I’ve just started again this year, well 2 weeks ago, my commute is 16.5 miles each way. This is my 4th year and I’ve started adding extra days, I used to ride in on just tuesday and thursday, last week I did tues\weds\thurs and have to say really felt it on the last ride home.
I think the main point up above is related to the speed, I have this horrible tendency to treat each ride as time trail and really need to take it steadier on some of the rides. I’m planning on adding mondays as well, but this is also the day I ride at night so we’ll see how that goes.
Oh, I ride a flat barred road bike with spds. I have a porridge breakfast (usually) and on the bike I have a protein shake with milk. I buy bananas for mid morning and just before leaving, lunch is quite often a baked potato, and I have a protein shake when I get in.