A sedentary lifestyle is a type of lifestyle with no or irregular physical activity.A person who lives a sedentary lifestyle may colloquially be known as a slob or couch potato. It is commonly found in both the developed and developing world.Sedentary activities include sitting, reading, watching television, playing video games, and computer use for much of the day with little or no vigorous physical exercise. A sedentary lifestyle can contribute to many preventable causes of death.Screen time is the amount of time a person spends watching a screen such as a television, computer monitor, or mobile device.edentary activities include sitting, reading, watching television, playing video games, and computer use for much of the day with little or no vigorous physical exercise. A sedentary lifestyle can contribute to many preventable causes of death.