Standing greatly increases your risk of carotid atherosclerosis and varicose veins.
Best is to sit, but NOT for long uninterrupted periods. There was a good article about this a while ago from Cornell University ergonomics researchers: http://ergo.human.cornell.edu/CUESitStand.html
Here was their bottom line recommendation:
Sit to do computer work. Sit using a height-adjustable,
downward titling keyboard tray for the best work posture,
then every 20 minutes stand for 2 minutes AND MOVE. The
absolute time isn’t critical but about every 20-30 minutes
take a posture break and move for a couple of minutes.
Simply standing is insufficient. Movement is important to
get blood circulation through the muscles. Research shows
that you don’t need to do vigorous exercise (e.g. jumping
jacks) to get the benefits, just walking around is sufficient.
So build in a pattern of creating greater movement variety in
the workplace (e.g. walk to a printer, water fountain, stand
for a meeting, take the stairs, walk around the floor, park
a bit further away from the building each day).
Whether you are standing or sitting, as long as you are sedentary, it doesn't make a difference. Both are bad. Sure, sitting can cause you to get varicose veins or carotid atherosclerosis, but standing in one spot all day has it's drawbacks too (http://www.hazards.org/standing/).
Sit for moderate periods of time and then move around for small periods of time during your work day. Also, exercise moderately at least a few times a week. It doesn't have to be go into the gym and push weights around or run on a treadmill for 30 minutes.. Do it at home. A good quick workout that will suffice for moderate exercise, requires little or no equipment and will get the heart working is as follows:
TABATA:
20 seconds of work followed by 10 seconds of rest == 1 set,
8 sets == 1 cycle.
Do each of the following exercises as fast as you can, in GOOD form, for 20 seconds. Then take 10 seconds of rest. Repeat 8 times. Work as hard as you can in good form for each 20 second interval. You should improve on the number of repetitions you do each week.
To track your progress, take the lowest number of reps done in a given cycle (one of the 20 second work periods out of the 8 sets) and write it down. Try to improve that number each week.
Do 1 exercise for each cycle: Pushups, Squats, Crunches, Burpee's (Squat thrust), Jump Rope
For example: Pushups, 1 cycle = 8 sets of 20 seconds or hard work followed by 10 seconds of rest.
Do as many pushups as you can in 20 seconds. Stop completely for 10 seconds, do not hold yourself up during this time. Lay down if you can. Start immediately after the 10 seconds is up and do it again.
I substitute my exercises every now and then. For instance, I may change Jump Rope out with rowing on a row machine or doing 20 second sprints. I will substitute Burpee's for Pullups.
Tabata can be as intense or easy as you allow it to be. It is not only outstanding anaerobic conditioning, but great muscular fitness and endurance as well. The best part is it will only take you 22 minutes (2 minutes of a light warm up is good before starting). I'm willing to bet that anyone can find 22 minutes twice week to help better their health. For the days in between your Tabata days, just do some moderate stuff like a nice 20 minute walk, go kayaking, hiking, biking, whatever...
If you're in a crunch for time, take 8 exercises and do 1 cycle. That's a 4 minute intense workout. Much better than no workout at all.
I do this myself and have seen the benefits. I don't run for exercise but was challenged to see how my mile run time would be. I finished the mile in 5 minutes. Not too shabby for somebody that doesn't run at all and only does anaerobic conditioning such as this, Muay Thai, Mountain biking and kayaking.
The evidence is that sitting down for hours per day is extraordinarily destructive to various aspects of your body, including your metabolism, circulation, oxygen distribution, and that it increases the risk of diabetes (and cancer due to consequence of fat gain from a slower metabolism). I believe (per what I've read on the subject) that it also significantly increases the risk of heart attack and stroke due to a collapse in normal / healthy function of the cardiovascular system.
The data on it is rather common these days, a quick google will turn up several high profile write-ups from sources such as the NY Times.
And if we're just talking logical extrapolation - it makes sense that humans wouldn't benefit from sitting down all day, as it wasn't common to our evolution / how our bodies are designed to work. Caveman Joe didn't sit on his rock for 12 hours typing.
Correct, but the evidence does not indicate that standing for hours a day is any better for overall health than sitting. What I really want is a walk-around desk ... but I'll grant that I might be more likely to move around periodically if I'm already standing.
When I'm standing up I tend to move about more and wander off while I'm thinking about stuff. I definitely get more exercise than when I'm sitting down.
Perhaps, but there are only two possibilities (that I see).
1) Standing is radically more healthy than sitting, or
2) Being upright and walking / moving, is what is radically more healthy than sitting
I think that part of the problem with sitting is the blocking of the circulation system through slightly crimping the arteries in your legs. It strikes me that just standing up alone would relieve a lot of that stress and assist the free flow of blood and oxygen.
So if you want to play it safe, stand up, and move about regularly. If you're standing at your desk, I'd argue it's far more likely you'll move about regularly as you're working on problems throughout the day.
I've read previously that the average American used to walk three to five miles per day a hundred years ago, and that's down to a small fraction of that now.
I'd counter argue that the common negative health effects of sitting down far outweigh the common health effects of varicose veins (from that wiki):
"Most varicose veins are relatively benign, but severe varicosities can lead to major complications, due to the poor circulation through the affected limb."
I think the positive evidence for standing versus sitting is overwhelming to put it lightly.
"This isn't actually a new discovery. In a British study published in 1953, scientists examined two groups of workers: bus drivers and trolley conductors. At first glance, the two occupations appeared to be pretty similar. But while the bus drivers were more likely to sit down for their entire day, the trolley conductors were running up and down the stairs and aisles of the double-decker trolleys. As it turned out, the bus drivers were nearly twice as likely to die of heart disease as the conductors were."
The general warning of "correlation not causation" applies here. The studies show some correlation between sitting for hours and various maladies. However, there are so many factors that determine your susceptibility to the health issues you mention that calling out just one factor (sitting) needs to be viewed with some skepticism.
That said, I do use a standing desk for about half of my working hours because I think it is healthier to not sit all day.
There have been countless studies done at this point, spanning decades, directly linking severe health effects to sitting down. Particularly radical increases in the risk of heart attack and other severe cardiovascular trauma.
How many medical studies do you need? There seems to be a new study out monthly at this point proving the link between sitting down 8 hours per day and radically increased risk of death.
Unless you think the people sitting down all happen to be the ones carrying an inherently heightened risk of heart attack. See the 1953 British study I referenced above as a simple example. Recent modern studies have found the same results: sitting all day effectively doubles your risk of dying from a heart attack.
> The evidence is that sitting down for hours per day is extraordinarily destructive to various aspects of your body
That's a bit of an exaggeration. Each day, hundreds of thousands of people sit at their desk for hours, and it's been going on for decades. If it was that destructive, the developer population would have been decimated by now.
I would expect people who use them take health more seriously in other aspects of their life as well thus increasing their life expectancy anyway...