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By Johns Hopkins Medicine
What makes Olympians the very best at what they do — even in cold, slippery or icy conditions?
Scientists at Johns Hopkins Medicine tell us about the underlying biological processes that help these elite winter athletes excel in their sport and keep their head in the game.
Members of the media who would like to hear more from these scientists should contact Alexandria Carolan (acarola1@jhmi.edu) or Vanessa Wasta (wasta@jhmi.edu).
Skeletal Muscle Mitochondria and Endurance
- How do Olympic athletes sustain high-intensity muscle work for the duration of a race?
- Are the mitochondria of elite athletes better at getting oxygen and nutrients?
Cross-country skiing, long-track speed skating and ski mountaineering (making its Olympic debut in Milan Cortina 2026), all require incredible cardio and muscular endurance. What happens inside the muscles of elite athletes that allows them to perform continuous, high-intensity work?
Physiologist Anastasia Kralli, Ph.D., says that thanks to endurance training, athletes build extensive networks of mitochondria. Functioning as the cell’s powerhouses, mitochondria use nutrients and oxygen to produce adenosine triphosphate (ATP) — the energy currency that supports muscle contraction. While we can all respond to endurance training by building more and better skeletal muscle mitochondria, elite athletes differentiate themselves by attaining a significantly higher number of mitochondria — with increased capacity to burn fuel — than even well-trained recreational athletes. Endurance training also leads to other muscle adaptations that enable high performance, including the ability for muscles to take up, store and metabolize nutrients, as well as an increase in the number of blood vessels that improve oxygen and nutrient supply, Kralli says.
Kralli studies mechanisms that enable muscle adaptations in response to physical activity, including proteins that direct endurance-induced muscle mitochondria to position themselves next to capillaries. Better access to oxygen and nutrients, coupled with increased mitochondrial capacity to use these substrates for making ATP in muscles, can make all the difference for a high-performing athlete, she says.
When It’s Time to Put on the Training Jacket
- Are winter athletes better at adapting to the cold?
- How do we regulate our body heat in freezing temperatures?
As temperatures dip below freezing, two areas of our bodies help to regulate our response, or the response of a winter athlete: peripheral tissues such as our skin and a structure at the base of our brain known as the hypothalamus, says sensory neurobiologist Michael Caterina, M.D., Ph.D.
The decision to layer up for a winter sport has to do with getting our body temperature back to the level the hypothalamus is trying to maintain, Caterina says. If it’s cold out, blood vessels in our skin constrict to limit heat loss, hair may stand up, and we may shiver, he says. Another way we may derive heat is “non-shivering thermogenesis,” through which the body warms up without shivering using “brown fat” or “beige fat” cells — mitochondria-rich cells that were once thought to be prevalent only in animals and human infants, but which also exist in human adults, Caterina says.
Some people may be better at warming up through non-shivering thermogenesis than others, Caterina says. People who are cold-acclimated, or grew up in cooler climates, may have accumulated more of this brown and beige fat, enabling certain athletes to perform better in frigid temperatures than others, he says.
‘Feeling’ Tired and Choking Under Pressure
- How do athletes push themselves out of their comfort zone?
- Why do some athletes choke under pressure?
With a global audience of nearly 2 billion watching their performance, Olympic athletes have a lot on their mind while going for gold in freezing temperatures. Using functional MRI to study the brain, biomedical engineer Vikram Chib, Ph.D., investigates incentives, rewards and behavior — and can pinpoint the areas of the brain that determine achievement.
How can an athlete push themselves past their limit? In National Institutes of Health-funded research, Chib has identified two areas of the brain that work together to react to (and possibly regulate) the brain when it’s “feeling” tired and either quits or continues to exert effort. That could explain how athletes persevere in extreme sports and temperatures.
Why do certain people choke under pressure? In high-stakes circumstances, people who are more likely to choke have spikes of activity in a deep part of the brain that encodes value. In MRI imaging, this area of the brain lights up more the larger the incentive, Chib says.
Building Internal Models
- What prevents figure skaters from getting dizzy?
- How do Olympic athletes recover from a mistake in their performance?
Figure skaters can spin at a rate of more than 300 times per minute — and they manage to do so without getting dizzy. Biomedical engineer Kathleen Cullen, Ph.D., can tell you why.
In National Institutes of Health-funded research, Cullen studies the vestibular and proprioceptive systems, which tell you how your head moves through space, and how your body is organized.
“Years of training allow the cerebellum — the brain’s center for movement and balance — to build internal models that automatically recalibrate how motion-related sensory signals are interpreted, so what would make most people dizzy no longer throws elite skaters off balance,” Cullen says.
Also thanks to these brain models, the snowboarder, figure skater and freestyle skier can adapt if a trick doesn’t go as planned.
If a figure skater loses their balance while attempting an axel or a lutz on the ice, specialized neurons in the cerebellum help to “update” the brain in real time, where they learn from unexpected sensory errors. The brain can automatically help these athletes reconfigure their expectations and move forward, Cullen says.
Information source: Johns Hopkins Medicine Newsroom
