When I was 40 my daughter was not even born and 14 years later I still have my share of 16 hours per day when my projects are at a peak, this is not a privilege of travelling young consultants, it just a matter how much you identify yourself with your work and if you enjoy what you do. Why do you think 40 is the end, I was close to 40 when the my SAP journey started, there was not even a thought that there was nothing beyond 40 or that my life had to change drastically.
I was on management training last week, my company is still investing in me. I don't feel old and I have my plans to increase travelling instead of reducing it.