I did an Ironman, its a long day and you need to be physically strong, but it's nothing compared to my biggest days climbing. I never did Raineer in a day, I have done some aid climbing and carrying an aid pack to base of Washington Column in Yos was much harder than Ironman...
At Ironman:
1. people handing you food and water all day
2. if you fall, someone is there to pick you up
3. if it gets too cold or it gets too sketchy, you can bail out ANY time
4. you dont have to carry any gear
5. pizza and chicken soup and a plastic space blanket at finish line
I'd rather be in the mountains...
