Set a timer today for my walking/running, to push myself, set it to 1 minute running / 2 minutes walking, then I set that to a loop, it really kicked my ass. First couple runs were easy enough, but it quickly caught up to me, I even took a break half way but still felt drained, by the end I was only managing a few shuffling steps for the running sections before being completely winded. Just goes to show how much I've been leaving in the tank previously by winging it and running whenever I felt like it. My feet are killing me right now, but overall it feels good, like I made progress.