Originally Posted by FreddyV

You will find yourself pretty tired at first, but you'll be fine. You'll get used to it.

I ride 30 miles a day (2x15) and am still tired after each ride. I'm fine when I take a bit of rest afterwards though. If 2x10 is too much to start out with, take it easy and don't do that 5 times a week, but start with 3. I did and I have only recently been able to ride 5 days a week, and am cycling since over a year now.