I have read about this but wondering if people in the more advanced age group have experience with this.
i am 67 and have been riding every other day for the last 8 weeks. I usually do 15-20 miles on weekdays and 30-35 on weekends. After the long rides I feel well and may clean bike, take shower, eat lunch.....but 1-1.5 hrs after the ride I get very significant fatigue. I must lay down and sleep for 2-3 hours. Don’t want to move.....all I want to do is lay down.. Once I am up I feel fine. It does not happen on shorter rides.

Is use one Gu at beginning of ride and one at mid ride. Will drink 2 full bottles of G-Zero ( maybe I should use regular Gatorade).
Should I try snack bar mid ride? What would be good to eat after the ride? Anyone experience the same thing?