So club advertise 12-14 then haul you round at 16? Abysmal. I lead my own group of friends on a small weekly ride and plan at 24kmh. I do Ironmans so no stranger to miles, but doing two hours at a significantly faster pace of say 28kmh would cripple me
My friend, who also cycles with the club said it was a bit naughty of them, going as fast as the next group up. I just find it odd that I can go round with them and not feel any detrimental effects on the ride itself, but the fatigue comes on a couple of hours later. That is what I don't get, what brings it on later after I have had a drink and eaten lunch? The only thing I can think of is that I am not eating enough, I did have the same sort of lunch as I would normally have on the weekend, and it may not be enough after three hours of moderate exercise, as opposed to just cycling into town, doing shopping then coming home again. I'll try shoving more (decent) food down next time and see if that makes a difference. Next time they should be back to their normal speed so it (hopefully) may not happen again.
I don't think hydration was the issue. At the halfway point on the ride when we stopped for a snack, I needed to empty my bladder (behind a tree), which I would think means I am adequately hydrated.