I'm old and slow so I'm planning on 8 nights (9 counting the trail head night) to make it to Mt. Whitney and back. This is my third attempt. 2 yrs ago the first blizzard of the year stopped us at Whitney Portal with blowing snow on the ground at the store and two on-going SARs going on during the same time we were to began our hike. Last year I went with a group for an overnight attempt but made the mistake of trying to keep up with those young whippersnappers <G>. I only made it to just below Trail Crest when altitude sickness was too much so I headed back down. Physically, I was fine - not a sore muscle the next day. Hiking is my retirement hobby.
This year I'm going solo at my own rate, spending much more time to acclimate, got drugs to help from doctor, know to force myself to eat and drink and mostly will take my time and enjoy the back country. Make it or not, I plan to take lots of photos and have a good time.
Perhaps I'll see you on the trials. I'm the old fat guy with a floppy hat. <G>