Some years ago, I somewhere got a little booklet describing Chinese "swing exercises." These were simple movements swinging your arms that were supposed to get your circulation going. People pointed out that orchestra conductors, who swing their arms vigorously, tend to be long-lived.
Then I forgot about the booklet, and now I don't know where it is. But when I read some articles suggesting that strenuous exercise like working out at a gym or running 5 miles a day may not be as important for health as not being totally sedentary for hours and hours, as pointed out by colleague David Mendosa, I thought of those exercises.
I have a feeling that the reason sitting for hours and hours, as computer programmers do, might be bad because doing so slows down your circulation. Think of your bloodstream as a garbage-disposal system. When it's moving fast, it's picking up metabolic "garbage" and carbon dioxide and bringing fresh food and oxygen to your cells. If it's stagnant, that garbage will hang around longer, with the potential to cause harm.
When your circulation slows down, some of the small capillaries actually close off. More stagnation. And poor circulation, especially closed capillaries, means fewer active sites where glucose can be removed from blood and fewer active capillaries to send insulin to cells that need it.
So just getting your circulation going by swinging your arms should be beneficial. A site describing how to do this with type 2 diabetes is here, and a site with a lot of links is here. There are a zillion more on the Internet.
One thing about this type of exercise is that it can be done by almost anyone who isn't paralyzed or bed-ridden or very arthritic. You could be 90 years old and confined to a wheelchair and still swing your arms.
I think offices should have hourly breaks in which people do simple exercises like this. If you're retired, set an alarm to go off hourly to remind you to swing your arms. I think that rather than swinging your arms for 30 minutes as in the first article above, it would be better to swing your arms for 3 minutes every hour, thus getting about the same total exercise but spreading it out to avoid being too quiet for too long. If possible, you could put on your favorite music and "conduct" it as you swung.
Arm swinging takes no equipment or gym membership or special jogging attire. And who knows, it may be just as beneficial.