In my teens I was in great shape, raced BMX, road biked, ran, karate etc. Between 30 and 50 I got soft put on an extra 40 lbs etc. Two years ago I turned it all around, lost the weight, hit the gym, and cycling has ended up being my exercise of choice weather permiting. Most rides are about 25 miles at my max warp couple times a week. I usally get two spin classes and weight training in a typical week as well. I am in good shape for a 1958 model. Have been a couple group rides in the 35 mile range with rests and food breaks no worries. So tried a 50 mile ride, no breaks at what I figured was a pace that would just about drain me by the finish. 30 miles no problem but at 40 I hit the wall I had never experienced it. I ate a couple energy bars, drank the rest of the single water bottle and finshed the ride with out too much trouble a bit under 3 hours. Once home I was a zombie, no energy, couldnt think right just felt like crap. I ate carbs and protein, drank lots of water and ending up going to bed till the next morning. Took another whole day to feel normal again. Of course I knew I should have raised my miles a bit at a time ,drank and more ate earlier but I guess I need to get beat up to learn. I have concluded that I am in great shape for about an hour. Bright side is I now have another goal..true endurance.

From another 1958 model, I found I need to hydrate waaaay more than I thought - two water bottles and a stop someplace to top off if possible on a 45 miler. I do the energy gel things at least every 45 minutes, and make sure I have really hydrated and carbed up before I hit the road. Two weeks ago I wiped myself out similar to what you describe at 45 miles on a 47 miler - almost had to crawl the last two miles. Yesterday did a harder 64 miler - but lots of Gatorade, food, etc. I planned a stop at one store to make sure I could refill the bottles and drink a third bottle of gatorade, and that set me up for the final 40 miles or so of the trip. I also found that now I am able to put in the miles, I think I will benefit more from shorter (30-40) rides with hills, or intervals, or whatever, instead of trying to push hard for long distances. At least that's what this noob from 2011 has discovered for himself, for now - I expect it all to change...

40 miles on less than a bottle of water? Mystery solved.

You need to eat before you are hungry and drink before you are thirsty in order to keep your body fueled. Running your nutritional stores down to zero before you refuel will not make your body happy.

I've only hit the wall once and that was enough. I make sure to eat and drink at regular intervals when I ride now.

+100 Drink up I use more than that in the winter time, and it's summer still in most of the country.

+1

30 miles last saturday and cool enough to require long sleeves- two bottles and a coffee on the ride. Food was not an issue till home then I emptied the Fridge of Bacon for sarnies- and a chocolate bar- then a taster of Cheese and cold meat -and then another chocolate bar.

When you start doing three hour rides you are into endurance mode, even if it seems easy.

Carbs, electrolytes, and fluids before and during is probably the answer. Energy gels really do work to get you home.

I've learned that I will be toast unless I drink and eat before a ride, during a ride and after a ride. The old maxim "Eat before you're hungry, drink before you're thirsty" works for me.

Yeah, a little OT, but when I think of humble pie... https://www.youtube.com/watch?v=ylviT4C0cmQ

Brad

I try to drink from my water bottle every 5 miles (50/50 mixture Gatorade and H20) then gel or Clif bar every 15 miles. I also make sure I'm able to refill my water bottle somewhere about 15 miles into the ride or 30 miles if I carry two water bottles.

That's what came into my mind when I saw the thread title, but I was thinking "77th and Sunset".

Bonking is part of the learning curve. Plenty of good advice so far. I'm a slow learner and must have bonked 4 or 5 times over the years.