The sign that says 1.9 miles to the summit has been discussed in the past. I believe that the conclusion was it is short. I forget the actual distance, maybe 2.5 miles?
We dayhiked Whitney 5 times with this preparation. YMMV.
1. Living in SoCal, we hiked Mt. Baldy (10,064') many times.
2. About a week before the hike, start taking the herbal supplement gingko biloba available in any grocery or drug store.
3. Begin the hike well hydrated
4. Take several aspirin (not Tylenol, Advil, or Aleve) at the start
5. Drink water on a schedule. If you wait until you are thirsty, you are already dehydrated. It is easy to replenish water along the trail all the way to Trail Camp.
6. You need calories. Take high carb foods and sport drinks. Avoid the harder to digest proteins.
7. Rest periodically. It is a marathon not a sprint.
