Tag Archives: hypoxia

Friends in high places: Researchers go global for answers at high altitude (Part 1)

By Alexandra Williams, @AlexM_Williams

Global Research Expedition on Altitude Related Chronic Health (or Global REACH) is an international collaboration of academics and physicians from 14 institutions across Canada, the UK, the US, Peru and Nepal. While the “Global REACH” title is relatively new, its leaders have conducted a multitude of expeditions over the last decade to Nepal’s Himalaya, California’s White Mountains and now Peru’s Andes. With a collective interest in heart, lung and vascular health and altitude medicine, Global REACH’s collaborations ultimately aim to understand how the human body adapts, or maladapts, chronically to the low oxygen environments of earth’s highest altitudes.

I am writing this from 4,300 m, at the Laboratorio de Cerro de Pasco and Institutio de Investigaciones de la Altura in Peru. Our team of over 40 researchers, trainees, principal investigators and physicians are currently conducting approximately 20 studies examining heart, lung and brain physiology in lowlanders (us) and Andean highlanders with and without chronic mountain sickness.


Example of a centrifuged blood sample from an Andean participant with chronic mountain sickness. A normal, healthy lowlander’s hematocrit (i.e. fraction of red cells in the blood) is ~40%; several Andean participants including this one had hematocrit values of 75-80%.

This series of blogs, however, does not intend to outline our experiments or specific scientific findings (which was described in a recent issue of Physiology News). Instead, you will get a raw, behind-the-scenes look at what transpires on these expeditions: the challenges we face, the experiences we gain, and most importantly the team values that drive the success of these international collaborations.

30 June 2018: Day 1 at altitude

Yesterday, the last of three groups of the Global REACH team drove from sea level in Lima up to 4,300 m in Cerro de Pasco, Peru. Amongst the team, some individuals are feeling “okay” (say, a rating of 7/10), while others have been in bed with splitting headaches for more than 24 hours. We would later discover that one, in fact, had a bout of pneumonia. Nevertheless, one thing remains constant across the team – the excitement. It is palpable. Seven lab bays are set up, participants are being scheduled in, the equipment is (mostly) accounted for and working. Data collection has already begun today, and our first Andean participants are coming in tomorrow morning. This is what we came for, and we’re ready for the fun to begin.

For those who haven’t experienced the thin air of Earth’s highest mountain ranges, a 7-hour jump from sea level to over 4,300 m altitude is significant, one which often leaves individuals feeling much worse than “not great.” Yet, with advanced knowledge of the side effects of altitude and hypoxic exposure, Global REACH members have joined forces to answer a plethora of physiological questions. For many, this will mark more than four expeditions to high altitude, a select few even in the double digits. In the first few days, most – including our team leaders – will have headaches, nausea, sleep disturbances and apnoeas. The inter-individual variability of these symptoms is quite high, as a select few may feel fine, most will feel some magnitude and combination of the list, and others will be periodically out of commission.


Performing a carbon monoxide rebeathe test to measure red cell volume and total blood volume with an Andean participant in Cerro de Pasco. This method is technically challenging, and is made more difficult with a significant language barrier.

So, why do we do it? Why do we involve ourselves with the potential suffering at altitude and any additional risks (i.e. transport, illness) kindred to these trips? From my experience, three fundamental elements outweigh the risks and define the success of expeditions and collaborations like Global REACH: the science, the experience, and the team.


1 July 2018: Day 2 at altitude

“MAS FUERTE, MAS FUERTE, yeah Johnny!” Johnny, our first Andean participant is laying on the bed of testing Bay 1, currently practising a handgrip protocol for a vascular study. Johnny already has a venous catheter placed in his forearm and will be shuttled through a screening circuit: ultrasound imaging (cardiac, ocular and vascular), a maximal exercise test and assessment of total blood volume. Our Spanish skills are currently dismal, but we’re managing to compliment the amazing work of our translators to collect a large cardiovascular dataset on approximately 50 Andean participants.

3 July 2018: Day 4 at altitude

Four of us are working in the bloods room to measure total blood volume, hematocrit and viscosity. We knew from previous reports that Andeans would have augmented total blood volumes and hematocrit levels compared to us lowlanders but seeing those bloods ourselves was staggering. ‘A hematocrit of SEVENTY-EIGHT per cent!’ a colleague yelled, astounded. For reference, a lowlander’s normal hematocrit is ~40%. (Fig. 1) An undeniable passion for physiology underpins collaborations like Global REACH.

The energy amongst the group drives impressive productivity and allows us to complete multiple studies in relatively restricted time periods. During the 2016 Nepal Expedition our team conducted 18 major studies, including a total of 335 study sessions in just three weeks at 5,050 m (further to multiple sea level and ascent testing sessions). This high-density data collection is relatively uncommon outside of field work and is only made possible by the vast breadth of technical fluency, specific expertise and research experience amongst the team. The expeditions allow us to not only answer our current questions but further breed a multitude of ideas for future study.


‘We could answer that one next, Ethiopia 2020? Another Nepal expedition?’ Of course, these expeditions allow us as trainees and investigators to be productive, and to present and publish high-quality data and exciting findings. They strongly contribute to our development and career progression in academia. But what is undoubtedly most important is the greater aim of Global REACH: to understand altitude health on a ‘global’ scale. This collaboration and research ultimately aims to understand why chronic mountain sickness occurs, how different high-altitude communities have adapted (or maladapted) to low oxygen, and what might ultimately be done to improve the health of individuals exposed to acute or chronic hypoxia.

Stay tuned for Part 2 next week, or read the full article in its original version in Physiology News magazine.

Prize Lecture Memoria – Michael de Burgh Daly

DALY, Michael de Burgh ,Barts,London 1978 (1. 19-19A)Michael de Burgh Daly (1922 –2002) was an English physiologist and son of the renowned physiologist and Royal Society Fellow; Ivan de Burgh Daly. Daly was educated at Gonville and Caius College, Cambridge and St Bartholomew’s Hospital, London in his clinical studies. In 1947 he became a house physician at St Bart’s and went on to become an Assistant Lecturer (1948) and then Lecturer (1950) at University College London. In 1958, at the age of just 36, he was appointed to the Chair of Physiology at Bart’s Medical School and Head of Department – a position he held until his retirement in 1984 at the age of 62. He then moved to the Royal Free Hospital School of Medicine, to the Department of Physiology for the remainder of his life. He worked principally on peripheral arterial chemoreceptors and respiratory-cardiovascular Integration, especially with reference to the effects of hypoxia and apnoea. His work included detailed studies of diving. His Physiological Society monograph in 1997 is rightly celebrated. Michael de Burgh Daly died on 1 March 2002 aged 79. The Physiological Society established the Michael de Burgh Daly Prize Lecture in 2002; this biennial lecture is given in memory of the distinguished physiologist, with input from the Cardiovascular & Respiratory Physiology Theme Lead.

Researcher in the Spotlight April 2016


Dr Melitta McNarry is a Senior Lecturer, College of Engineering at Swansea University and specialises in cardiorespiratory fitness across the health, fitness and lifespan with a particular interest in paediatric populations. 



What is your research about?

My recent work has focused on the development of non-pharmacological intervention strategies, such as inspiratory muscle training and high intensity interval training, for people with asthma and cystic fibrosis. I specialise in cardiorespiratory fitness across the health, fitness and lifespan with a particular interest in paediatric populations. Recent work has focused on the development of non-pharmacological intervention strategies, such as inspiratory muscle training and high intensity interval training, for people with asthma and cystic fibrosis.

Furthermore, I am interested in the role of pulmonary rehabilitation for patients with respiratory disease, especially Idiopathic Pulmonary Fibrosis, and the potential modifications that can be made to traditional strategies to optimise the outcome for the patients. With regards to such patient populations, I have recently begun to investigate the relationship between rheological parameters, namely blood clotting, hypoxia and exercise. Finally, following on from my PhD work, I continue to investigate the interaction between training and maturity on the bioenergetics responses of children and adolescents.

How did you come to be working in this field and was this something you always wanted to do?

While studying for my Biology degree at the University of Exeter, I realised that I was more interested in human physiology than plants or microbiology, so when a conversation at training one evening led to the offer to complete my dissertation in the School of Sport and Health Sciences I jumped at it! Little did I know this was just the start as following the success of my undergraduate dissertation I was offered a scholarship to complete a PhD at the University of Exeter. Whilst not something that I planned to do when I was “older”, I have been brought up in an academic family so it wasn’t a foreign concept when the opportunity arose.

Why is your work important?

My work unites theory with application, aiming to provide real-world solutions to pathophysiological conditions that do not revolve around pharmacological interventions. I therefore believe that my work has the potential to improve patients’ quality of life on a daily basis – even if this is only one patient I would count this as an important impact from my work.

Do you think your work can make a difference?

I think my work has the potential to make a difference on the individual patient level, improving the functional capabilities and enhancing their quality of life.

What does a typical day involve?

I would say that the joy of this job is that there is no such thing as a typical day, every day differs with the only common features being that they are generally too busy and that I never get what I planned to do that day done but a thousand other things instead! Nonetheless, a ‘typical’ day involves getting to work early in the morning to try and fight a rising tide of emails before numerous meetings with everyone from undergraduates to internationally renowned professors. This is then combined with giving lectures and running lab sessions for our undergraduates and, on the good days, with conducting testing to advance our studies and research.

What do you enjoy most in your job?

I enjoy working with children and patients in the lab and field, interacting with them and seeing research translated into real-life. The mundane (aka, admin-related) elements of the job often make you wonder why you continue working such hours but the rare moments you get to run physiological tests with participants reminds you why you started.

What do enjoy the least?

The requirement to be a jack-of-all-trades from teaching to research to administration, resulting in you being a master of none.

Tell us something about you that might surprise us…

I am not formally trained in Sport Science or Exercise Physiology! My undergraduate degree was in Biosciences.

What advice would you give to students/early career researchers?

Working hard is more important than intelligence, but sometimes things will happen at their own pace and nothing you can do will speed it up; be patient as if it is meant to be, it will be.

Researcher in the Spotlight March 2016


Hans-Christer Holmberg is Professor of Sport Science at the Department of Health Sciences, Mid Sweden University, Sweden. He is also director for Research and Development at the Swedish Olympic Committee and the Swedish Winter Sports Research Centre. His research has mainly focused on cross-country and alpine skiing.

Hans-Christer will give a plenary lecture at our BBEP meeting, 6-8 March 2016 in Nottingham, UK on Monday 7 March from 18.00 GMT. You can watch the live steam here.
Physiological limits to human performance: insight from the elite cross-country skier

What is your research about?

My research mainly focuses on cross-country and alpine skiing, and uses an integrative physiological and biomechanical approach. However, we also study other sports (such as cycling, running, swimming and rowing) and more general topics such as the effects of different types of endurance training and environmental factors (hyperoxia/hypoxia) on performance. Because of my position on the Swedish Olympic Committee, I am able to coordinate sport scientists from a wide range of disciplines and direct their expertise to helping elite athletes.

How did you come to be working in this field and was this something you always wanted to do?

I have always been interested in sport and competed in several sports myself. My educational background and work experience, before I started my research, was working with elite athletes as a chiropractor and as a coach for world-class endurance athletes (in cross-country skiing and kayaking). It was through this that I met Professor Bengt Saltin. After many hours of interesting discussions, he said to me, “HC, you ask so many interesting questions – you should be a sports science researcher”. Prof. Saltin’s knowledge and enthusiasm inspired me to change course and, after studying at the Swedish School of Sport and Health Sciences, I got my Ph.D. in Medical Science from the Karolinska Institute in Stockholm. Overall, my great personal interest in sports has stimulated numerous ideas that we have applied to help athletes and enhance performance.

Why is your work important?

My main aim has been to contribute to the development of cross-country skiing as a sport. In parallel, I have also exploited cross-country skiing as a unique experimental model that allows insights about exercise physiology and locomotion/kinesiology. Cross-country skiing uniquely has numerous techniques and sub-techniques (classic vs. skating, diagonal stride vs. double poling etc.) that differentially involve the upper and lower-body, and all at or above the extremes of our aerobic capacities. Our scientific work involves extensive international collaboration and I am proud that the Swedish Winter Sports Research Centre has become a hub, not only for researchers interested in winter and snow sports, but also for physiologists who study basic mechanisms using cross-country skiing as a model system.

Do you think your work can make a difference?

Absolutely. Our work has made significant contributions to developing the sport and had an impact on general practice/training, as well as helping to improve performance. Cross-country skiing is a popular recreational sport in many parts of the world and some of our research has also raised public awareness of the many positive training adaptations and health effects of this type of exercise. Scientifically, our studies have hopefully also contributed to enhancing the general understanding of exercise physiology. Additionally, our approach of combining physiological and biomechanical measurements has inspired other sport scientists to perform integrated multidisciplinary studies.

What does a typical day involve?

I almost always begin my day with some exercise, which varies with the seasons. For example, this morning I cross-country skied for 90 minutes on trails that lead from my home. In the summer, I enjoy running on the special soil called muskeg that we have in Sweden.

My work involves many different things. As a researcher, I write scientific articles, meet with other researchers and students, supervise Ph.D. and postdoctoral students, organize projects, analyse data, apply for grants, visit collaborating international research groups and make presentations at conferences.

As a Director for R&D at the Swedish Olympic Committee, I meet with coaches and athletes, initiate and lead projects, identify trends and topics of interest for coaches/athletes that could possibly impact performance; supervise support staff and participate in training camps and events/competitions. I am also involved in planning for upcoming Olympics (Rio 2016 and PyeongChang 2018) and meetings with the Olympic organizations from other nations around the world.

What do you enjoy most in your job?

I enjoy trying to find solutions and transferring knowledge to athletes, coaches and the research community. As an entrepreneur, I love developing environments and coaching people, initiating and finalizing a range of projects and having an impact on sport performance. My job allows a high level of flexibility and the great variety of tasks gives me energy. I am never bored, there are so many challenges.

What do enjoy the least?

Meaningless meetings.

Tell us something about you that might surprise us…

Well, I like going out in the mountains around where I live in Åre to blow my birch trumpet (näverlur) and I’m very interested in wine, especially from the European regions around the 45th parallel north. 

What advice would you give to students/early career researchers?

Don’t think too much about your goals. Instead, enjoy your work and the results will come.

See challenges as something positive and make the most of them.

Researcher in the Spotlight February 2016

Joyner 2010 001_Fotor

Dr Michael J. Joyner, M.D. is interested in how humans respond to various forms of physical and mental stress during activities such as exercise, hypoxia, standing up and blood loss. Dr Joyner will give a plenary lecture at our BBEP meeting, 6-8 March 2016 in Nottingham, UK on ‘Physiological limits to exercise performance: Influence of gender’. You can watch the live steam here.


What is your research about? 

I do integrative physiology studies in humans. My main interests are exercise physiology, blood pressure regulation, and regulation of metabolism. I am also interested in what world records in sport can tell us about physiology and also how the interplay between reductionism and holism in research informs science policy. 

How did you come to be working in this field and was this something you always wanted to do?

I started in the late 1970s as a human subject in a study on the lactate threshold and distance running performance, and was hooked from day 1. A career focused on physiology research hit me like a thunderbolt at age 19. Until then I had been an indifferent student. The investigators in that original study were extremely encouraging and set the stage for what has followed.

Why is your work important? 

The work on exercise largely focuses on the regulation of skeletal muscle blood flow. The mechanisms that evoke the massive vasodilation during exercise are only now beginning to be understood and this has been one of the great intellectual puzzles in biology over the last 150 or so years. The work on blood pressure has shown that women and men regulate blood pressure very differently and that especially for women things change dramatically with age. This work has relevance for the understanding, prevention and treatment of hypertension. My interest in blood pressure also extends to clinical monitoring (I am an anaesthesiologist) and how it can be refined to improve patient care. The studies on metabolic regulation focus on the non-oxygen sensing role of the carotid bodies and how they might contribute to things like the diabetes frequently seen in patients with sleep apnoea. The world record stuff is just plain fun and my interest in science policy is about trying to move the scientific and medical communities away from their current DNA centric world view.

Do you think your work can make a difference?  

Yes, there is a translational element of almost everything my lab does and I like to think we can help link basic science observations to the whole human. By understanding physiological regulation in humans, we can then see how it goes off the rails in disease states and think about how to intervene to essentially restore homeostasis.

What does a typical day involve? 

I get up early around 5AM and answer my e-mail and read the New York Times, at about 6 I exercise for 30-60 minutes and then head to St Marys Hospital which is part of the Mayo Clinic. My house is only about 2km from the hospital and usually I ride my bike. Four days per week, I am in the lab working with my staff and fellows. I am lucky to still participate in the data collection in our invasive studies but beyond that it is a lot of editing, discussing ideas, generating proposals etc. Over the years, the Fellows in the lab have been superb and almost all now run independent programs at “Research” Universities. My technical staff and research nurses have all been with me for years and the team is very strong.

What do you enjoy most in your job? 

Almost everything! The interactions and chance really to learn from the students and fellows is the gift that keeps giving.

What do enjoy the least?

The compliance bureaucracy can get a little convoluted and frustrating at times. 

Tell us something about you that might surprise us…

In high school I was an all-state French Horn player.

What advice would you give to students/early career researchers? 

Do what you are interested in and don’t buy into the idea that a fulfilling life is a linear engineering exercise. It is nine-ring circus.