No, Rottweilers are not lazy. This working breed was originally developed to walk next to their owner while pulling heavy carts of meat to market, and, when not doing that, to guard the home. So they weren’t really required to run round most of the day or burn off a lot of energy like hunting or herding dogs.
That explains why, in between happily joining you on hikes, and playing energetic games, they’ll be content to lie around the house and relax until it’s time to go again. When you’re ready, they’ll be set off by your side and keep going for as long as you want.
If you’re looking for a dog that prefers a gentle stroll or a hike in the hills instead of a high energy run, a Rottweiler could make a great companion for you.