person using free weights to train for fitness and health

Scientists Discover How Exercising Muscles Communicate With the Brain to Fight Depression

June 15, 2026 | Source: PsyPost | by Eric W. Dolan

Physical exercise helps relieve symptoms of depression, and new evidence points to a specific protein released by muscles as a primary reason why. A recent study published in Molecular Psychiatry suggests that a protein called apelin travels from exercising muscles to the brain to enhance neuron growth and improve mood. This discovery offers a better understanding of how the body and mind interact during physical activity.

Major depressive disorder is a severe mental health condition characterized by persistent low mood and a loss of interest in rewarding activities. Medical professionals often recommend physical exercise as a natural way to alleviate these symptoms. Exercise tends to improve mental health by promoting changes in the hippocampus, a brain region involved in mood regulation and memory.

Older adults experiencing age-related muscle loss, a condition known as sarcopenia, often have an increased risk of mental health conditions. “Sarcopenia is significantly linked to depression and cognitive decline in older adults, prompting interest in muscle-secreted factors that influence hippocampal function,” said Sonata Suk-yu Yau, an associate professor in the Department of Rehabilitation Sciences at the Hong Kong Polytechnic University.

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