I have a sit/stand desk at work and home. I tend to stand about 4-6 hours a day, and haven't noticed any difficulty concentrating when doing so. I feel more ale

I have a sit/stand desk at work and home. I tend to stand about 4-6 hours a day, and haven't noticed any difficulty concentrating when doing so. I feel more alert and prefer standing unless I have foot pain. I deal with that by shifting weight balance (by leaning, or putting one foot on a box or up against the wall) and I have a pretty comfy mat to stand on. If it's uncomfortable I'll just switch to sitting for a while. I also walk ~3 miles a day.