Thirsting for Adventure (Trekking in Peru: Day 2)

Thirsting for Adventure (Trekking in Peru: Day 2)

“How much water will you need for the day?” the guide asked as we prepared for our second day of trekking through the Andes.

“I don’t know, a liter?” answered one of our group members. I gave the guide a skeptical look, that number seemed dangerously low to me. Our plan for the day included ~4700ft of elevation gain through an exposed section of high altitude desert with no shade and the forecast was predicting temperatures over 90°F. Both my experience and the research I’ve done on water requirements for hikers suggested that 1L wouldn’t be anywhere near enough:

“When’s the next time we can get water?” I asked, hoping I was missing something since the guide seemed unconcerned. “We can get water when we stop at Maranpata for lunch,” he replied. I looked at the elevation/mileage cheat-sheet that I’d made up before the trip. Maranpata wasn’t that far away, but we had to climb from the Apurimac River at 5084ft (1550m) up to 9950 ft (3033m) to get there.

“Hmmm,” I paused to to do some calculations. The guide estimated it would take us ~6hrs, it was going to be a strenuous climb, and it was going to be extremely hot.  I would probably need ~4L in that time, but I could ‘camel-up’ and drink a liter with breakfast and drop that number a bit. “I’ll take 3 liters,” I concluded.

“Really? Are you sure you?” replied the guide, urging me to take less.

“Yes, I’m sure,” I replied confidently. I’d made the mistake of skimping on water during a heat wave on my AT thru-hike in Virginia and ended up suffering from heat exhaustion (complete with nausea, vomiting, and double vision). It wasn’t an experience that I cared to repeat.

The guide remained unconvinced, “Water is very heavy. Make sure you don’t take more than you need.”

“I know,” I replied.  “A lot of people skimp on water because water is heavy and they want to keep their pack weight low, but when temperatures climb over 90°F skimping on water isn’t just a bad idea, it’s dangerous! Even though its heavy, for conditions like these most hikers I know would carry 2-3 L of water.” Eventually everyone sorted out how much water they were going to carry (the range was 1.5L to 3L) and we set off on our adventure.

The trail rose steeply out of the canyon, providing us with some shade as we started our first uphill climb of the trek. Since the temperatures were already in the ’80s, we would enjoy the shade while it lasted!

The first couple of switchbacks leading up from the river seemed long and gentle, especially since our guide was leading us with a slow deliberate pace called rest-stepping (a strategy I was familiar with from high-altitude mountaineering). Down by the river at ~5000ft rest-stepping felt awkward and out of place, but as we gained elevation and the switchbacks got steeper it began to feel more natural for me.

Unsurprisingly, the distance between the fastest members of our group (me, Jari, and the guide) and the slowest people in our group began to grow as we climbed. We also lost the glorious shade, and began to split our time between hiking in the blistering heat of the sun and baking in the middle of the trail while waiting for the group to catch up.

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After three hours of hiking we’d traversed 1.2 miles and reached Santa Rosa, a small oasis at 6873 ft (2095m) with shade, benches, toilets, and a stand selling beverages and snacks. We took a 10-minute break there and bought beverages. I bought a blue Gatorade, someone else bought a coke, and the Quechuean woman running the stand brought out a pitcher of mud-colored liquid and poured some into glasses for both the cook and the guide.

“¿Qué es esto? (What’s that?)” I asked, my curiosity piqued by the milky-brown liquid. “Acca,” replied the woman. “Chicha,” clarified the cook. I furrowed my brow as I tried, and failed, to translate chicha from Spanish into English. “Inca Whiskey,” elaborated the guide smiling broadly. I wasn’t sure if he was kidding, but it seemed plausible that it was some sort of home brew. The only way to know for sure would be to try some. Even though I like whiskey, alcohol seemed like a bad idea on a scorching hot day when I was headed to altitude, so I went back to drinking my unnaturally blue Gatorade.

Since our group had struggled with the first part of the climb, the guide offered to take the day-packs of the slowest group members and put them on a horse that would stay with us as we climbed. While he and the head horsemen (Gumercindo, pictured above), re-sorted gear to free up one of the horses, we headed out.

In the guides absence the group seemed willing to let me set the pace and lead the charge up the mountain. As a kid, my dad had one simple rule for hiking as a group, “you start as a group, you hike as a group, you end as a group.” So I tried to keep our group together by setting a relatively slow pace, and making sure that everyone was caught up at each switchback.

The midday sun directly overhead was blazingly hot. Even in the best conditions the ~2700 ft (~823 m) of elevation gain in the 2 short miles (~3 km) between Santa Rosa and Maranpata would have felt steep, but with temperatures soaring up over 100ºF it felt even more impressive.

I found the steepness of the switchbacks particularly impressive. When I’d seen the elevation profile for the hike I’d assumed this stretch of trail would be a steep, rocky scramble straight up the mountain like the scrambles in the White Mountains of New Hampshire. Instead it was a consistently graded dirt track more like the trails I’d hiked in California, but much, much steeper. The impressive elevation gains on this hike (1800 ft in the first 1.2 miles, and 2700 ft in the the next two miles) rivaled some of the steepest sections of the trails I’d hiked on the AT and PCT. One advantage of the super-steep switchbacks was that they were so steep they created shadows, which gave us a little bit of shade to rest in.

We were taking the hike so slowly and resting so often that despite the elevation gains, the heat, and the altitude I was feeling pretty good. It also gave me plenty of time to marvel at the beauty of the trail around me and wonder at its curiosities. Per usual, I took pictures of each new flower and strange plant that I saw. I also marveled at the things I didn’t expect to see while hiking through the desert in Peru,  like the groves of bamboo tucked into the ravines. I’d always thought that bamboo was strictly native to China, but it turns out that bamboo is also native to Peru and the Americas!

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As the morning turned into afternoon the energy levels among the people in the group started to drop. One person in particular was really struggling. Her pace had slowed significantly in the last hour and she was feeling nauseous. In addition, she was starting to stumble in a way that I found alarming. Unusual “umbles” (stumbles, mumbles, fumbles, and grumbles)  while hiking are classic warning signs that something is going seriously awry.

Since we were going up in altitude, we hadn’t eaten in 6 hrs, and the temperatures were excessively hot, it was hard to tell if the problem was dehydration, altitude, declining blood sugar levels, or all of the above. The next time she stumbled I suggested we stop in the shade for a few minutes to rest and drink some water. I also offered her some of my favorite electrolyte gummy candies (shot bloks). Luckily she started to feel a little better after that, and her gait and nausea began to improve.

Finally at around 2 pm we made it to our lunch destination at ~9,573 ft (2918 m). By then a lot of people in the group were feeling excessively fatigued and headachey. Since temperatures had reached 102°F and it had been about 7 hours since we last ate, dehydration and low blood sugar were definitely a part of the problem, but exertion at high altitude was also likely to be part of the problem.

  • 75% of people have some symptoms of acute mountain sickness (AMS) above 8000ft (2500 m)
    • Mild AMS: headache, dizziness, fatigue, shortness of breath, loss of appetite, nausea, disturbed sleep, and a general feeling of malaise
    • Moderate AMS: severe headache (not relieved by medication), nausea and vomiting, increasing weakness and fatigue, shortness of breath, and decreased coordination (ataxia)
    • Severe AMS: shortness of breath at rest, inability to walk, decreasing mental status, high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE)

While we rested in the shade waiting for lunch I pulled out the pulse oximeter (Acc-U-Rate CMS 500DL, US$19.95) that I’d brought along. I’d purchased it because I was curious about how the altitude would affect my poor asthmatic lungs, and as a scientist I’d hoped that the entire group would join me in collecting data  about the effects of altitude on our physiology. I measured my oxygen saturation (SpO2) and then passed the pulse oximeter around to the rest of the people in the group. Sure enough, every single person in the group had a lower SpO2 at Maranpata than they had had that morning at the Apurimac River. Mine had dropped from 96% to 93%, but other people in the group had seen more dramatic drops. For example, the woman that had been struggling with nausea on the way up had dropped from 94% to 74%.

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*The decrease in mean SpO2 levels between our campsite at the Apurimac River (94.4% +/-0.3SE, n=7) and Maranpata (86.9%+/-2.6SE, n=4) was statistically significant (p<0.03)

Luckily after resting, hydrating, and eating lunch everyone started to feel better. Besides, the rest of the day’s hike was what the guide called, “Inca flat,” which meant that there were plenty of little ups and downs, but not significant changes in altitude.

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Heading from Maranpata towards Choquequirao the cacti quickly gave way to greener, lusher vegetation, and we caught our first glimpse of the Inca ruins of Choquequirao in the distance. The steep farming terraces of the lowest sector of Choquequirao seemed to be cut into the face of sheer cliffs. It was incredible to think about what kind of oasis this must have been when it was actively being farmed and maintained. Especially since only a fraction of the site at Choquequirao has been excavated.

As we got closer to the first visible ruins of Choquequirao (Phaqchayuq, or “the one with the waterfall”), which sports at least 80 agricultural terraces I noticed the unmistakable  purple star-shaped flowers of the nightshade family mixed in among the vegetation. They reminded me of the potato plants that used to grow in my grandfathers garden. I wondered if this plant might be among the 2,500 varieties of potato cultivated in the Andes, and if its ancestors had escaped from the Inca terraces centuries ago.

Even though the two miles (3km) from Maranpata to the Choquequirao campsite were relatively flat, the pace of our group as a whole was still incredibly slow. As the sun dropped behind the ridge a sense of disappointment welled up within me. One of Choquequirao’s claims to fame is that it contains the only known Inca site dedicated to the sunset and I’d really been looking forward to watching the sunset from that amazing site. It was only as I realized that I wasn’t going to get to watch that sunset that I began to understand that the speed of our group might have a negative impact on our itinerary and on my vacation.

After settling in among the terraces at the Choquequirao campsite and admiring the beautiful mountains around us, Jari and I headed into the dining tent for tea, snacks, and cocoa. It turned out that he was just as disappointed about missing the sunset at Choquequirao as I was and was concerned that the slow pace of our group might prevent him from getting to visit the ‘Llamas del Sol (Sun Llamas)’ at Choquequirao the next day. I had no idea what the Llamas del Sol were, but I was excited to find out, so I said that I’d happily explore them with him.

Eventually everyone else from the group filed in and we ate dinner. Once again the cooks prepared a real feast for us, including something that I’d never eaten before, lupine salad (ensalada de tarwi). “I had no idea that lupine was edible,” I commented as the guide described each dish. “Usually it isn’t,” he explained, “raw lupine beans are poisonous, but the Inca learned that if you soak the lupine beans in the river for two weeks they become edible.” I was curious about what the white beans from the pretty purple flower tasted like, so immediately tried one. Their flavor was absolutely unique. They were slightly bitter, nutty, and vaguely reminiscent of bug spray, but still surprisingly good. I took a heaping serving of them and enjoyed imagining that they might act like a natural bug repellent.

While the cooks prepared bananas flambé for dessert,  Jari quietly asked the guide if we were going to get to be able to check out the Llamas del Sol at Choquequirao the next day. The guide explained that to see the llamas we’d have to hike half-way down the mountain and back up again, and that it would be way too much for our group. “Yes, but I would still really like to do it,” insisted Jari. “Count me in!” I added.

The guide sighed, “I don’t know why Jari is fascinated with dead llamas. We’ll see plenty of live llamas on this trek without having to do any extra hiking.” I still had no idea what the Llamas del Sol were, but I was intrigued, especially since it would involve extra hiking. “The two of us (Jari and I) could go check out the llamas and then catch up to everyone afterwards,” I proposed. Although the guide wasn’t enthusiastic about it, he gave an affirmative nod, “that could work.” Jari and I would get our adventure at Choquequirao!

–Next Installment: Day 3-Choquequirao and the Llamas del Sol–

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Summary: Day 2 by the numbers

  • Apurimac River (5084ft/1550m) to Santa Rosa (6873 ft/ 2095m)
    • Distance: 1.2 miles (2 km)
    • Elevation gain ~1800 ft (~550m)
    • Predicted hiking time (actual): 1.5 hrs (3 hrs)
  • Santa Rosa to Maranpata: 9,573 ft (2918 m)
    • Distance: 2.1 miles (3 km)
    • Elevation gain: 2700 ft (~823m)
    • Predicted hiking time (actual): 1.5-2hrs (4 hrs)
  • Maranpata to Choquequirao Campsite: 9950ft (3033m)
    • Distance: 2.1 miles (3 km)
    • Elevation gain: ~0ft (‘Inca flat’ as described by guide)
    • Predicted hiking time (actual): 1.5hrs (3 hrs)
  •  Totals: 5 miles (8 km)
    • ~4700 ft (~1400 m) elevation gain
    • Predicted hiking time (actual): 4-5 hrs (~11 hrs: 7:30 am to  6:30 pm)
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Water! (PCT Days 40-42)

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When hiking long distance trails your relationship with water changes. This has been especially true for me as I’ve hiked through the first 700 miles of the PCT, which spends a lot of time in the desert. Water is something that I can’t afford to take for granted so before I leave the water source I’m at, I sit down and figure out where my next water is going to come from.

One of the best resources for figuring out water on the PCT is Halfmile’s water report (a list of the water sources along the route, directions for how to get to the water, as well as comments recent hikers have left about how well the water is flowing or if the source has dried up for the year/drought).

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The northern part of the desert was where I ended up having to go for the longest stretches of time without water. Leaving the town of Mojave it was going to be 30-35 miles before the next reliable water source and 144 miles before I was going to be able to get my next food resupply. If I assumed that I was going to hike 15-20 miles a day that meant I needed to carry enough water for 2 or 3 days and enough food for seven or eight days. Yikes, that’s a lot of food and water! And very heavy! 2 days of water is five or six liters (carefully monitoring water use) and 10-12 pounds and 8 days of food is another 15 pounds… So 25+ pounds of food and water. Definitely a very heavy pack, the heaviest pack I’ve had to carry so far!

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The first water source we encountered after leaving Mojave (golden oaks spring) looked rather….green. The water trough was covered with algae and didn’t really look like anything anyone would ever want to drink, though there was a tiny pipe feeding into it at one end that was dribbling into the trough. Theoretically we could refill our water bottles from that drip (if we were very very patient… Not my strong suit)!

Luckily I’d met a Southbound hiker earlier that had told me the secret to this water source… If you followed the barbed wire fence uphill you’d come to a spot where you could duck under the wire, crawl over a bunch of bushes (and a brick/stone wall), and then draw your water directly from the cistern. After seeing the other two options the search for the cistern seemed like a good idea.

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I picked up the cover of the cistern and looked inside… There was definitely water in there. It didn’t look good, but it looked much much better than the water from the trough down below. I looked down into the cistern, it was going to be a reach to draw the water out, but I was pretty sure I could do it.

I sat down on the ground beside the cistern (falling into a well/cistern is definitely on my NO list) and reached about 2 and a half feet down to the water and slowly refilled my water bottles. Though the water seemed nicer than that from the trough I definitely wasn’t feeling confident about it so I both filtered it (with my sawyer squeeze filter) and chemically treated it (with aquamira).

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Since I was 25-30 miles from the last water source, and many miles away from the next water source I couldn’t afford to be too picky. Even still, Having had giardia once, and not wanting to think about what had leached into the water from the eroding cistern, I was definitely motivated to treat my water very carefully.

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The place I got water from the next day was a trough, but it looked much much nicer and cleaner (and was also a lot easier to access!) than the last one. Even though the water looked clean, I still treated it (I always do) because giardia spores etc don’t necessarily make the water look dirty. It was nice not to have to filter out all the little green, orange, and black floaty bits though.

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Sometimes finding the water sources, even when you theoretically know where they are, is like being on a treasure hunt… you follow notes and signs and scratch marks on the ground and hopefully at the end you find one of the most valuable treasures of all… Water!!!

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And sometimes, just sometimes, you run into trail angels on birding expeditions in the California mountains that offer you water and save you from having to go on yet another wild goose chase!

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Most of the time the water sources are appealing enough that you don’t worry too much about the actual water you’re drinking as long as you’ve filtered it and/or treated it. Sometimes, however, you can’t help but wonder about the extras that you’re getting with your water. The first time that happened to me on the PCTwas at deep creek hot springs where there were rumors of lithium in the water. My filter and my chemicals weren’t going to filter that out, but I was generally more interested in its potential effects than concerned about them.

Looking ahead about 40 miles to the next reliable water source listed in the halfmile water report I read, “BLM website and others report Uranium at Joshua Tree Spring.” Hmmm… Uranium in the water…. That definitely conjured up very different images in my mind than lithium in the water.

Well, how far was is from there to the next water source? How much did I actually *need* that Uranium water anyway? Hmmm… Looked to be about another 20 miles to the next really reliable water source, though there might be some other options since I was pretty early in the season… Then again, it’s the third year of drought in the Californian desert.

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Reading the fine print in the water report was vaguely reassuring? It said that uranium was in most of the of the water in the Sierras, it’s just that Joshua Tree spring was the one of the only ones that had been tested.

Hmmm… Drink the water with Uranium in it, be thirsty, or carry lots of extra water with me and pretend that ignorance is bliss for the rest of the Sierra. Since the temperatures were in the 90s I figured I’d go with the uranium water. Chances were pretty good that the small dosings during the period of time I was going to be in the Sierras were ok, right? Also, dehydration, heat stroke, joint injuries or the combination of all of the above seemed likely to be both more immediate and graver threats.

Despite my decisicion, when I got to Walker Pass and found a spring with cattails growing out of it I decided to fill up with water (carried 4L out and drank 1L), no need to drink excessive amounts of Uranium water when there was cattail water to be found.

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The next day dawned and the temperatures climbed as I climbed what felt like mountain after mountain. I was going through a lot of water. When I got to Joshua Tree spring I consulted my water report. Therewas probably water at Spanish Needle Creek 7 or 8 miles ahead, but it sounded a bit confusing… I decided I didn’t need to get a lot of water, but the addition of one Liter of water would make my life a whole lot better… It was time to try out the uranium water.

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When I got down to the spring there were two signs. One which said that the water wasn’t fit for drinking and one that had the standard list of backcountry water caveats essentially telling you to filter and treat your water. I looked at the stuff growing in the water of the trough… It looked like all the usual floaty buggy things. Since there weren’t any three eyed fish mixed in I figured it must be fine (please note appropriately level of sarcasm here). Besides, uranium water is probably good for fighting off precancerous cells if you have any, right?

As the day progressed it got hotter and hotter and I was glad to have my uranium water on hand. The next water source, Spanish needle creek, was pitiful at best (I’d be surprised if there is any water left there in a couple of weeks), and looked more like the runoff water from a recent storm than a creek. I filled up with another liter of water there (which took about five minutes) and figured that that combined with the water I had left would cover me for the 10 miles or so to the next water source.

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As I hiked north and got to the places where the more reliable branches of the creek were supposed to be and found them dry I started getting a little bit nervous… It was really hot out, and it was really exposed, and what if the upcoming water sources were all dry? After having hiked 20+ miles that day, hiking more than the 24 mile total I’d planned on was a truly daunting thought.

As I crossed the dry bed of chimney creek (mile 24 if the day where is been hoping to find water) my heart sank. It was at least 2 miles uphill to the next spring and what if it was dry too? I still had water left (my emergency half liter) and was still pretty well hydrated, but it wasn’t going to be fun. By the time I got there it would be almost dark and probably cooler out… That would be a plus.

As I turned the corner and looked at the mountain in front of me with grim determination I heard voices. Huddled in the shade of a nearby bush/tree were at least half a dozen thru-hikers. “Water, the most amazing water is here!” They called out to me.

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I dropped my pack and joined them in the shade. Water, glorious water… it felt like the best news I’d ever heard. It seemed funny in a way, the places where I thought that I needed to be really careful about water I hadn’t had any trouble, but when the section where there was supposed to be easy water (water every ten miles or so) is when I was happiest to find water. Though the desert has been awesome, I’m looking forward to some of the upcoming sections of the trail where I won’t have to worry about water nearly as much!

P.S. I apologize for the images, I installed a WordPress update and ever since then I’ve been having trouble with my image uploads. I’m working with wordpress now and hope to have the issue resolved soon!

P.P.S. Check out this USGS fact sheet about where the Uranium is near Joshua Tree Spring (the southern sierra), or this report for the central sierrras.

 

Yeah, it’s legal, but it ain’t 100% legal (PCT days 9&10)

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There are some nights when I feel like staying in my tent in a field of boulders. It was just 3 more miles to the trail angels house and the next water source, and it was only 4 o’clock, but I didn’t want to camp near a road again. I’d spent the previous night camped by the road at Warner Springs and it was way too loud so close to town. This spot in the boulders was quiet and beautiful and I loved it. I could stretch my water until morning and just relax for the rest if the afternoon.

I woke up early the next morning and headed to my next source of water, the trail angels house. The trail angels and trail magic on the PCT have been absolutely amazing. It seems like they are incredibly organized and go to an amazing amount of effort to help the hikers out, especially with water. This trail angel’s place was no different. Instead of just a couple of jugs of water, he’d installed a giant full tank of water for the hikers.

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As I was filling up my water I heard the unmistakable laughter of the Russians (three Russian hikers that I’d been hiking with on and off for the last couple of days), so I decided to head down, say hi to the Russians, and meet the resident trail angel.

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The Russians and the trail angel were sitting in front of the house chatting and welcomed me warmly. They offered me some tea, so I sat down to join them for a spell. It was only 8 am so I was barely half awake.

The trail angel got up for a smoke and the conversation turned to state versus federal drug laws. The Russians had never seen weed before, so asked to see the trail angels prescription. “100% legal” said the Russian translator. The trail angel replied that yes, he had a prescription, but that even though it was legal you were better off thinking of it as illegal.

It turns out that he used to own a dispensary (100% legal according to state law), but he’d been raided by the Feds. Having been arrested 11 times for issues associated with pot, his lack of confidence in the law seemed very understandable!

As the conversation waned and turned towards other subject matter one of the Russians walked away from the table and towards the backyard where he picked up a 22 and began shooting at beer cans. This combination of events was a little too much for my brain to process at 8 am!

I drank my tea and enjoyed this new and somewhat surreal trail experience. On the AT lots of people talked about guns and asked me if I was carrying one, but I’d never actually seen anyone firing them. On the PCT this was now my second time watching someone fire at targets in the desert.

I finished my tea and as I prepared to head back out into the desert I wondered what new and surreal adventures were still awaiting me!

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Backpacking Science and Privilege: Water

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On long-distance backpacking trips we don’t take the same things for granted that we do at home and as a result we can gain some insights into our privilege and how it affects the way we hike our hikes, and pack our packs. This is the second post in a series of three in which I  discuss how science and privilege influence the way I pack my pack.

  1. Food: Our ability to regulate blood sugar levels (glycoregulation).
  2. Water: Our ability to regulate water and minerals (osmoregulation).
  3. Shelter/Heat: Our ability to regulate body temperature (thermoregulation).

Unpacking my Invisible Knapsack: Water

In 1989 Peggy McIntosh wrote a famous essay in which she likened privilege to “an invisible weightless knapsack of special provisions, maps, passports, codebooks, visas, clothes, tools and blank checks.” What follows is a list of water-based privileges that hiking the trail has made me more aware of:

  • I don’t have to be thirsty. Living in New England in the age of modern plumbing means that this is usually a privilege that I can rely on. Typically all I have to do is walk into the kitchen or bathroom and turn on the faucet to get as much water as I want. On the Appalachian Trail there were frequently springs, streams, rivers, or ponds from which water could be acquired, although during the late summer months many of the springs/streams were dry and more advanced planning was necessary to avoid running out of water and being thirsty. On the Pacific Crest Trail this year (2014) as I hike through the desert in a record-breaking drought, the availability of water will be more of an issue.
  • The water I drink won’t make me sick. First world privilege and modern sanitation means that the water I have access to in my home is unlikely to make me sick. On the trail, the water coming directly out of the springs is unlikely to make me sick, however, water from streams, rivers, and ponds may be contaminated with giardia and e. coli. The streams in Maine (for instance) are often fed from beaver ponds and may be contaminated with giardia.
  • I’ve never been so desperate for water that I’ve knelt down and tried to lap it out of a mud puddle. Walking through the streets of Boston I’ve never been tempted to drink water from a mud puddle. During an uncharacteristic heat wave on a 20 mile day when I miscalculated the amount of water I needed to carry and ran out 5 miles short of the next spring… that mud puddle was a very tempting source of water indeed!
  • I don’t have to pay attention to how much water I drink. When there is a faucet with running water in the room next door I don’t worry or pay attention to how much water I drink because I can always get more whenever I want. On the trail I sometimes end up rationing my water if I start to run out sooner than I expected or if I don’t know when or where I’ll have access to water again.
  • There will be water available when I need/want it. The joys of modern plumbing in a water rich environment means that this us usually true for me. On the Appalachian Trail in the spring, water was abundant, but some knowledge of where the next sources of water were likely to be was useful. On the Pacific Crest Trail in the desert during a drought, I expect that I will need to be much more careful when it comes to figuring out where to get my water and how much to carry.
  • My behavior does not affect the availability and quality of my (or other people’s) drinking water. Typically at home in New England I don’t have to worry about how my behavior is affecting the public water supply. There are also regulatory agencies (like the EPA) which help ensure the quality of my drinking water. On the trail, however, people washing themselves and or their dishes in the rivers and streams can have a direct impact on the quality of the water I drink… never mind whether or not they decide to use the riverbank as their personal latrine.
  • I know that if I run out of water other people will share theirs with me. If people on the trail have extra water they are typically willing to share it. Also, on the Appalachian Trail in regions where water is scarce trail angels often provide water caches along the roadsides for thirsty hikers.
  • I will be allowed to use public restrooms. White middle-class privilege means that I can use most public restrooms without being harassed. Many businesses, however, require that you make a purchase in order to use their restrooms and, as a hiker, seem to be much more confrontational about making sure that you actually purchase something before allowing you to use the restroom.
  • The research that I use to determine how much water I need is based on people that are likely to have physiological requirements similar to mine. White privilege means that this is usually true. Most of the data is, however, based on men and less data seems to be available about women.

Packing My Pack: Water

To ensure proper hydration while backpacking you need to match your fluid intake (from food and beverages) to your fluid losses (through urination and sweating). Dehydration, defined by a 2% drop in body weight, results in impaired physiological and psychological performance, further dehydration can impair the bodies ability to regulate temperature and increase the risk of developing heat stroke. For every 1% drop in body weight from sweat, core temperature goes up by 0.15 to 0.20 degrees Celsius and increases heart rate by 3-5 beats per minute. It is also important to note that over-hydrating can result in electrolyte depletion and hyponatremia. Symptoms of heat exhaustion and hyponatremia are easily confused (dizziness, headache, nausea, and muscle aches), however symptoms of heat exhaustion are relieved shortly after improved fluid consumption whereas symptoms of hyponatremia continue or worsen with additional fluid consumption. On the other temperature extreme, dehydration can hasten the symptoms of hypothermia (click here for an overview of hydration for backpacking).

Though data specific to the hydration requirements for recreational backpacking are minimal, the US military has many similar hydration requirements and a well-established set of guidelines for hydration and fluid replacement (2010). These guidelines are based on the environmental heat exposure determined by wet bulb global temperature (WBGT=0.7Tw+0.2Tg+0.1Td), which includes a measure humidity (Tw, the natural wet bulb temperature), radiant temperature (Tg, the globe thermometer temperature), and dry air temperature (Td, the dry bulb temperature) and as well as the  intensity of the work performed (see the graph below):

Image result for military desert water requirements data

Water Requirements (NOTE: Current Standards State Consumption should not exceed 11.4L/day)

 

A common clinical method for estimating fluid replacement volume is the Holliday-Segar method, which suggests that water loss is related to caloric expenditure. This method was initially developed for hospitalized patients where they estimated that each day patients lost 100 ml of fluid for each 100 calories they burned. This is where the rule of thumb that you need 1 ml of water for each calorie that you burn comes from (their actual model had a variation based on initial body weight as well). Assuming that the same relationship between fluid loss and calories burned exists for backpackers (I’m a bit dubious) you would estimate that for a typical day in which you burn 5000 calories, you would need a total of 5L of water. On the AT, at moderate temperatures, I consumed an average of 4L of water a day (2L while hiking, 1L to rehydrate my dinner, and 1L in the evening/morning prior to hiking). If outside temperatures exceeded 80 degrees Fahrenheit I would typically drink 1 additional liter of water a day at lunchtime. My water consumption was typically less than that of my male counterparts on the trail who usually drank at least 1L of water/day more than I did. If you assume that athletes have a higher percentage of muscle (which is 70-75% water) and a lower percentage of body fat (which is ~10% water) compared to patients in the hospital, you might estimate higher fluid volume replacement requirements for athletes. Allowing for differences in body fat percentages, this might help account for some of the gender based variations in water replacement requirements that I observed as well.


 

 

Are there other ways that privilege and science influence your relationship with water and how much water you carry?