female and male bodies store fat and mass differently. Focus on the exercises that produce the most beneficial results for your body type.