Is fatigue the brain's way of protecting the body?

University of Brighton researchers claim fatigue is the brain's way of saying "slow down"

Fatigue may be the brain's way of protecting the body, with exercise playing a key role in how people manage it, according to a new study.

Research from the University of Brighton suggests that about one in four 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, researchers said.

Dr Jeanne Dekerle, sports physiologist at Brighton's School of Education, Sport and Health Sciences, said: "Fatigue is the brain's way of saying, 'slow down' – not because you're weak, but because it's trying to keep you safe."

She added: "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."

'Regular physical activity'

This model of fatigue focuses on homeostasis – the body's ability to stay in balance, according to researchers.

"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," Dr Dekerle said.

"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 of "rebuilding trust" between the brain and body.

The next phase of the research is expected to explore how it works in real-world settings, including with athletes and patients with chronic illness.

The goal is to develop tailored exercise programmes to help manage fatigue more effectively.

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