A few years ago when I got my first job as a programmer, I was given a small booklet that had a list of all the different exercises that we were supposed to do at regular intervals. The exercises included stretching arms, legs, walking around, closing eyes, shoulder and wrist exercises. All of these were supposed to prevent various health problems that are associated with sedentary lifestyle and working in front of a desktop computer for many hours everyday.
If you want to be reminded of taking a break and do some of these beneficial exercises then you can make use of a free software called FadeTop. It is a reminder application for Windows users. It can remind users of taking a break at regular intervals. The reminder is designed to be completely unobtrusive – it does not blare an audible alarm or flash some neon text on your screen, it just gently fades the computer screen into a specified picture or color.
In the options of FadeTop, you can set the number of minutes of activity after which the reminder is shown – it can be anything from 1 to 60 minutes but recommended duration is 15, 20 or 30 minutes. You can also set the opacity level of the faded screen and the colors used for displaying the time. It also displays the number of breaks that you haven taken and the health percentage.
In the GUI, there are no options given to make it display an image instead of the colors when the screen is faded. According to the developers, you have to manually change the background to a picture stored on your computer in the settings.xml file. In a similar manner, you can set an audio file that is played when the screen is faded and a reminder is displayed.
You can download FadeTop from http://www.fadetop.com/.