As I've got older I have found that I can still get around a 2 hr run, not that I'm doing that at the moment, or a 4/5hr bike ride without food, although I always drink on the bike.

However, what I have found is that if I do not eat I am much more tired the day(s) after than if I had nibbled on something.

Apart from ripe bananas two of my favourites, which I can digest on the hoof, are cooked Charlotte salad potatoes and hard boiled eggs, both wrapped in a bit of foil which is easier to undo than clingfilm.

They also make a nice change from the sweet stuff.