The experience of stress can occur when anticipating an event or in the moment.

Stress experienced by athletes in competition triggers necessary biological, physiological and psychological responses in readiness to perform.

Why the body responds

Adaptive responses to stress occur through three systems:

Sympathetic Nervous System (SNS)

Functions to regulate the body's unconscious actions and prepares the body for physical activity. Enables the body to use energy appropriately to respond to stimuli.

Parasympathetic Nervous System (PNS)

Functions to regulate the body's unconscious actions and has a calming effect on many body functions. Active during periods of reduced energy expenditure.

Hypothalamic-Pituitary-Adrenal Axis (HPA axis)

Represents the interaction between the hypothalamus, pituitary gland and adrenal glands. A feedback loop that functions to maintain physiological homeostasis and mediates the effects of stress by regulating numerous physiological responses and processes.

Autonomic Nervous System

The SNS and PNS are the two components of the Autonomic Nervous System, which is responsible for regulating involuntary or automatic body functions, such as heartbeat, blood flow, breathing, and digestion.

HPA Axis

The HPA axis, is the interaction between the hypothalamus and pituitary gland just above the brainstem, and the adrenal glands on top of the kidneys. The HPA axis is responsible for producing a stress hormone cortisol.

How the body responds

Stress is quickly detected by the body which sends signals to the brain. The brain then produces a biochemical response which activates the SNS and the HPA axis, and releases biological analytes which trigger physiological responses in readiness for performance.

Biological

During a stress response the Sympathetic Nervous System and the HPA axis are activated, signalling biological analytes to flood the body.

Neurotransmitters like Neuropeptide-Y, Hormones such as Cortisol, Enzymes like Interleukin-6 and Catecholamines such as adrenaline are released.

Physiological

As the burst of biological analytes floods the body during a stress response, this triggers physiological responses, creating energy resources.

Physiological responses can include:

• increase in heart rate to pump more blood and oxygen to the muscles
• feeling shaky as adrenaline is getting the muscles ready to activate for a faster reaction time
• increased sweating ensuring the body doesn’t overheat

Performance

The release of biological analytes via the SNS and HPA axis work to prepare the athlete's body and mind, for performance in competition. Athletes can learn to harness stress and direct their focus on what is required to perform their best.

How we measure stress

Biological analytes

Biological analytes such as neurotransmitters, hormones, cytokines & catecholamines act as signal carriers and send messages to the body from the brain.

Hormones

Chemical messengers that travel in the blood stream and trigger a physiological response in cells with corresponding receptors.

Enzymes & Cytokines

Proteins that function as biological catalysts and enable biochemical reactions to occur more rapidly. Cytokines are small proteins that serve as a chemical communication network among immune cells.

Catecholamines

A type of hormone that also functions as a neurotransmitter. Released in response to emotional or physical stress and stimulate the central nervous system.

Neurotransmitters

Chemical messengers in the body that transmit signals from nerve cells to the target cells.

Cortisol

Cortisol is one of the most commonly measured biological analytes during a stress response.

Cortisol is released from the adrenal glands upon activation of the HPA axis, and is involved in multiple metabolic pathways, including regulation of blood glucose levels, our energy resource.

Cortisol Responses

Cortisol plays a large role in the stress response and associated physiological changes. Cortisol shuts down hunger and diverts blood and energy resources away from the digestive system. These physiological changes can feel like your mouth is going dry, feeling vomit-y or butterflies in your stomach.

The physiological responses induced by cortisol are designed to be adaptive and allow you to perform as required.

Measuring Cortisol​

When present, cortisol can be measured in the:

• blood
• saliva
• swear
• interstitial fluid
• tears
• urine
• hair

Some of these sample types can be quite invasive, may require a laboratory setting and large equipment for analysis which is not always practical, especially in sport.

Technology

New technology is emerging which is providing non-invasive ways to collect biological analyte samples. This includes such technology as wrist-wearable devices that analyses sweat, or a patch on the arm that can measure interstitial fluid through electrochemical signaling.

Validating this technology for use by athlete in training and competition is part of the research being undertaken by the Australian Institute of Sport (AIS).

Research team

The Australian Institute of Sport and the University of New England have partnered to provide the National High Performance Sports System with evidence-based information on stress and performance in competition.

Gemma Whelan

Postdoctoral Research Fellow, School of Science and Technology, University of New England

Gemma Whelan, MSc BSc, is a sport scientist and Postdoctoral Research Fellow with the School of Science and Technology at the University of New England. Gemma is tasked with exploring the validity of emerging biochemical sensors for the measurement of biological analytes, and their utility in sport to measure athlete stress in competition.

Gemma has previously worked within the Australian High Performance National Institute Network within the Performance Services team at the Australian Institute of Sport and at the Tasmanian Institute of Sport as a Sports Performance Officer.

Gemma completed her Masters of Sports Performance in the UK whilst coaching within the England Hockey Development Pathways.

Christian Cook

Professor in Biomedical Science, School of Science and Technology, University of New England

Professor Christian Cook, PhD, is a professor in biomedical science at the University of New England within the School of Science and Technology.

His expertise lies within the physiology and neurobiology of performance, stress​, neurobiology of learning, high performance science and technical knowledge acquisition and application under pressure in medicine. Christian also has a research background in biomedical technology design​, particularly in sensor design.

Christian has worked within high performance environments including several Americas Cup Yachting campaigns (2000, 2003, 2007), rugby world cups (2003, 2007, 2011, 2015) as well as preparations for both summer (2008, 2012, 2016, 2020) and winter Olympics (2006, 2010, 2014, 2018, 2022). Christian is a visiting professor at Imperial College London at Hamlyn Centre for Robotic Surgery, a centre that focuses on learning and technology in surgery and other fields of medicine, where he continues to undertake research.

Christian has over 200 publications and holds several patents and trademarks for his developments in technology.

Phillip Fourie

Associate Professor, School of Science and Technology, University of New England

Associate Professor Phillip Fourie, MBBS, is an Associate Professor and currently Deputy Head of School for the School of Science and Technology at the University of New England.

Phillip has a strong teaching background within the areas of clinical neuroscience, neuroanatomy, biochemistry and pathology within the medical program. Phillip’s primary research areas include anxiety, resilience and human performance, and Q Fever.  As a General Practitioner, he undertook several hospital placements in General Medicine, Accident and Emergency, Anaesthetics, Obstetrics and Gynaecology, Paediatrics and Oncology. Phillip completed a Post Graduate Diploma of Counselling in 2001 in line with his growing interest in applying a holistic approach to dealing with medical disease.

In 2013, Phillip completed a Doctorate of Counselling which focused on patient-centred assessment and treatment of anxiety disorder within the allied health context.