My baby is 1 year. I just started walking him more now with the warmer weather. He is a machine. I am guilty of circling the block a few time extra because he is just not done. I would think he would be tired due to the fact he does a serious "hop" when we first get outside and tries running (at least 10 minutes of this) and then as excited he gets when other people walk by (he loveeees everyone) but he never gets tired. The only time he lays down is when we get to the front door and he does not want to come in. Good thing I am bigger then him