A long time ago I spotted a treadmill desk on
Instructables, and was instantly intrigued. As someone who routinely spends 12+ hours a day on the computer, this seemed like a great way to get off my butt without sacrificing work time.
That first design I saw was essentially just a shelf mounted to a wall for the monitor, with another shelf erected around the treadmill arms to serve as a work surface for the keyboard:
Overall the setup seemed a bit clunky, though, and you had to face the treadmill into a wall, which wouldn't work with the small space we had to work with in our back room.
I talked to John about it, and we agreed that really all we needed was a single shelf to hold a laptop and mouse, since we planned to use this as a supplement to our office desktop, not a replacement. We started researching treadmills, and within two weeks found a nice fold-up model - a bit shorter than most, so it would fit our space - for $250 on Craig's List.
Here it is in our back room:

An eyesore, yes, but worth it.
Here's the worktop:

John's shelf is so seamless that some of our friends thought it actually came with the treadmill. I love how streamlined it is. He designed the shape of the wooden board to fit around the arms, rounded the edges with a router, and then painted the whole thing satin black. The entire process only took him a few hours, and cost $15.
The trick to such a simple design is finding a treadmill with arms that can support a shelf this way. As you can see, John used large U bolts to fit over the arms and support the shelf with wing nuts screwed in from below. It's extremely strong and stable. The wing nuts also make the shelf easy to remove, in case John wants the extra space for running. (Although so far he's been able to run even with it in place.)
John measured me ahead of time to make sure the keyboard would be at the best height for typing, so it's extremely comfortable to use. Typing and mousing are easy, because I walk at a casual stroll. The first day I walked and worked for four hours straight without a second's thought. Then I stepped off and nearly collapsed from jelly knees. Ha! After that I kept it to one-hour increments as I built up my stamina.
Here's another reason the eyesore is worth it:

In addition to working, I can also use the treadmill at night while watching TV with John. Multipurpose ftw!
We've had the treadmill desk now for nearly a year. I don't use it every day, but usually I'm on it no less than 3 or 4 times a week. The days I use it I'll walk for up to two hours, then switch to the sit-down desk for a while, and then go walk again. It's saved me from growing into my desk chair, and is also a great way to wake up from after-lunch drowsies.
So, there you have it! Now, who's off to find a used treadmill?
*****
Come see ALL of my craft projects on one page, right here!