Diet

Drinks that replace electrolytes are good, your body needs the salts to keep going.

In terms of bars these taste amazing and I don't think they're too bad for you.

Bananas and fruit in general.

And for me, a stop for a decent coffee always really helps.

I found that gels are great, but best saved until you need that pick me up... I did a sportive 100 a while back and bonked at about 70 miles, like literally could barely carry on. Had a gel and about a litre of water and a few miles later was back in, and was racing the last few miles.

The morning of a big ride I'll happily go to town on the protein say loads of eggs (and maybe some bacon...) with a handful of brown toast, some fruit and lots of water and fruit juice. An old friend told me before any ride you should drink till your pee is clear, and I still stick by that. Starting off a ride dehydrated makes you feel dreadful. Much better to drink too much and have to stop to pee than downing all your fluids quickly once out and getting a stitch/running out of fluid.

Before a short ride, if you do get some protein powder, shake it up with a portion of oats. It's a bit love it or hate it but a quick and easy way to get your protein and carbohydrate supply.

I think everyone has a different distance that beyond which they need fuel to continue, I can ride 25-30 miles without needing to eat and just with water, but past that I fade fast. If I eat half a cereal bar every 10-15 miles or so, with the odd banana then I can keep on indefinitely. Sometimes it's good to have some proper food in the middle too, the more simple carbs the better.

One last thing, have a big meal the night before and try to get plenty of complex carbs, you'll get an energy hangover (don't know what the actual term for this is.)