You are right about the mood boost. I so miss running. I tore my knees up because i approached like anything else - all in. I started in January 2013 and in October of that year I ran a half marathon in 2:08 and change. I ran for over 2 hours non stop. But this is no brag; it's a lesson in pushing too hard. Both knees were ragged inside - meniscus tears, frayed patellas and aggravated arthritis. I had one scoped and the doc showed me the pictures and told me my running career was pretty much over unless I wanted to put him on retainer. This is also something of an answer to the questions I am asked in the diet thread about practically starving myself. That's just how I roll. When I decide I want to weigh less, I cut back drastically. When I decide I want to be a long distance runner, I run long distances. I pay the piper pretty regularly.