The John Muir Trail can be hiked from north to south (Yosemite to Mt. Whitney), or from south to north (Whitney to Yosemite). Most people do it north to south, as we did, for one very good reason: The elevation profile.
As you can see from the graph, the trail starts at 4000 feet elevation in the north (left side) at Yosemite. Although you rise to almost 10,000 feet in a couple of days, you soon come back down below 9000 feet. There are lots of ups and downs, but the general trend as you move south is higher and higher. This gives you a chance to acclimate as you go.
If you start in the south, within the first couple of days you have to climb to the top of Whitney at 14,508 feet. We met many people who had climbed (or tried to climb) Whitney without the acclimatization that we had gone through, and they were having a terrible time. For us it was no big deal, as we had already climbed over four 12,000′ passes and one 13,000′ pass, and had been sleeping between 11,000′ and 12,000′ most nights.
The other negative about going south to north is that you have to pick up a WAG bag before you start and carry it with you until you get to a waste disposal location, perhaps 10 days away. No thanks!
So what are the effects that you feel while getting acclimated? Do you always feel a little short of breath or does it eventually get to the point where it feels normal?
Comment by Don — August 15, 2013 @ 7:45 am
If you’re lucky it just means easily out of breath. Having to stop frequently and take deep breaths. But many people suffer from altitude sickness, causing nausea and headache. Sometimes people die if their bodies can’t cope with the reduced oxygen.
Castaway/Dale had similar problems on earlier trips to the Sierra, but this time his body was prepared and he did fine.
If you work up to it slowly your body adjusts, I think by producing more red blood cells to carry the reduced oxygen more efficiently, though I can’t back that up. Whatever the cause, you still have to breathe harder but there are no other symptoms.
Comment by Daryl — August 15, 2013 @ 9:27 am
I’m glad all of you acclimated and didn’t experience any altitude sickness this time.
Comment by Donna — August 15, 2013 @ 1:57 pm