(The Best Years in Life) Leg and other bodily injuries shouldn't stop you from exercising and strengthening your legs, provided you workout with greater care in the future. Rest after an injury of any kind allows your body to heal and regenerate, and regular exercise to rebuild strength is part of the process of healing. Consult your doctor or physical therapist before starting a new exercise routine after an injury, and never continue exercising if it hurts your back, legs or other injured areas of your body.