No one believes me when I tell them the worst part of the Whitney Trail are the switchbacks down lower at the Portal on the return trip. People make such a big deal about the 97/99 Switchbacks but the ones in the forest are murder coming back down.
I used to feel that way too but over the years that actually has been the least painful part for me. By then I'm breathing air with more oxygen in it and my feet don't seem to hurt like before at that point. It's also the best part of the trail for walking downhill. Anyway probably an indication though of how crappy I feel on the rest of the hike more than anything else.