The Upside of Anxiety: Rethinking Performance Nerves.

Why anxiety isn't always the enemy and ways to manage it when it is.

Imagine a swimmer at the starting blocks, heart pounding and stomach twisting in knots. The blocks feel scary, like a tiny cliff to jump off while everyone’s watching. Even before the race starts, their hands are shaking, muscles are tight, and all that anxiety makes them feel like giving up before they even start.

Experiences like this are common, and feeling nervous is normal. It can even be helpful, though it certainly feels awful in the moment (just ask this fictional swimmer). So you might be wondering, how can something that feels so bad possibly be useful? To answer that, let me introduce you to your autonomic nervous system.

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The Autonomic (Automatic) Nervous System (ANS)

As the name implies, it’s responsible for our body’s automatic and involuntary processes. You can’t consciously tell your heart to speed up during a sprint or slow down in an ice bath, it just happens. There are two subdivisions within the autonomic nervous system (ANS) that controls these responses.

First, we have the sympathetic nervous system (SNS). The SNS mobilizes energy during stressful situations (your fight-flight-or-freeze response, if you will). For example, when you’re in danger, the air passages in your lungs expand to help you breathe better (also known as bronchodilation; that’s a surprise tool that will help us later).

The opposite effect is controlled by the parasympathetic nervous system (PNS). The PNS calms the body and conserves energy. Using our previous example, once you’re out of danger, the air passages narrow and, to compensate for the decreased real estate, your breathing slows down.

Struggling to keep it straight? Remember:

Sympathetic nervous system = survival.

Parasympathetic nervous system = peace.

Feeling anxious before a competition is our body’s way of preparing us for a stressful event. Now imagine that same response, but instead of stepping onto the blocks, you’re stepping out of an aircraft at 1,600 feet. That was the case for a group of 38 Spanish soldiers in the airborne brigade.

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Spanish Soldiers

A group of researchers were interested in studying how the psychological and physiological aspects of the stress response impacted military performance. They hypothesized that high anxiety would be associated with a strong physiological response (e.g., increased heart rate, rapid breathing, muscle tension). They also suggested that these heightened responses could hurt performance, leading to outcomes such as traumatic brain injuries and trouble with fine motor skills (e.g., manipulating weaponry, using communication devices.

The researchers measured stress, anxiety, and other physiological factors in the soldiers before a 500m parachute jump (for reference, that’s roughly the height of the Eiffel tower). Contrary to their expectations, they found that the soldiers showed greater situational awareness, faster visual processing, improved leg strength, and better motor skills (all indicators of positive performance outcomes) after the jump (despite their anxiety levels).

The major takeaway from this study is that everything has a purpose, even stress and anxiety. While the feeling is unpleasant, it’s you who determines the outcome, not your fear. This group of soldiers experienced positive results despite their anxiety, but as you might have guessed, that isn’t always the case.

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PNS vs SNS: Who's in Control?

We’ve talked about anxiety being useful, but sometimes it goes too far. Going back to our nervous system, imagine your parasympathetic nervous system (peace) and sympathetic nervous system (survival) are in a car. The PNS is driving, and the SNS is in the passenger seat. Out of nowhere, a snow squall hits (if you’ve ever experienced one, you know how stressful it is). Your SNS takes the wheel to help you navigate the storm, but it overcorrects, and suddenly the car is out of control. This is performance anxiety.

Your SNS isn’t inherently bad— it’s just an automatic protective response. But just because the SNS has the wheel doesn’t mean the PNS can’t take it back. This is the purpose of relaxation techniques. The PNS is capable of grabbing the wheel at any time (the same way you can try breathing techniques you find online without a mental performance consultant). But techniques and mental performance training the PNS how to safely grab the wheel and navigate the storm.

Psychological stress often arises when people feel they have little control over a situation or lack experience. So let’s give you a tool to take back control, along with the practice needed to weather the performance anxiety storm.

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How to Make Anxiety your Ally

Remember the surprise tool we mentioned (your lungs expanding to help you breath in danger)? Now we’ll explore how we can intentionally use breathing to calm ourselves down.

Ratio breathing is a relaxation technique that engages the parasympathetic nervous system by regulating your breath. The most important aspect of ratio breathing is controlling the length of your breaths and making sure your exhale is always longer than your inhale. Long exhales trigger your parasympathetic nervous system to lower your heart rate.

Try it out: Use a beginner-friendly breathing pattern: slowly inhale for two counts, then exhale for four. Repeat this pattern (2:4) until you feel calm (stop immediately if you feel lightheaded or experience any pain).

Ratio breathing is just one tool to help relax and calm the body. Different people and situations call for different mental performance skills. Performance anxiety varies widely, and it can feel difficult to handle alone. But it’s important to remember that you control your sport experience and have resources to support you. So the next time you’re nervous on the blocks or scared before a match, try ratio breathing—and remember, it’s never too late to start your mental performance journey.

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Thanks for Reading!

Ever wonder why professional athletes have the same pregame routine? Want to create a New Year’s Resolution that’ll stick? Mac's Performance Hub is the place for all your mental performance needs. Visit services to start your mental performance journey or subscribe to my substack for blog updates.

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Learn More

Clemente-Sáurez, V. J., Robles-Peréz, J. J., & Fernández-Lucas, J. (2016). Psycho-physiological response in an automatic parachute jump. Journal of Sports Sciences, 19(1), 1872-1878. https://doi.org/10.1080/02640414.2016.1240878

Fekete, T., Pitowsky, I., Grinvald, A., & Omer, D. B. (2009). Arousal increases the representational capacity of cortical tissue. Journal of Computational Neuroscience, 27(3), 211–227. https://doi.org/10.1007/s10827-009-0138-6

Matsumura, S., Watanabe, K., Saijo, N., Ooishi, Y., Kimura, T., & Kashino, M. (2021). Positive relationship between precompetitive sympathetic predominance and competitive performance in elite extreme sports athletes. Frontiers in Sports Act Living, 3(712439). https://doi.org/10.3389/fspor.2021.712439

Myers, D. G., & DeWall, C. N. (2025). Exploring psychology (13^th ed.). Worth Publishers.