I subscribe to the Economist, keep the current copy in my laptop bag and read it when travelling for work. I find it serves as a useful proxy for how much of my life I spend travelling on business.
Normally, I find that my "Economist Stress" is a weekly occurrence... I get to Thursday evening and I haven't finished it. This is a good sign: it means I haven't spent too much time travelling.
This week, thanks to multiple trips to Bedfont and Hursley, I completed reading it this morning. No wonder I'm tired!