As the obesity rate grows worldwide there is an ever increasing concern that adults and children are not active enough, and are concerned about the number of hours spent sedentary. More specifically, the number of hours people are spending watching TV and playing video games. That is where a distinction should be made but never usually is. Video games, although similar in nature, are not the same as watching TV.
Television
Throw a couch in the equation and the television becomes the symbol of the lazy "couch potato." Watching television is as sedentary an activity as anyone could imagine. Most people watch television as a way to unwind at the end of the day either after work or school, etc. So, of course, it makes sense that someone would just want to sit there and relax perhaps enjoying some munchies or dinner. But too long in the same position on a regular basis could lead to problems like obesity, muscle soreness, sloth, etc.
Video games
Like watching TV, playing video games involves sitting on a couch, chair, etc. for extended periods of time, but it is the lesser of the two evils. Video games virtually have the same effects on the physical body as television does but video games affect the mind in a different way entirely. Most games, especially competitive online multiplayer titles such as the "Call of Duty" franchise or "World of Warcraft," engage the player in a way that utilizes problem-solving skills, hand-eye coordination, focus, response rate, etc. Many studies have shown that playing video games sharpens the mind and instills the basic fundamental skills needed to operate unmanned, remotely controlled vehicles and machinery used in surgical teams, on the battlefield in war zones, etc. Not to mention that most games have a suspenseful, cinematically beautiful story that has the potential to rival that of shows on television. Video games have the potential to sharpen mental faculties in a beneficial way.
When should you take a break from the screen?
Nobody should be sitting in a chair or on a couch for hours on end. It is simply not healthy. A general rule of thumb to keep in the back of your mind is that if your bottom begins to hurt then you need a break. Of course, everyone is different so that time could range anywhere from a few minutes to a few hours. To quantify my general rule I recommend that everyone take a 15-minute break per hour of watching TV or playing video games. Staring at a screen for too long can cause your eyes to become irritated, someone to feel groggy, and staring at something for too can cause the eyes to adjust the perception of where that object is in space. Like how a zoom camera can be adjusted. Just keep in mind that no matter what activity you're engaged in too much of anything is never a good thing.