I've been standing here all day.

No, really. I'm testing standing desks (or "height-adjustable desks"), and I'm not 100% sure I'm using them correctly. I've heard you're supposed to stand for a set period, maybe use them an hour at a time, then sit to take a break. I'm "breaking" that habit. For my health, for a change of perspective, and for a wild experiment, I decided to test two different models this summer and see what happens when I stand up.

First off, you should know about some reason scientific stats. There's a new science advisory that pretty much tells you to stop sitting all day...or else. There's an increased risk of heart disease. My grandfather, whom I have never met, died from a heart attack due to some complications with heart disease. I've been told I have his exact same build. It's not something I want to mess around with, so I've been biking like crazy this summer and standing at my desk.

Another study found you can make some radical productivity improvements if you stand and avoid sitting. To see how it all helps, I tested two radically different models (both of them proved to be excellent options) and one brand new stool.

You really gotta move. That's the short summary of what is happening in workplace ergonomics trends, and this particular desk is the best way to do that right now.

There were a few things I liked about it. The treadmill itself stayed firmly planted on the floor and the rubber tread meant I didn't slide around at all. The desk is sturdy enough to never rock back and forth, which is a problem I've had with other models.

LifeSpan gives you some digital controls for raising and lowering the desk easily, but it's even more innovative than that. There's an app I used to track my step count all day; it connects to the desk over Bluetooth. Tracking is an incredibly important feature because it uses the concept of gamification--we want to beat our best score--and applies it to workplace ergonomics. During my test, I tracked my steps like crazy and actually wanted to walk for periods of the day and even bump up the speed a little. (Note that LifeSpan says you should take breaks and not walk all day.)

There's a large armrest right in front of you that helps you keep your elbows raised and avoid getting too stiff when you walk. The TR1200-DT7 desk is also not priced out of this world--it compares with several models from Steelcase and Teknion I've tested in the past. One word of caution, though. It takes time to adjust to the treadmill, and LifeSpan readily admits that. For me, I used one for a few weeks before I felt comfortable typing up entire documents while walking.

You can skip the treadmill altogether but still gain many of the health benefits of a height-adjustable desk. One of my favorite models is the new Varidesk Pro Desk 60. I'll be brutally honest here: I'm a bit of a cheapskate. I really like the lower price of the Pro, which is well under the $1,000-or-more price-point of many standing desks. Yet, it is stable, lifts up quickly from a sitting position, and looks trendy. During my test, I lifted the desk up for all day use. The next day, I lowered it to sit and missed the feeling of moving around and pumping up my energy level.

My big piece of advice here: Go with the 60-inch size for a standing desk, not the more common "compact" size. A smaller desk means you don't have as much room for your gear, but it's even more critical when you're standing. Remember, the idea is to move. That means you might decided to sway side to side, do a leg pull-up, or even try standing on the FluidStance Level balance board. When you do, you need more space. I kept my laptop on a stand off to the side, used a huge Philips monitor, and felt like I needed all of the space when I went "mobile" right at my desk.

Last but not least, I relied heavily on the new Mirra 2 stool, which is one of my all-time favorites for comfy desk seating. I highly recommend this ergonomic chair if you decide to stand up and stop sitting all day. What it means is that you can take a quick break for an hour to sit without lowering the desk. The "up high" view (think: a king or queen on a throne) gives you a new perspective on work, which I loved.

The Mirra 2 has knobs and levers to get the perfect sitting position. I tended to keep a firm lumbar support for my back and left the arms in a lowered position and twisted back out of the way. As with most Herman Miller products, it's great because you can find the right position for your body type. Other chairs tend to offer as many knobs and levers but not as many positions for your body type.

Overall, these products are game-changers. They radically improved my fitness at work to the point where I don't plan to go bck to sitting anytime soon.