I quit running...

...but I didn't decide it.
I always write down on excel sheets all the possible datas on my workouts. What I do, for how long, how far, how many reps... everything. It may sound excessive but on the long run it works, as it allows to keep track of the improvements but also of the changes in my training habits. I highly recommend to everyone into fitness to write things down.
Anyway, having a look at this year's sheet I noticed that I don't run anymore. I mean, I've never been a big runner but I used to go out running for 45-50 minutes at least once a week. Since the day I got my footbike, kicking and fast-walking replaced it totally.
I still do some running during my mixed cardio sessions, this means that I alternate running around my house (mostly hill-sprinting) and hitting the heavybag in my garage. Running in this case is limited to 3 or 4 sessions of few minutes but it's quite intense as it's mostly uphill.
I have to say that my knees and my back are doing way better since I quit long runs. I could imagine that running was bad for the knees but I didn't realize that it was so traumatic for the lower back too. If I knew it, I'd quit before.
Once again I find myself advocating footbiking as a substitute of running (not as a substitute of cycling): it's way better for your health.
If you don't want to buy a footbike, then consider fast walking, the cardio workout is quite the same and you can do it also with a regular pair of sneakers.