I have such a complicated relationship with running. In many ways I hate doing it, it can be uncomfortable, and sore. It can be pretty boring too. However it keeps calling me back.
It's not as though I feel running changes my body in the way that strength training does, so it isn't the physical rewards that motivate me to get my trainers back on. It's much more of an internal itch (ooh er!). Somehow my mind likes it, and even begins to crave it.
It's a little period of time which is just about me, being outside. Running is hard mentally, and sticking to it, and breaking through can, for a brief moment, feel rewarding. There is something about running in the sunshine that pleases my soul. And we need to do things that please our soul.
The first 3 minutes or so are always the worst. But remember, keeping going means getting to that sweet spot, where your body has given in to the uncomfortableness of cardio work. You find a weird zone, where one foot after another, one foot after another, you manage to just keep going. That's all running is; learning to just keep going.