[pct-l] Acclimation to altitude

[Gary Wright]

On Jan 18, 2011, at 9:44 AM, Brandon McGinnity wrote:
> Does anyone have any tips on helping one's body
> adapt to the higher elevations?

Disclaimer: I'm not an expert. The information below about altitude sickness is via a Wilderness First Responder course and the publication "Wilderness First Responder" by Buck Tilton.

Tilton says "complications seldom occur below 8,000 feet" so you should pay careful attention to your body and your symptoms when you cross that mark (San Jacinto, Baden Powell, briefly before Kennedy Meadows, and High Sierra). The day I hiked around San Jacinto Peak I was puzzled about how much more effort it was taking until I remembered that I had crossed the 8000' mark for the first time in the hike.  I had the same experience again the day out of Kennedy Meadows as I crossed 10000' for the first time and of course on Mt. Whitney. After that, the high passes were always extra work but not as bad as while I was first acclimating to the elevation.

The standard recommendation is to 'climb-high, sleep-low'. You acclimatize by sleeping and climbing at progressively higher altitudes but always sleeping lower than you climb. The usual advise is to add no more than 1000' to 2000' feet to your sleeping elevation every day.

Staying hydrated is important.  Avoid respiratory depressants (e.g. sleeping bills and alcohol).

Gaining altitude is a bad idea if you have symptoms of altitude sickness.   From Tilton's book regarding treatment of altitude sickness:

> Because you can't predict who will deteriorate from mild to severe altitude sickness, you must stop the patient from ascending until the symptoms resolve.  It is at this point the majority of life-threatening mistakes are made.  The important rule is don't ascend until the symptoms descend.

Everyone should read up on the details of AMS (Acute Mountain Sickness), HACE (High Altitude Cerebral Edema), and HAPE (High Altitude Pulmonary Edema).  In addition to weakness, lethargy and headaches, the following symptoms are associated with these conditions:
	
	vomiting (AMS, HACE)
	ataxia (loss of muscular control and balance) (HACE)
	altered mental status (HACE)

HAPE symptoms include:
	dry cough leading to productive cough
	shortness of breath (even while resting)
	crackling and/or gurgling breath sounds
	increased heart and respiratory rate
	chest pain

Generally you can sleep below 10,000' feet through the High Sierra between passes.  The trickiest area for this is probably between Death Canyon Creek (8958') to Vidette Meadows (9517').  This is a 60 mile section where the trail generally stays above 10,000 feet.

This also seems to be the area where thru-hikers are most often afflicted with altitude sickness (my own anecdotal evidence on the trail and reading journals for the last seven years or so).  To make things worse it is also an area where it can be difficult to get to 'civilization' without gaining altitude.  Most egress trails from this area cross over 10,000:

	Saddle Near Olancha: 10,557
	Trail Pass: 10,497
	Trail Crest: 13,600
	Forester Pass: 13,117
	Kearsarge Pass: 10,751

The Bubbs Creek Trail continues down in elevation to trailheads in Kings Canyon National Park (5000') and it is probably a good idea to go that way if you've made it over Forester rather than trying to gain altitude again to go over Kearsarge.  Between Trail Pass and Forester there are several trails that head west and drop in elevation as they head towards the Kern River (9000' and lower).  If you are near Trail Pass/Cottonwood pass you can bail out at Horseshoe Meadows (10000' and lower as you follow the road)'

Sleep as low as possible while acclimating, be familiar with the symptoms described above and understand how you can lose elevation as quickly as possible if the symptoms occur (i.e. have a map and know how to read it!).

Radar