I have done a 2x 40 minutes train commute for the last year, before I started I bought a Kindle and read a lot of books. I have found it to be very productive,

I have done a 2x 40 minutes train commute for the last year, before I started I bought a Kindle and read a lot of books. I have found it to be very productive, if you are really motivated you can read books which are related to your job. So when you arrive at work you are ready to apply some new things you learnt. Otherwise I sometimes catch some sleep if I am tired.