Just bought a standing desk. I really like it. It isn't as comfortable (obviously), and my legs, feet and back are sore by the end of the day. But they're sore in a good, used way and fine by the next morning.
It definitely feels healthier then the sore back and thighs I'd get from sitting still all day.
If standing desks ever take off, I wonder if we'll eventually face news articles with titles like: "Standing for hours can shave years off life"...
Very, very unlikely.
The whole "exercise good, sitting kills you" thing was first noticed in England among bus drivers in 1953. There the driver and conductor were from similar socio-economic backgrounds, similar pay, etc, but one sat all day, and the other stood. Drivers died much faster than conductors. Every significant followup since has confirmed the basic conclusion. Sitting all day is not healthy for us.
Thanks for the link. The conclusion actually indicates standing is not sufficient, exercise is necessary.
From Wikipedia, "[...] sedentary drivers of London's double-decker buses had higher rates of cardiovascular disease than the conductors who climbed the stairs" and "[Jerry Morris] performed further studies that showed slow movements such as gardening helped very little and exercise had to be more vigorous to help."
I've tried both extensively and the conclusion I've reached is that staying in one position, standing or sitting, for many hours is the real culprit. The only real cure to sedentariness (which is probably what really shaves off lifespan) is to be as mobile as possible.
In Denmark they are everywhere. I've been consulting/freelancing for a number of years and only on very rare occasions have I not had an adjustable desk. I haven't yet heard about negative conseuences.
Fortunately with a desk that goes up and down that is an easy one to fix ... someone just needs to do a study of the ideal proportion time and frequency for changing between sitting and standing.
I am fortunate to have a desk that has adjustable legs, so I was able to try out with a standing desk. I have been doing this for about two weeks now and my verdict thus far is the same as yours.
The first week was a bit brutal and my heels were really sore at the end of the day, but luckily my dad does ergonomic consulting and had an anti-fatigue mat lying around, now I can stand 8+ hours a day and not feel any pain or soreness. I get to walk around more and I feel a lot more productive than when I was sitting. Oh, also I am burning about 1300+ calories for standing each work day, which is about an hour of intense cardio.
If you have been on the fringe about working standing up, I say do it. Just make sure you get an anti-fatigue mat because that will take a lot of pressure off your feet.
From my experience, it's probably your shoes. I've been using a standing desk for about a year and can definitely notice a difference in my feet dy to day depending on the shoes I'm wearing (personally, I find five fingers the most comfortable for me, but I think that's because I move around the most while wearing them). I did notice that adding a mat (currently it's just some really thick shelf lining, although I've thought about getting one of the restaurant style floor mats) made all shoes feel better. The shelf liner costs ~$5 so it's worth giving it a shot. Mixing in some sitting breaks as well (~30 minutes a few times a day) can also make a big difference since it gives your feet some time to rest.
2) a brick. A brick sculptor friend of mine was advised by a worker at the brick plant to keep one foot on a brick to rest it, alternating as needed. Says she's never had another day of back or foot pain.
I've used this larger (3' x 5') one for over a year, usually with shoes but more recently in socks, and it's been great. It looks like the one in first picture but gray and only slightly glossy. Recommended.
It definitely feels healthier then the sore back and thighs I'd get from sitting still all day.