When we refer to someone as being "out of shape," there are a number of synonyms we could use. Someone might be described as being "unfit" if they are lacking in physical stamina or strength. "Flabby" implies lack of muscle tone or excess body fat. "Sedentary" suggests a lack of activity or exercise. "Inactive" or "sluggish" can be used to describe someone who lacks energy or motivation. "Unhealthy" may be used to refer to someone who has poor eating habits or an overall unhealthy lifestyle. Finally, "unathletic" could refer to someone who is not skilled or coordinated in sports or physical activities.