The recommendation, based on the research findings, is to break every hour with at least one minute of activity. When taking a break, any sort of movement is effective, and it does not have to be strenuous. This can be as simple as getting up every hour and getting water or using the bathroom (which go hand in hand). Instead of emailing a co-worker, get up to talk to them. Implement brisk activity by jogging in place or perform jumping jacks for a minute.
If standing is too strenuous or you want to “work up” to the standing versions, do them seated for one minute. The movement can be small and still be effective. Fidgeting including foot movements, toe tapping, or even finger tapping is an example. Isometric exercises such as contracting your abdominals are also effective and can be done in the seated position.
Lunch breaks are a good time to take a short walk. Get up and walk or jog in place, or even side step. If you have an elevator or escalator, use the stairs instead. If it is several floors, work up to more flights slowly. Park in the outskirts of the parking lot and take a longer walk into work. Besides implementing more bodily motion, you will have less dents and dings on your vehicle.
Check out chapter 9 of my book Health at Your Desk for a desktop reminder to Get up and Get Healthy.