“S” says: I have been trying to convince them about the importance of second breakfast. 
I saw it in the Hobbit – Pippin was my ultimate hero until I discovered G. And both of them believe in frequent nutrition.
If Sid and Doris are aiming to do around 6 hours of cycling per day they should definitely be planning to have second breakfast and first lunch. Personally I would add elevenses to give a balanced regime of nutrition every 90 minutes.