Leading research at the top of the world

Sunset over the village of Khunde, Nepal. Mount Ama Dablam (far left) and Mount Thamserku (middle) are shown in the background. Photo credit: Craig Steinback

Craig Steinback and Margie Davenport — both professors and researchers in the Faculty of Kinesiology, Sport, and Recreation — never imagined their research would take them to the highest peaks on Earth. But a surprising request eight years ago set the stage for groundbreaking studies on pregnancy at high altitude.

It began when a colleague in Nepal had a pregnant guide on his team and was concerned for her health and safety. With limited research in this area, he contacted Steinback — whose area of research is environmental physiology, and Davenport — an exercise physiologist who leads the Program for Pregnancy and Postpartum Health and studies the effect of physical activity during pregnancy.

Together, they monitored the individual, who was of Sherpa descent, and discovered that she was exercising around 300 minutes per day — double the weekly recommended amount of activity in Canada — with no ill effects. “That was our first insight that physical activity may be fine for certain people at high altitude,” says Davenport. 

A porter transports equipment between villages. Photo: Craig Steinback

Conducting vascular assessments at the lab in Khunde. Photo: Craig Steinback

The journey to Nepal

After navigating complex government permissions and regulations, the research team travelled to Nepal in May 2023 and May 2024 to conduct assessments on participants in Kathmandu and the Himalayan village of Khunde near Mount Everest, at an elevation of 3,840 metres. For comparison, Banff, Alberta — the highest town in Canada — sits at an elevation of 1,383 metres. 

To reach Nepal, the team flew to Kathmandu and then on to the Tenzing-Hillary Airport in Lukla, rated the most dangerous airport in the world due to perilous winds, fog and its short, single runway that runs into the side of a mountain on one end and drops into a steeply angled valley on the other.

Travelling to Khunde, the team needed to ascend slowly. “It’s all designed to make sure that as you go up, even if you aren’t feeling well, you have time to recover before moving up to higher altitudes,” says Steinback, who didn’t suffer from altitude sickness but did find himself breathing harder, had a mild headache and felt a bit “foggy.”  

Local Sherpa guides and physicians were instrumental in recruiting participants from remote, sparsely populated regions and providing language and cultural translation. The guides also procured accommodation and transported lab equipment and personal packs to their destination by “yaks and backs.”

Research

“We have a lot of guidelines and recommendations about what you can, should and should not do during pregnancy and one of them is that you shouldn’t exercise above 2,500 metres,” says Davenport. “But this [specific recommendation] isn’t based on empirical evidence or research; it’s just based on expert opinion.”

To address a lack of research in this area, Davenport and Steinback’s study examined cardiovascular, respiratory and metabolic function in pregnant and non-pregnant women at high altitude, both at rest and during exercise — ranging from short bursts of vigorous exertion to intense, daily trekking. The goal of the study was to provide a comprehensive assessment of the combined stress of pregnancy and altitude. The results will be compared with control groups of similar participants who are living at low altitude.

The team, including a physician and ultrasonographer, closely monitored participants’ heart rate and blood pressure, took blood samples, scanned the mothers’ hearts and looked at fetal heart rate and blood flow to the babies. Then they did an exercise test that can be repeated on individuals in Canada or elsewhere. Participants then wore accelerometry monitors — small matchbook-sized devices — around their waists to measure their activity levels throughout the week and answered questionnaires about their daily activities.

Next steps

“This research increases our understanding of maternal and fetal health and well-being in extreme environments,” says Davenport. The next steps are to evaluate individuals who travel from lower altitudes to higher altitudes when pregnant, to see how mother and baby respond to these acute transient exposures. That information will help shape exercise guidelines for pregnant women who visit the mountains for recreation, for example.

Steinback is interested in how the body responds and adapts to environments, activities and conditions associated with reduced oxygen availability, or hypoxia.

“As you go higher in altitude, the barometric pressure generally drops. With every breath, you take in less oxygen because there’s less oxygen in volume,” explains Steinback. Some people may take more breaths and others may have blood that can hold more oxygen. These and other adaptations likely underpin why some individuals get sick at high altitudes and some don’t.

“These unique populations at altitude are genetically adapted to survive. So that gives us some insight into what traits make people successful when they’re hypoxic,” says Steinback. “When we understand certain traits that might make individuals more or less susceptible to poor outcomes when they’re hypoxic, this might help guide the development of personalized medical treatments for issues such as heart failure or lung diseases.”

“It’s important to recognize the importance of global health and collaborating with other clinicians and researchers outside our normal environments,” adds Davenport. “One of the most rewarding parts of the research was helping local women with their overall health. They don’t get their blood pressure or blood sugars checked regularly. The physician and ultrasonographer with us identified underlying health conditions in some participants that needed followup. They wouldn’t have known about it otherwise.”