Try to get up and move away from your desk every 30 minutes and take an active five minute break every hour. You can exercise fairly unobtrusively while remaining at your desk, so you don't even need to leave the room. These two exercises will get your circulation going and stretch your muscles. As an added bonus, you'll get back to work feeling more focused.

At the start of each exercise, breathe in deeply and exhale.

Punch the sky

Use your hole puncher for this exercise. Hold it in your hands, palms up, fingers interlocked and use your thumbs to balance it securely. Sit up tall in your chair (or if possible, stand.) Holding the punch as described, stretch your arms high over your head. Take a deep breath in and on the exhale stretch to one side as if trying to bring your shoulder in to the side of your body. Now return to the upright position and stretch in the opposite direction. Return to the upright position and repeat at least ten times.

The phone book calf stretch

Sit upright in your chair with a phone book or a heavy file on your knees and move to the front of your chair. Your knees should be at a 90 degree angle. Put the balls of your feet on the edge of two piled up telephone directories (4-6 inches high) with toes pointed forwards. Lower your heels as far as possible until you feel a good stretch in calves. Now raise your heels as high as possible. Focus on calves - feel the muscles working. Hold for a count of ten and release. Repeat for at least a minute.