I like to walk and cycle and I walk to work daily, but walk 13 miles!! That would take approx 3 hours at a good pace each way and then a days work in between?? Even to cycle that distance daily in all weathers would get onerous. I used to do 6 miles each way for about 5 years on a bike and after 5 winters I'd had enough. That's even with a decent bike and all the right gear for the weather.