The connection between diet and athletic performance was never intuitive for me. When I was in my 20s I took several bicycle trips down the 180 mile C&O towpath. On my first two trips, I packed raisins, carrots, pita bread, and parmesan cheese, because it would not spoil in the heat. Fit as I was, I still suffered terrible leg cramps and fatigue. Later, and even through my sixties, I made the same bike trips (camping all the way) but I learned to pack better meals, mostly freeze dried food and powdered Gatorade. there were no cramps and I had a pleasant, easy +180 mile five day ride.
Yep, I was young and didn’t realize carbs are great for quick energy, but heavy exertion day after day requires protein for muscle repair. I’d start to wig out about 3 days in and couldn’t figure out why. Roller coaster ride for blood sugar, most likely. I haven’t cut carbs out, they taste way too good, but the portions are considerably less. I shed 80 pounds in 2019 and have kept it off. Definitely pay attention to what I consume now, and have never felt better.