I really had a problem with "crashing" doing 50s early this year. I actually did an article for our region's endurance newsletter and asked many people for input and did a ton of research. I then changed what I ate/drank and made a complete turnaround about how I feel during and after a ride. Here is what I do:
I drink TONS of water the day before a ride and before I go to bed. (You want your horse to do the same, right?) I then get up and drink a BIG glass of water with breakfast.
During the
ride I eat grapes (great frozen on hot days), cantalope, watermelon and foods that are easily digestable energy = plain bagels, peanut butter, bananas, chicken breast, apples, you get the picture. Nothing processed like energy bars or processed food. If the food isn't simple and ingredients something I know of, I don't eat it. No electrolyte drinks during the ride until near the end after I have drank TONS of water all day (1-2 bottles per loop minimum). If you drink a lot of electrolyte drinks all day instead of water, you may end up more dehydrated and sick.
If your pee is dark, you know you are not hydrated. If you are not hydrated, even on cool weather rides, you will feel bad. Dry mouth, headache, barely peeing, dizziness are all signs of dehydration. If you are not hydrated, you won't feel good about anything you are eating. And if you are eating well, you NEED to
be hydrated to digest it all. If you find it hard to drink a lot, try foods that are high in water content like grapes, oranges, etc.
Some people do just fine on Gatoraide and power bars but they just make me puke and get sick. So if you have a problem like mine, you may want to try this kind of eating/drinking. It saved me this year.