Very useful info for me (over 60 and slowing.. ;-)

I can see that these exercises as very useful for 'office workers' (and) who sit long hours to avoid that dread 'deep vien thrombosis (การเกิดลิ่มเลือดที่ทำให้เส้นเลือดอุดตันได้).

I however suggest that, "if" we can, we should do more strenuous (resistive) exercices for 30++ minutes "everyday" and not sit for more than 1 hour each time (we sit down) -- that include 'in front of a computer like now too' ;-).