Are there any medical studies to show and measure the value of a standing desk? I realize that sitting for 10 hours a day is disastrous to a person's health, bu

Are there any medical studies to show and measure the value of a standing desk? I realize that sitting for 10 hours a day is disastrous to a person's health, but how much benefit does a standing desk provide when compared to getting up and talking a walk every hour or so? Also are there any unintended consequences of standing all day as opposed to sitting all day (varicose veins?)