Been reading up on zone 2. Started with a long walk and surprised myself with a 6k, which almost immediately became 10k. Sounds like a lot, but zone 2 is easy to maintain - that's the idea. Start easy, then work on improving pace and purpose. Continued it to the 90 day 'habit forming' range, then found I could now run the 2.4k from school non-stop now (never did this before), then a 6k run after about 3 months of fast, normal (not Olympic style) walking. Holy shit, was I inspired! Now working on a 10km/ hour running target. I encourage anyone trying to improve themselves - hope your journey works out!