Use awe instead of glucose

Energy conservation is a fundamental concern of every alpinist, trail runner, climber, and skier. How your body uses glucose – and how much it uses – is a major determining factor in whether you succeed in your objective and return safely. On a more mundane level, bonking or simply being too low on glucose will reduce your enjoyment of being active in the mountains.

For this reason, we train our body to stay fat-burning for longer before it switches to using primarily glucose. The higher the effort level at which we can stay in lipolysis (the metabolism of fats for fuel in the presence of oxygen) before switching to glycolysis (the metabolism of glucose for fuel in the absence of oxygen), the faster we can go, for longer. In the mountains, speed without haste = safety.

The brain runs on glucose

Most critical is the supply of glucose to the brain. Your central nervous system (CNS), which includes the brain and motor nerves, sends the signals to your muscles to contract. As Scott Johnson and Steve House write in Training for the New Alpinism, “The CNS seems to be the ultimate driver and limiter of human performance. It does this through the motor nerves that control the muscles, and are responsible for propelling you up the mountain.” [1] In the brain, glucose provides the energy for neurotransmission. In short: when the brain doesn’t get enough glucose, your muscles won’t work well.

A resting awake brain uses almost as much oxygen as glucose (ratio ca. 5.5:5.8), but when the brain is active, whether in mental activity or physical activity (or both!), it starts to use more glucose and less oxygen. This has obvious implications for high-altitude activities – there is a large rise in glycolysis during hypoxia (insufficient oxygen) or anoxia (no oxygen).

This increased rate of glucose utilisation is highest when we’re thinking. Models of energy use in the brain suggest that “a considerably larger amount of energy is spent in the grey matter compared to the white matter.” [2] The grey matter is what we use for decision making and other executive functions, and the brain’s energy use is highest in neuronal computation (generally understood to mean cognition) and information processing. This is why hard climbing moves and routes get easier the more you do them – because you don’t have to think as much or as hard, and it’s why your internal power meter will start to drop when you’re running a route you know well and you suddenly encounter an unexpected obstacle or deviation. Having to suddenly think about the variation in the route results in a sudden uptick in glucose use by the brain.

Because the brain is the central controller of everything to do with the body and itself, and because it is reliant on other parts and systems of the body to send it nutrients, it is not surprising that the brain has ultimate control over how those nutrients are distributed. The brain is constantly working via the CNS (specifically, the hypothalamus) to maintain systemic energy balance and glucose homeostasis.

Stress increases glucose use

Mountain athletes contend with many stressors – physical effort and fatigue, mental effort and fatigue, dehydration, inadequate nutrition (fuelling), gastrointestinal distress, loneliness, insufficient and/or inadequate sleep, overwhelm, doubt, uncertainty, fear, pain, injury – and these stressors exacerbate each other. When you’re sleep-deprived, for instance, your sensitivity to physical pain increases, as does your emotional reactivity: everything hurts more and seems worse.

When we experience stress, the body releases glucocorticoids (steroid hormones, such as cortisol, that are produced by the adrenals) and catecholamines (neurotransmitters and hormones such as adrenaline and dopamine). To cope with the increasing energy demands of the body, the glucocorticoids induce hypermetabolism. In other words, when you’re stressed, your metabolism speeds up. So, to conserve energy, you need to reduce your body’s stress response.

Use awe instead of glucose

Simply by being in the mountain environment, you are already biasing activation of the parasympathetic nervous system. Our body responds in positive ways physiologically to the natural world. The sounds of water can reduce the fight-or-flight cardiovascular response, blood pressure, cortisol, and inflammation; certain scents calm our stress-related physiology; and many plants emit phytocides, chemical compounds that reduce blood pressure and boost immune function.

But the activities we perform in the mountains and the risk involved create sometimes extremely high levels of stress, which eats up glucose.

A moment of awe can immediately generate a calming effect, while simultaneously energising the sympathetic nervous system to promote action without the aggression or anxiety of ‘fight or flight’. It also opens your mind, so you collect information on the actual situation and conditions, rather than the constricted or catastrophised view of the stressed mind.

As your physiology shifts in these ways, glucose use drops. And as your thinking mind calms down, it also demands less glucose. As a further benefit, experiencing awe takes us outside of ourselves and promotes prosocial behaviour.

Accessing awe periodically throughout your activity could reduce your overall need for glucose, enable you to make clearer decisions, and improve your relations with your climbing partners.

Try it out, and tell us how it goes.