In short, they’re effective at burning more calories as you work, but you’re also in for a rude awakening if you try to actually walk on them for eight straight hours. Whatever you’re doing at your desk, it takes some serious brainpower to get from A to B. You’re using a computer, or you’re reading over and signing documents; your brain is at work. With constant walking, you’re getting an eight-hour cardio workout. While there’s nothing wrong with that (hikers and campers do it all the time), it will be taxing on your body.\r