With 2 older kids who are also quite active, the babies have no choice but to be on the go a lot!
They spend a lot of time riding around in the car, thankfully they have no complaints about car rides.
The other large chunk of time is spent in their stroller at various sporting events. Many times they want out to explore, but I try to arrange snack times for during stroller time. They are content to be in the stroller if they are eating, if the stroller is moving, or if they are just so tired.
Recently at a soccer game we didn't even realize Little Guy had started to doze, we just thought he was content up there. Then we saw his head bobbing. Pretty soon he bobbed forward enough that his head just rested on the front tray.