When I sit for to long my feet start to go numb I am under the impression that this is poor circulation what can I do to improve it.?

May not be. Although circulatory problems may cause the symptoms you describe, you may also need to consider that sitting for a long time in the same position may be producing a compressive neurovascular problem. That is, sitting may be pressing on blood vessels or directly on nerves that then give you the sensation of numbness. Changing positions, chair, adding a pillow, or getting up often may solve it.
Probably not. Probably it's not a circulation, but more of nerve/s impingement -- so just get up and walk around more -- also walking exercise daily is good for general health and weight management -.
Numb. Probably more likely nerve compression perhaps lower back Numbness is usually not the primary symptom off vascular disease Also vascular disease is usually improved with sitting and worse with activity.