Good Posture
To exercise while sitting at a Computer one needs to sit properly in a chair designed for desk work. Keep the back straight while the level of the computer monitor top is the same level as ones eyes. Wrists should not lie on the keyboard or mouse to prevent carpal tunnel syndrome. Legs should be bent at the knees, so that the knees are just a little higher than the hips. Let the feet be flat on the floor. Every half hour one needs to stand and stretch or walk around a bit. The calves should be stretched and eyes given a break from focusing too much on the computer screen. Stretching the calves prevents blood clots from developing in the legs.
Some helpful exercises
It is important to learn to stretch the neck, flexing the head forward and backward, side to side and looking right and left. Rolling the head around is wrong as it may damage the joints of the neck. Rolling the wrist regularly prevents carpal tunnel syndrome because of too much typing. Rolling the ankles improves blood circulation to prevent the tingling feeling called pins and needles. Many people hunch in front of the computer keyboard. To counter this posture one can open the hands wide, rotating the wrists externally followed by pulling the shoulders back. This produces a good feeling as the stretch is across the upper chest. Abdominal muscles should be contracted and held that way for several seconds before release. This practice needs to be repeated many times during the day while sitting in front of the computer. To avoid feeling stiff, the arms, neck, legs and torso should be stretched regularly while seated.
When the computer requires rebooting, or when one is downloading large files this creates an opportune time to do ambitious exercises like sit-ups, push-ups, and jumping jacks depending on your location. Hand grippers are good to be with as they are small and light. When reading text on the screen or on paper the hands are free and this is the best time to squeeze on the gripper as this is a good forearm workout. Taking several deep breathes of fresh air refreshes the whole body. A large stability ball kind of desk chair enables one to sit with the back straight and the abs firm. While watching videos or talking on the phone one can bounce and be doing basic toning exercises. The actual ball form needs to be used in moderation during typing to avoid tendonitis.