The idea of keeping muscle mass while also losing weight may be foreign to you. Your muscles provide a framework for motor skills and physical activity. If you were to lose weight without training your muscles, it is possible you would lose weight from muscle loss and negatively impact your overall physical health. Fortunately, if you add strength training to your fitness program you will not only keep your muscle mass while you lose weight, but you will also burn more calories and fat with the added muscle you gain.