Acclimation

Sleep at Altitude

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Reported Sleep Disturbances

Many travelers report a decrease of quality of sleep when traveling from sea-level to high altitudes. Newcomers to altitude typically describe trouble falling asleep and frequent wakings throughout the night.7 One study determined that 46% of 100 Iranian ski tourists reported frequent awakenings and other sleep disturbances such as insomnia during their first night sleeping at 3,500 m.5,7 Another study analyzed data from reports of 305 Chinese soldiers transported from 500 m to 3,700 m in Lhasa and found similar results. Approximately, 32% of the soldiers reported insomnia in the first night at altitude and 74% of 246 workers who were air-lifted to the South Pole at 2,835 m reported difficulty falling and staying asleep throughout the first week.1

Change in Breathing Pattern

Many theories state that the “periodic breathing pattern,” common during sleep at high altitude, is a potential cause of sleep disturbances. Periodic breathing is a form of Cheyne-Stokes respiration and reflects changes in neural signaling due to hypoxia and alkalosis during sleep.4 Hypoxia is a respiratory stimulant while alkalosis is a respiratory depressant.4 This mixed signaling is the source of the altered breathing during non-REM sleep encountered at altitudes over 2500 m. The frequency of periodic breathing during sleep increases as the altitude increases.3,4,7

Decreased Sleep Efficiency 

Compared with sea level, several studies have depicted that sleep at higher altitude is characterized by decreased sleep efficiency, prolonged superficial stages of sleep, and reduced stages of deep sleep.12 The image below is a qualitative representation of sleep structure recorded at sea level and at high altitude. The area encircled by the outer line reflects the time in bed and the area of the shaded inner pie chart the time asleep.7,13 The fractions of superficial stages of sleep are symbolized by “NR1&2,” the fractions of deep non-rapid eye movement sleep are represented by “NR3&4,” and the stages of  rapid eye movement sleep are exemplified by “REM.”

Fig. 1. Depicts a qualitative comparison of sleep quality at sea level vs. altitude > 1,500 m13

Shift in Brain Waves 

Everyone is aware of the importance of quality of sleep when it comes to memory processing. One study has associated a decline in sleep-related memory consolidation with the decrease in slow wave-derived encephalographic measures of neuronal synchronization in healthy subjects observed overnight at high altitude.15  Another study by Stadelmann et al. discovered that quantitative spectral analysis of frontal and central EEG derivations reflected an altitude-dependent decrease in slow wave activity.14

Daytime Performance

A study, analyzing sleep disturbances experienced by lowlanders with obstructive sleep apnea during a stay at 2,590 m, discusses the association between sleep disturbances with poor performance in driving simulator tests.11 Studies performed at altitudes of 3800-3900 have revealed that supplementing with nocturnal oxygen improves daytime performance in neuropsychological tests, increases overall sleep quality, and reduces the occurrence of periodic breathing. 9,10 Although further studies are needed, the stated findings suggest that altitude-related alterations in sleep may negatively affect overall daytime performance.7

Can We Acclimate to High Altitude? 

Over time, research points to some sort of acclimation concerning sleep at high altitude; although research analyzing acclimation is very limited. Studies analyzing altitudes between 4,5559 m to 6,835 m have determined that the frequency of periodic breathing increased with the time spent at high altitude altitude.2,12 Opposingly, in studies at lower altitudes such as 1,650 m, 2,590 m and 3,450 m, periodic breathing decreased from the first to the second night.6,8 These observations suggest that there is an altitude-dependent effect of acclimatization on sleep structure. Interestingly, the same study that determined an increase in periodic breathing with time spent at an altitude of 4,559 also noted a decrease in arousal index and normalization of nocturnal oxygen saturation with increased time spent at high altitude.12 Stadelmann et al. determined that there was a statistically significant increase in the number of sleep cycles at higher altitudes with the longer the stay at altitude.14

Dr. Ebert-Santos’s Decision to Continue the Research

Despite recent advances in our understanding of sleep at high altitude, further research is needed to understand how demographics may alter sleep at high altitude, to determine the process of sleep-acclimatization, and to uncover the characteristics of sleep in local-highlanders.7 Dr. Ebert- Santos continues to be an advocate for the Summit County community regarding the effects of high altitude on health and has decided to pursue a study researching the effects of altitude on oxygen saturation during sleep of adults ranging from the ages 25-65 years old. Stay tuned for her process, her results, and her conclusions! 

Caroline, PA-S

References:

  1. Anderson PJ, Wiste HJ, Ostby SA, Miller AD, Ceridon ML, Johnson BD. Sleep disordered breathing and acute mountain sickness in workers rapidly transported to the South Pole (2835m). Respir Physiol Neurobiol 210: 38–43, 2015.
  2. Bloch KE, Latshang TD, Turk AJ, Hess T, Hefti U, Merz TM, Bosch MM, Barthelmes D, Hefti JP, Maggiorini M, Schoch OD. Nocturnal periodic breathing during acclimatization at very high altitude at Mount Muztagh Ata (7,546 m). Am J Respir Crit Care Med 182: 562–568, 2010.
  3. Erba P, Anastasi S, Senn O, Maggiorini M, Bloch KE. Acute mountain sickness is related to nocturnal hypoxemia but not to hypoventilation. Eur Respir J 24: 303–308, 2004.
  4. Gallagher, Scot A. High altitude illness: Physiology, risk factors, and general prevention.  Up-to-date.Waltham, Mass.: UpToDate; September 20, 2017. www.uptodate.com. Accessed March 20, 2019.
  5. Jafarian S, Gorouhi F, Taghva A, Lotfi J. High-altitude sleep disturbance: results of the Groningen Sleep Quality Questionnaire survey. Sleep Med 9: 446–449, 2008.
  6. Kohler M, Kriemler S, Wilhelm EM, Brunner-Larocca H, Zehnder M, Bloch KE. Children at high altitude have less nocturnal periodic breathing than adults. Eur Respir J 32: 189–197, 2008.
  7. Konrad E. Bloch, Jana C. Buenzil, Tsogyal D. Latshang, and Silvia Ulrich. Sleep at high altitude: guesses and facts. Journal of Applied Physiology 2015 119:12, 1466-1480. 
  8. Latshang TD, Lo Cascio CM, Stowhas AC, Grimm M, Stadelmann K, Tesler N, Achermann P, Huber R, Kohler M, Bloch KE. Are nocturnal breathing, sleep, and cognitive performance impaired at moderate altitude (1,630–2,590 m)? Sleep 36: 1969–1976, 2013.
  9. Li P, Zhang G, You HY, Zheng R, Gao YQ. Training-dependent cognitive advantage is suppressed at high altitude. Physiol Behav 106: 439–445, 2012.
  10. Luks AM, van MH, Batarse RR, Powell FL, Grant I, West JB. Room oxygen enrichment improves sleep and subsequent day-time performance at high altitude. Respir Physiol 113: 247–258, 1998.
  11. Nussbaumer-Ochsner Y, Schuepfer N, Ulrich S, Bloch KE. Exacerbation of sleep apnoea by frequent central events in patients with the obstructive sleep apnoea syndrome at altitude: a randomised trial. Thorax 65: 429–435, 2010.
  12. Nussbaumer-Ochsner Y, Ursprung J, Siebenmann C, Maggiorini M, Bloch KE. Effect of short-term acclimatization to high altitude on sleep and nocturnal breathing. Sleep 35: 419–423, 2012.
  13. Rechtschaffen A, Kales A. A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects. Washington, DC: Public Health Service, US Government Printing Office, 1968.
  14. Stadelmann K, Latshang TD, Lo Cascio CM, Tesler N, Stoewhas AC, Kohler M, Bloch KE, Huber R, Achermann P. Quantitative changes in the sleep EEG at moderate altitude (1630 m and 2590 m). PLoS One 8: e76945, 2013.
  15. Tesler N, Latshang TD, Lo Cascio CM, Stadelmann K, Stoewhas AC, Kohler M, Bloch KE, Achermann P, Huber R. Ascent to moderate altitude impairs overnight memory improvements. Physiol Behav 139: 121–126, 2015.
Mountaineering

Beyond Acclimatization: Avalanche Safety

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Spring of 2019 in the Colorado high country has certainly been one to remember. Unsure of where work would take me, I waited until the last week to commit to a ski pass for the season, and after all the storms we’ve seen, I’m glad I did. And I can tell that many others are just as excited. I’ve never seen so many people on the weekend slopes and on the surrounding highways.

Meanwhile, the central mountain region has seen a record number of avalanches and fatalities, and Colorado retains the highest statistics in the country. People from all over the world come for world-class skiing, but many experienced locals have been avalanche victims. We often assume they are skiers and snowboarders, but avalanche fatalities happen just as often to snowmobilers and backcountry hikers. Another misconception is that these avalanches are happening exclusively in the backcountry, which they are not. Three young men this year barely escaped an inbounds avalanche at Breckenridge ski area, while two weren’t so fortunate in New Mexico’s Taos Ski Valley.

But the wild Colorado backcountry still beckons and many continue to answer. Having spent over ten years in Summit County, home to Colorado’s greatest number of peaks over 14,000 ft., my family and I are regulars in the backcountry, in all seasons. Experiencing these mountains in all kinds of conditions can make you much more aware of the risks inherent in the outdoor recreation scene here, but it clearly does not guarantee your safety.

This coming April, I’ll be on a trek to one of the 10th Mountain Division huts, a series of remote cabins, most of which are only accessible by foot, snowshoe or ski. In the summer, the trails tend to be well-maintained and obvious, but I’ve seen first-hand that conditions in snow, even during a mild season, can make the commute much more difficult and much more dangerous. Carrying all your supplies on your back certainly increases your vulnerability and decreases your ability to respond quickly to unexpected events, as you are more liable to sink deeper into loose snow-pack.

Shrine Mountain Inn, one of the more easily-accessed huts in the 10th Mountain Division system, even offers running water and electricity, as is within most cellular networks.

As you may have been taught, luck favors the prepared. If there’s one way to tell a local from a visitor in the high country here, it’s how prepared they are to be outdoors in variable conditions, and as the sole resident on the upcoming hut trip, I will be passing on all the proper safety precautions to my less-experienced San Francisco counterparts.

Expeditions to more popular huts at lower elevations during mild winters tend to be more about preparing comforts: boots, snowshoes, skis that fit well; warm, dry layers; plenty of water; etc. What makes me especially wary of the increased danger and the necessity of avalanche equipment is the alternating warm weather and snow storms. This means several alternating layers of heavy snow and light pack, making large slabs of snow (and ice) more prone to letting loose and leveling everything in their way.

While there are some obvious measures you can take and gear you can pack to boost your ability to respond in case of an avalanche, professionals across the state can’t recommend official avalanche safety certification highly enough. It’s available across the globe, thanks to the American Institute for Avalanche Research and Education (AIARE), and Colorado is one of the best places to get certified.

Technology has come a long way when it comes to avalanche safety, but the three things AIARE recommends you carry while in the backcountry are a transceiver (a beacon), a probe (for finding buried victims) and a shovel. Local conditions are updated daily on Colorado’s Information Marketplace Avalanche Information Center. Be sure to check the very day you plan to be in areas of high risk, and as frequently as possible.

On a closing note, keep in mind that avalanche safety measures aren’t always as intuitive as carrying a shovel. One major statistic we should all keep in mind is that most avalanches don’t happen on their own, and are caused by the victims themselves, often because there is more than one person traversing a slope at a time. In this case, safety is not in numbers: one person on a slope at a time.

I love Colorado, I love the mountains, I love the ski slopes, I always appreciate the vast open wilderness of the Rockies, and I’m looking forward to many more upcoming excursions in them. Hopefully this has armed you with some knowledge to better equip your daring high country adventures. It is just the tip of the proverbial ice berg, however, and on top of certification and gear, there is no end to the value that actual experience adds.

Roberto Santos is from the remote island of Saipan, in the Commonwealth of the Northern Mariana Islands. He has since lived in Japan and the Hawaiian Islands, and has made Colorado his current home, where he is a web developer, musician, avid outdoorsman and prolific reader. When he is not developing applications and graphics, you can find him performing with the Denver Philharmonic Orchestra, snowboarding Vail or Keystone, soaking in hot springs, or reading non-fiction at a brewery.

Mountaineering

A Sea-Level Dweller Climbs Cotopaxi

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During the winter of 2018, the Little Rock Climbing Center Alpine team ventured south to Ecuador for a mountaineering expedition. However, poor weather and high avalanche risk thwarted our summit attempts of Cayambe (18,996’, 5789 m) and Cotopaxi (19,347’, 5896 m). This winter (2019), we returned to Ecuador to attempt to summit Cotopaxi again, with a new and improved acclimatization plan and high hopes for better weather. Little Rock, AR sits at a mere 335 ft (102 m) above sea level … but we are lucky to have Pinnacle Mountain, with 750’ (228 m) of elevation gain to train on. A small mountain is better than no mountain!  My training plan entailed hiking Pinnacle Mtn 2-3 times during the week, and then hiking or mountain biking on the weekend for approximately 3 months. I also rock climbed at the climbing gym 2 days a week, but Cotopaxi is not a technical climb, so that was mostly for fun.  I took a week-long trip out to Colorado in September to reassess how my body reacts to high altitude.  During this week we rock climbed in Boulder Canyon, Idaho Falls, and climbed the first and second Flat Irons, as well as hiked up to Sky Pond at Rocky Mountain National Park, hiked Mt. Bierstadt, and hiked out to Crystal Mill with Dr. Chris. I chose not to run too much this year for training because I have a meniscal tear in my left knee that gets aggravated on long runs. 

We arrived in Quito, the capitol of Ecuador on December 30. Quito sits at 9,350’ (2849 m), so we took our first day pretty easy, and walked from our hotel to the older part of town with historic churches and cathedrals. Walking up the many flights of stairs in the Basilica del Voto Nacional got my heart pumping and legs and lungs burning! New Year’s Eve in the La Mariscal area of Quito was quite entertaining and a little rowdy, with fireworks, burning of effigies, and jumping over the fires. Our first day hike was up Rucu Pichincha (15,413’, 4697 m), a stratovolcano right in Quito! The TeleferiQo (a gondola) brings you up to 12,943’ (3945 m) where you begin the hike. The hike up Rucu Pichincha starts out mellow, on smooth trail with short steep, punchy climbs. Once you near the top, the steepness increases and the last few hundred feet involve very easy scrambling on sharp volcanic rock. The winter in Ecuador is typically the rainy season, so scattered showers and electrical storms are very common. However, we lucked out with perfect weather on Rucu Pichincha, and fantastic views of the big mountains – Cotopaxi, Antisana, and Chimborazo. The next day we drove to the base of the Ilinizas, and just missed the horse that was supposed to carry our packs up to the refugio. It was about a 3,000’ (914 m) climb up to Refugio Nuevos Horizontes, in relentless wind and dense fog. About half way up to the refugio, a lone figure emerged out of the fog. The horse that was supposed to carry out gear was carefully making his way down the mountain, such a surreal sight! We spent the night sharing bunk beds, packed like sardines in the tiny refugio (15, 696’, 4784 m). The next morning, the wind hadn’t let up, and the fog was still suffocatingly thick. A few groups had attempted an early morning ascent of Iliniza Norte, but said it was too icy and windy to summit. Our mountain guide, Alejo, suggested we traverse around the backside of Iliniza Norte to avoid the worst of the wind, and his advice was on point. The wind was whipping so hard at the summit (16,818’, 5126 m), we spent less than 5 minutes on top before beginning our decent back to the car. The wind was so strong on our descent (upwards of 60mph!), it knocked me off my feet several times. Next time I will use my hiking poles when it is so windy! We spent the next day resting and recuperating at Los Mortinos Hacienda, a cozy B&B at the edge of Cotopaxi National Park where we watched llamas graze, went horseback riding, and dined on fresh trout from a nearby river. 

The next day we drove up to the Cotopaxi parking lot, and slogged up the soft, ashy trail for an hour or so before reaching Refugio Jose Rivas (15,744’, 4798 m) at the base of Cotopaxi. At the refugio we ate some dinner, hydrated, and then tried to rest as much as possible. Alejo woke us up at 10pm and by 11pm we were on our way up the volcano. The skies were finally clear and calm after days of clouds and windy weather, all of the stars were out and we watched an impressive lightning storm down in Quito. We began the trek in mountaineering boots as the glacier starts about two hours uphill. While I felt fine the day before hiking up to the refugio, I had a pretty decent headache when we woke up. My right foot kept falling asleep in my mountaineering boot, and I was starting to overheat because I had too many layers on. This was the first time on the trip that I felt bad, and doubts about a successful summit started to creep in my mind. Alejo asked if I wanted to turn around, but even though I didn’t feel good, I didn’t feel bad enough to turn around. After about two hours of hiking, we reached the glacier and donned our crampons. And then I started to finally feel GOOD! As long as I kept switching my stepping technique, alternating between duck-footing, side-stepping, and French technique, my right foot wouldn’t fall asleep. The higher we climbed, the better I felt! About an hour away from the summit is when it really began to get steep. Alejo said it would be really steep, then a little easier, and then really steep again. We trudged on. And it got steep — really, REALLY steep. Just keep moving. Step up, rest, step up again, rest. Repeat. The mountain seemed to keep going up and up and up. But then around 8am we were at the top of Cotopaxi! I had seen photos of the summit, but seeing smoke coming out of the crater with my own eyes was mind-blowing. We ACTUALLY made it! We waited for Ian and his guide to summit, and then spent the better part of an hour taking photos and enjoying what Alejo said was the nicest weather he’d ever experienced at the summit. 

Ian brought along an Accumed Pulse Oximeter, so being the science nerd that I am, I measured my oxygen saturation percentage at various elevations over the course of the trip. While the percentage of oxygen in the air is the same, the fall in atmospheric pressure at high altitude decreases the driving pressure for gas exchange in the lungs, leading to lower oxygen saturation levels.  I measured my oxygen saturation level on my right index finger after being seated for approximately 5 minutes. The Accumed Pulse Oximeter is a small battery-powered device that measures the ratio of red light and infra-red light that is absorbed through the finger to calculate oxygen saturation levels.

Here is a table of my oxygen saturation levels at various elevations throughout the trip:

Day Location Elevation  (ft/m) O2 saturation (%)
1 Quito 9,350/2849 80
2 Summit of Rucu Pichincha 15,413/4697 75
3 Refugio Nuevos Horizontes 15, 696/4784 74
7 Summit of Cotopaxi 19,347/5896 57

Before reading too much into this very limited data set, there are a number of limitations with these observations I would like to point out. First, sample size is very limited, and I only took one reading at each elevation.  Second, pocket pulse oximeters are not very accurate below oxygen saturation levels of 70%, and ambient light interference (as we experienced at the summits of Rucu Pichincha and Cotopaxi) can interfere with accuracy. Also, the literature suggests that pulse oximetry utility is limited in diagnosis of acute mountain sickness, and that measuring oxygen saturation after light exercise compared to rest may be more predictive of acute mountain sickness. I believe that I did not experience altitude sickness at any point during this trip. I had a mild headache after sleeping above 15,000’ (4572 m), but that resolved once we started hiking up the mountain. We stayed at the summit of Cotopaxi for approximately 1 hr, and while I had a slight headache and was day-dreaming (more than usual), I felt pretty good overall and had no problems on the descent. Pulse oximetry is painless and non-invasive, and can be a useful tool in evaluating respiratory and other complaints at high altitude, but care should be taken to minimize erroneous measurements to avoid misinterpreting the data.

Keshari Thakali, PhD is an Assistant Professor in the Department of Pediatrics at the University of Arkansas for Medical Sciences in Little Rock, AR. She is a cardiovascular pharmacologist by training and her research laboratory studies how maternal obesity during pregnancy programs cardiovascular disease in offspring. When not at work, you can find her mountain biking, rock climbing, hiking or paddling somewhere in The Natural State. She has a long-term career goal of merging her interests in mountaineering with studying cardiovascular adaptations at high altitude, and would appreciate any tips on how to accomplish this!

High Altitude, Medicine, Mountaineering

La Paz: Healthy Living At 12,000 feet

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Dr Gustavo Zubieta-Calleja explains how lessons learned in La Paz can make space exploration easier

I just returned from the “Chronic Hypoxia” conference in La Paz, Bolivia at 12,000 feet elevation (3,640 m). The sponsor and organizers were Drs. Gustavo Zubieta-Calleja and his daughter Natalia Zubieta De Urioste who run the Institute of High Altitude Pulmonology and Pathology there. Presenters and attendees came from 16 countries covering topics ranging from molecular biology to genetics.
Dr. Zubieta previously published a scientific analysis of centenarians living at various altitudes. He compared Santa Cruz, Bolivia, at sea level, with La Paz/El Alto, each with populations of over three million, and found there are eight times more people over 100 years old at high altitude. (BLDE University Journal of Health Sciences, see blog post 1/5/18) Since his father Gustavo Zubieto Castillo founded the institute in 1970, they have been advocates of the health promoting effects of a low oxygen environment.
A presentation on “BioSpaceForming” even identifies chronic hypoxia as a “fundamental tool”, that “gives humans and other species an advantage on earth and beyond.” Dr Zubieta explained that the space station is engineered to have the barometric pressure (760 mmHg) and oxygen content of sea level. When the astronauts change into their space suits to work outside the ship they experience a pressure drop of over 200 mm Hg in a laborious process of donning the suit. Seeing that millions of inhabitants are healthy at 486 mm HG in Bolivia, he advocates that maintaining lower pressures and lower oxygen levels in the space station would be economical and promote the health of the astronauts. Several altitude scientists see this as a future that “uncouples biology and physics.

Acclimation, Medicine

Life Threatening Causes of Low Oxygen At Altitude

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Anyone who travels to areas of high altitude is at risk for high altitude pulmonary edema (HAPE). Classic HAPE symptoms include a dry cough and shortness of breath with activity; leading eventually to trouble breathing at rest. If left untreated, serious complications can occur. Many other conditions can mimic HAPE, and it is crucial for health care professionals to be able to distinguish between HAPE and other disorders that may cause similar symptoms. Illnesses that may present similarly to HAPE include pneumonia, a blood clot in the lung (pulmonary embolism), and chronic obstructive pulmonary disease (COPD) or asthma. Your health care provider will take a thorough history, but the following outlines the differences between HAPE and other similarly presenting conditions.

  • Pneumonia: In both HAPE and pneumonia, shortness of breath, fast breathing, and a fever occur. Normal oxygen saturations are above 90%, and if you have HAPE or pneumonia, these could be as low as 60 %. However, if you have pneumonia, you will feel a lot worse than if you have HAPE. HAPE typically responds to high flow oxygen and you will get better over a few hours. Whereas if you have pneumonia with low oxygen saturations, you will need immediate hospitalization.
  • COPD/Asthma: High altitudes may exacerbate your COPD or asthma. How providers tell the differences is through something called pulmonary function tests. This tests how well your lungs work. Your provider will have you breath into this device before and after being given albuterol. If your lung tests improve after the albuterol, then COPD or asthma are the more likely diagnosis. It is important to tell your provider if you have a history of COPD or asthma, and if you are a current or former smoker.
  • Pulmonary Emboli (PE): Patients with a blood clot in their lung typically have the same symptoms as HAPE but will sometimes also have chest pain when taking deep breaths. You may also have blood in your sputum and/or calf pain or swelling. You are more at risk for a PE if you have had a recent orthopedic surgery (such as a hip or knee replacement), you have an irregular heart rate, have a clotting disorder, smoke, or are on birth control. If you have these risk factors and additional symptoms, your provider may order a lab test called a d-dimer  and a chest CT scan to help distinguish between a blood clot or HAPE.

If you are experiencing any of these symptoms, it is important to go see a health care provider immediately. A thorough history and exam will help aid in the correct diagnosis and prevent any potential complications. And most importantly, will help you get back on track to enjoy your high-altitude vacation and living!

Miranda Bellantoni, FNP-Student

  1. Luks AM, Swenson ER, Bärtsch P. Acute high-altitude sickness. Eur Respir Rev 2017; 26.
  2. UpToDate. Distinguishing HAPE from Pneumonia 2018.
  3. Brusasco V, Martinez F. Chronic obstructive pulmonary disease. Compr Physiol 2014; 4:1.
Child Growth & Development

Newborns at altitude: less breathing problems, higher chance of brain hemorrhage

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The September 2018 issue of the Journal of High Altitude Medicine and Biology has an article reviewing statistics on newborn health in the Mountain Census Division: AZ, CO, ID, MT, NM, NV, UT and WY.  The lead author, Robert Levine and his coauthors found that newborns in this region have “by far the lowest infant mortality rates for respiratory distress.”  Conversely, there is a higher incidence of intraventricular hemorrhage, or bleeding in the brain, not caused by trauma. This can be a complication of prematurity.

The authors analyzed about 70 million births and 12,000 deaths in over 3000 counties between 2007-2015. They compared maternal education, age, and marital status. The mean elevation of the mountain division counties is 5,725 feet, with the mean for the rest of the US being 2,500 ft. Colorado ranges from a low of 3317 ft to 14440 with a mean of 6800 ft. There were 30 counties above 8000 ft.

Their conclusion :”…we believe the most plausible interpretation of the present data is that they raise questions abut whether maternal residnce at high altitude has uniformly adverse health effects on infant mortality.”

In other words, maybe it’s not all that bad to live in the mountains!

Child Growth & Development, Health, High Altitude, Medicine

The Mitochondrial advantage at altitude

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Dr. Deborah Liptzen, pediatric pulmonologist from Children’s Hospital of Colorado,

Presents a talk on high altitude to the Ebert Family Clinic staff

I learned several new facts about adaptation to altitude that make us better athletes. First, our muscles have more capillaries to deliver blood to the cells. Second,  the cells have more mitochondria which are organelles involved in the chemistry of respiration and energy production.

Other ways our bodies respond to altitude include: increased breathing rate (instant), increased red blood cells (peaks in three months), hemoglobin in red cells holds on to more oxygen, and blood vessels in the lungs constrict (immediate).It is this constriction of blood vessels in the lungs that can go haywire putting pressure on the capillaries causing fluid leaks that lead to pulmonary edema or HAPE.

Acclimation, Health, High Altitude, High Altitude Training & Fitness, Mountaineering

Rethinking Your Energy Supply

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On May 27th 2017, Adrian Ballinger summited Mount Everest without supplemental oxygen. This is an accomplishment that less than 200 people have achieved and followed a failure to summit the previous May of 2016. The 41 year old seasoned climber attributed his failures to the cold, which could have been aided by more muscle and fat content, better insulated jacket and gloves, but he wondered why his climbing partner, Cory Richards so easily made it to the top. Ballinger came to realize it that wasn’t his gear or body composition, but it was that Richards had a different approach to training and nutrition that gave him the edge to summit. Richards trained with a organization called Uphill Athlete that trains its athletes to become a fat burners. After hearing of Richard’s training regimen Ballinger was determined to pursue the same for a another summit attempt in 2017. Ballinger was a carb burner, which means he was relying on burning carbohydrates for energy. When he attempted to summit Everest being a carb-burner, he simply ran out of energy to fuel his body through the last grueling stretch. This was due to depleted glycogen levels that a carb-burner relies on. The average human can only contain enough carbohydrates to supply glycogen stores for about 45 minutes. Once your glycogen stores are depleted, you need to refuel, which in Ballinger’s case, would mean pulling a hand out of a mit in the frigid Everest air to replenish his energy every 45 minutes. This is also known as “bunking,” which means completely exhausting your energy supply, which is what happened to Ballinger. Richards on the other hand, was a fat burner. With alterations in Ballinger’s nutrition and training regimen, he was successful in 2017.

But what is a fat burner?

A fat burner is an athlete that primarily uses fat for energy, and this metabolic process is called fat oxidation. When an athlete is exercising on a typical high carb and low fat diet, they are burning about a 50/50 mix of carbs and fats during steady exercise. If that athlete decides to sprint at full speed being a carb burner or a fat burner, they are primarily burning carbohydrates, known as glycogen. This is the body’s evolutionary design to have instant energy to run away from the tiger when it storms your cave. In Ballinger’s scenario, the high intensity of Everest climbing was like a sprint, depleting all of his glycogen stores causing him to “bunk”.

Why is a fat-burning diet better for climbing?

Being a fat burner for a long distance endurance athlete is beneficial because it eliminates the need to refuel every 45 minutes, which is bothersome. Ever wonder why there is a plethora of fancy sugary “sports” drinks, gummies, and energy bars at sporting stores? They are called “energy” foods, because they are loaded with simple carbohydrates and sugar. On the other hand, a fat burner does not need refueling foods or drinks during exercise, but relies on the extensive supply of fat throughout the body. Even the most elite athletes with very low body fat will have enough to supply the body energy for a event. Picture this, there is a giant fuel tanker truck cruising on I-70. The truck has its own fuel tank which sits below the cab of the truck, which will be depleted in a couple hours. What if the truck could access the large tank that it’s hauling? That would give the trucker a enough fuel to drive for days! In the context of nutrition and your body, the small tank is the your glycogen storage and the large tank is fat storage. This is why some people can fast for days without skipping a beat; they have tapped into their fat supply.

What does it take to become a fat burner?

To become a fat burner, it’s quite simple: cut the carbohydrates. Well, I guess some may think it’s not so easy. You have to cut out pizza, bread, candy, tortillas, and all that good tasty stuff. When a person limits their carbohydrate intake to less than 10% of caloric intake, and increase fat consumption to 70% of their intake, their body shifts into a different mode of creating energy, by burning fat instead of carbs. The by-products of fat oxidation are called ketones. When a person converts to being a fat burner, it is called being in ketosis. This process may take a few days to weeks, which varies from person to person.

Is there any research behind this crazy idea of eating all the bacon and butter you can handle?

Yes, yes there is!

In the research article by Volek et al. (2015), the authors wanted compare a low carbohydrate ketogenic diet and a typical high carbohydrate diet in 20 elite endurance athletes. The authors tested the athletes with a 180 minute, moderate intensity (64% VO2 max), treadmill run.

VO2 max is known as the capacity of your cardiovascular system and its ability to distribute oxygen throughout the body. Higher means a stronger cardiovascular system, so 64% of your maximum effort would be considered moderate exercise.

A 64% VO2 max to you or I would be a brisk walk or a slow hike up that beautiful 14’er, but for these Ironman athletes it was an easy run on a treadmill. The authors compared the rate of fat oxidation and carb oxidation between the two diets, as well as their ability to recover and replenish their glycogen stores. The authors found that the fat adapted athletes had 2.7 times the rate of fat oxidation than the high carb diet athletes. The low carb group also had fat oxidation at higher VO2 max, meaning they could go faster without tapping into their precious glycogen stores. The study also found that after the exercise, the athletes in both groups had similar glycogen level in their muscle. This is significant because the classic rule of thumb with exercising is that you need a post-workout shake with protein and carbs to replenish your muscles, or your exercising efforts are gone to waste …

WRONG!

It turns out your body has its own way of replenishing its glycogen stores without the post-workout carb load. That means after you climb that 14’er, you don’t necessarily have to stop at the local brewery for carb-tastic IPA, but I won’t judge you if you do.

In another research article by Hetlelid et al., they wanted to compare the levels of fat and carb oxidation levels between nine well-trained (WT) runners and nine recreationally-trained (RT) runners during a high-intensity interval training session (HIIT). There was no difference in diets amongst the participants in the study. The study found that the WT runners had a three times higher rate of fat oxidation than RT runners and increased performance with higher VO2 max. The author attributed the increased performance due to the higher rates of fat oxidation. These athletes were consuming a normal carb-ful diet, which makes me wonder what the difference would have been if they were fat adapted.  

So, let’s get down to why all this mumbo-jumbo is important to your next trip to the high country. Many outdoor activities that we enjoy in the summer like hiking, biking, climbing, etc. all require significant energy to supply for all day fun. Take climbing a 14’er, for example. You will most likely be climbing for several hours, depleting your energy stores as you climb being on a high carb diet. You have to stop, refuel, start up climbing, stop and repeat. As a fat adapted climber, you could sail past your carb-comrades with ease, not depleting your glycogen stores all day, all while burning some of that winter Christmas cookie belly in the process. As we examined the two research articles, we also found that higher fat oxidation could mean higher VO2 max levels.

What does this mean for your next trip to high altitude?

That’s right, better usage of the less available oxygen in the high country and improving oxygen delivery throughout the body. If you want to be the best Balliger you can be on the mountains this summer, rethink your energy supply and consider life in the fat lane! 

So, here are some personal tips to becoming fat adapted:

-Give your body at least 3 weeks to become adapted before any highly strenuous activity, like climbing a 14’er

-Hydrate, hydrate, hydrate with water, and balance it with electrolytes

-Consult with your physician before drastically changing your diet

-Choose foods high in natural fats (eggs, nuts, olive oils, avocados, meat, fish, dairy) and stay away from unhealthy trans fats

-Intermittent fasting can help you transition into ketosis faster (12-16 hrs)

 

References

Hetlelid, K. J., Plews, D. J., Herold, E., Laursen, P. B., & Seiler, S. (2015). Rethinking the role of fat oxidation: Substrate utilisation during high-intensity interval training in well-trained and recreationally trained runners. BMJ Open Sport & Exercise Medicine, 1(1). doi:10.1136/bmjsem-2015-000047

Volek, J. S., Freidenreich, D. J., Saenz, C., Kunces, L. J., Creighton, B. C., Bartley, J. M., . . . Phinney, S. D. (2016). Metabolic characteristics of keto-adapted ultra-endurance runners. Metabolism, 65(3), 100-110. doi:10.1016/j.metabol.2015.10.028

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High Altitude, Medicine

Altitude research partnership with University of Heidelberg and University of California in San Diego

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Two of the most prominent centers for altitude research in the world are University of Heidelberg, led by Peter Bartsch MD and                                                                                                               University of California in San Diego, with John West MD.

Dr Christine Ebert-Santos met with five of their affiliated researchers while in San Diego where she presented her case on                                                                                                                    trauma and HAPE at the American Thoracic Society conference.

They are interested in partnering with Ebert Family Clinic for a study related

to the genetics of high altitude, using our area as an intermediate altitude location.

Photo of Dr. Chris with UCSD staff  Tatum Simonson PhD, facing, Jeremy Orr MD, behind her,

Jeremy Sieker MD PhD candidate from Colorado, and University of Heidelberg staff  Heimo Mairbaurl PhD and Christina Eichstaedt PhD

Information and discussion for visitors and residents at high elevations.