Feeling wiped out? Brighton researchers say fatigue may be more about your brain than your body

Around 1 in 4 people experience general fatigue at some point in their lives, especially when dealing with long-term health conditions or serious illness. Unlike pain, which can often be quickly treated with medication, fatigue is harder to pin down and has no single remedy.

Now, researchers at the University of Brighton have uncovered new insights into why we feel fatigued – and how we might manage it better.

Led by Dr Jeanne Dekerle, a sports physiologist at Brighton’s School of Education, Sport and Health Sciences, the study suggests that fatigue isn’t just about being physically tired. Instead, it’s the brain’s way of protecting the body from doing too much.

“Your brain is constantly checking whether your body can keep going without getting into trouble,” explains Dr Dekerle. “Fatigue is its way of saying ‘slow down’ – not because you’re weak, but because it’s trying to keep you safe.”

Dr Jeanne Dekerle

This new model of fatigue focuses on homeostasis – the body’s ability to stay in balance. When the brain predicts that continuing activity might push the body out of balance, it sends out fatigue signals to encourage you to stop or rest.

The study, published in the journal Sports Medicine, also found that regular, gentle physical activity can help the brain adjust its predictions. Over time, this can reduce feelings of fatigue.

Rather than pushing through exhaustion or doing intense workouts, the research encourages measured, consistent activity – like walking, stretching, or light cycling – as a way to rebuild trust between the brain and body.

“Even small amounts of movement can make a difference,” says Dr Dekerle, who is also a researcher at the University of Brighton’s Centre for Lifelong Health. “By being active, even at low levels, you retrain your brain to trust that your body can cope. This can help everyone from elite athletes to people living with conditions like cancer and multiple sclerosis, where fatigue is often a major challenge.”

For too long, fatigue has been seen as a personal failing. This research offers a new perspective: fatigue is a protective signal, not a weakness. Understanding this could help people manage their energy better and improve their quality of life.

The next phase of the research will explore how this model works in real-world settings, including with athletes and patients with chronic illness. The goal is to develop tailored exercise programmes that help people manage fatigue more effectively.

Staff related to this story

Dr Jeanne Dekerle

Reader – School of Education, Sport and Health

Public Health and Health Conditions Research Excellence Group, Centre for Lifelong Health