{"id":49816,"date":"2019-04-26T08:16:44","date_gmt":"2019-04-26T15:16:44","guid":{"rendered":"https:\/\/www.rei.com\/blog\/?p=49816"},"modified":"2019-05-10T07:40:47","modified_gmt":"2019-05-10T14:40:47","slug":"this-race-tests-the-limits-of-human-endurance","status":"publish","type":"post","link":"https:\/\/www.rei.com\/blog\/news\/this-race-tests-the-limits-of-human-endurance","title":{"rendered":"This Race Tests the Limits of Human Endurance"},"content":{"rendered":"

When you race 430 miles across the Yukon, you learn a thing or two about yourself. In taking part in the<\/span> Montane Yukon Arctic Ultra<\/span><\/a> (MYAU) on four different occasions, 33-year-old Jessie Gladish has learned that she enjoys the challenge of making her way across the frozen terrain. She\u2019s also learned that it allows her a sense of freedom she can\u2019t find anywhere else. Scientists recognize this, too, and for the past four years, have studied the athletes who take on this beast of a race, and the impact its conditions and demands place on their bodies.<\/span><\/p>\n

\u201cI like the feeling of pushing past discomfort, reasonable pain, mental suffering, and physical suffering,\u201d Gladish said. \u201cI feel stronger and more confident. I like being alone and dependent on myself; I do my best work when I don’t have distractions or external pressures\/ideas\/thoughts.\u201d<\/span><\/p>\n

February marked the 16th year of the MYAU, which bills itself\u00a0as the world\u2019s coldest and toughest ultra. It follows the Yukon Quest Trail, one of the world\u2019s most difficult sled dog races and offers distances including a marathon, 100 miles, 300 miles, and every other year, the 430-mile option.Athletes cover the distance by fat-tire mountain bike, cross-country ski or by foot, with the help of snowshoes.<\/span><\/p>\n

This year, a total of 76 athletes participated in the events, 60 of them men and 16 women, representing 20 different countries. Gladish was one of 40 competing in the longest distance and one of 12 who finished.<\/span><\/p>\n

Grueling race conditions make the MYAU a prime environment for discovering what humans are physically capable of. For the fourth consecutive year, researchers studied participants throughout the race, monitoring their energy expenditure, body composition, sleep and heart-rate variability. The study was originally launched by<\/span> Mathias Steinach<\/span><\/a> of the Center for Space Medicine and Extreme Environments Berlin, but for the third year in a row,\u00a0<\/span>Robert Coker<\/span><\/a> with the Institute of Arctic Biology at the University of Alaska assisted.<\/span><\/p>\n

Coker is interested in learning how the human body can operate efficiently under such difficult conditions; he hopes the results may be applied to other harsh environments, as in space or military missions.<\/span><\/p>\n

\u201cInitially, I was interested to see whether lean tissue mass would be preserved under these challenging conditions,\u201d he said. Coker\u2019s early results suggest that human bodies can adapt rather quickly to manage extreme conditions. In 2017, for instance, he found that in spite of running at a 2,000 calorie per day deficit (they burned approximately 6,000 calories per day and ate only 4,000), the athletes were able to maintain their muscle mass.<\/span><\/p>\n

Made for research<\/strong><\/p>\n

In this latest study, Coker was focused on drilling down on <\/span>how much<\/span><\/i> food the athletes would need to consume during the race to perform at a high level in challenging environments.<\/span><\/p>\n

The cold and stress of the race through the Yukon has implications for astronauts in space, where food is readily available, but the conditions are taxing. \u201cWe are working to expand the bandwidth of astronaut capacity in space. How far we can go and how much we can do in space will be directly proportional to our ability to sustain our metabolic requirements,\u201d Coker said.<\/span><\/p>\n

This year marked Gladish\u2019s first year trying the race on cross-country skis; her previous three races were on foot (she completed the 430-mile distance twice and the 300-mile distance once). She finished out in twelve-and-a-half days, the only cross-country skier to reach the finish line.<\/span><\/p>\n

Also competing in the 430-mile event this year was 33-year-old Gillian Smith, a critical-care flight nurse who, like Gladish, lives in the Yukon. It was her second attempt at the full distance, having not finished last year due to health issues. She completed the 100-miler in 2016. \u201cI feel like I have an advantage because I live and train here,\u201d she said. \u201cI have a lot of experience with the weather and can practice layering my clothes and understand what freezes and what doesn\u2019t.\u201d<\/span><\/p>\n

Most competitors pull sleds weighing up to about 75 pounds in order to carry all their gear and be self-sufficient in any situation. There are checkpoints about every 50 kilometers along the route, and Smith said that amounts to encountering about one a day.<\/span><\/p>\n

\u201cI bivouacked by the lake one night and when I got up, there were fresh wolf tracks all around my camp … I just kept going and tried not to think about it.\u201d<\/span><\/p>\n

While there are numerous challenges for each athlete, Smith said it\u2019s the isolation that gets to her most. \u201cYou\u2019re out there by yourself and face a lot of stressful moments,\u201d she said. \u201cYou have to manage your fear.\u201d<\/span><\/p>\n

Even the most adept and confident, like Smith, have their moments. \u201cI bivouacked by the lake one night and when I got up, there were fresh wolf tracks all around my camp,\u201d she said. \u201cI just kept going and tried not to think about it.\u201d<\/span><\/p>\n

\"Athletes

Athletes make their way through the brutal conditions of the Montane Yukon Arctic Ultra.\u00a0(Photo Credit: Mark Kelly and MYAU)<\/p><\/div>\n

After the race, athletes receive the results of their own personal blood draws, which researchers take four times along the way. Both Gladish and Smith were among the 20 participants in the research this year, plus six individuals\u2014aid-station volunteers\u2014who served as sedentary controls, receiving testing at the same intervals as the athletes.<\/span><\/p>\n

Coker is unsure how the two groups will compare. Gladish wants to learn what she\u2019s doing to and for her body in these events. \u201cAm I pushing it too much?\u201d she wondered. \u201cDoes it make me healthier to do long distance racing, or not?\u201d<\/span><\/p>\n

While the 2019 research results aren\u2019t in yet, Coker said that both researchers and athletes can take away these key points from past results:<\/span><\/p>\n