Cardiorespiratory Fitness May Lower Depression Risk by 36%, Study Finds

Can fitness protect your mind? A major study finds higher cardiorespiratory fitness significantly lowers the risk of depression and dementia. Discover how even small improvements can safeguard your mental health.

Maintaining good levels of cardiorespiratory fitness may significantly contribute to preserving mental health, as highlighted by a major scientific review. Cardiorespiratory fitness involves how effectively the heart and lungs work together to deliver oxygen during continuous physical activity. While researchers have long noted relationships between physical health and mental wellbeing, this study focuses specifically on how fitness itself might affect the risk of developing serious mental and brain-related conditions.

Study Review

The research was conducted by an international group of scientists from the University of Castilla-La Mancha, in collaboration with experts at the Karolinska Institutet. Their findings were published in the journal Nature Mental Health.

Dr Bruno Bizzozero Peroni, a post-doctoral researcher at Karolinska Institutet and the study’s senior author, explained that the goal was to better understand mental health from a preventive perspective, looking beyond just physical activity to a more accurate measure of fitness.

The research team performed a systematic review and meta-analysis of 27 long-term studies, involving more than four million participants of various ages. These studies tracked individuals who were initially free from mental or neurocognitive disorders and monitored their health over time.

Fitness was assessed using exercise tests or estimates of oxygen consumption, and researchers then compared how different levels of fitness related to the development of various conditions.

Key Findings

The results revealed a consistent pattern: higher cardiorespiratory fitness was associated with a reduced risk of several mental health and brain-related disorders.

Individuals with better fitness had a 36% lower risk of depression, a 39% lower risk of dementia, and a 29% lower risk of psychotic disorders. There was also a 10% lower risk of anxiety, although this finding was not statistically significant enough to confirm it definitively.

The researchers used a method called the hazard ratio to assess risk over time. This allowed them to compare the likelihood of developing conditions based on participants’ fitness levels.

The analysis also included various disorders, such as schizophrenia, bipolar disorder, ADHD, obsessive-compulsive disorder, somatic symptom disorders, and sleep-related conditions. However, not all of these disorders had sufficient data to allow combined analysis.

Health Impact

A key discovery was that even modest improvements in fitness had notable benefits. A slight increase of just one MET (a measure that reflects a small increase in physical exertion, like moving from rest to light walking) was linked to about a 5% lower risk of depression and a 19% lower risk of dementia.

This suggests that the benefits of fitness are not exclusive to highly active individuals and can be achieved through minor lifestyle changes.

The researchers believe these findings could shape future public health approaches. The researchers stated that fitness is a measurable and modifiable factor, making it a valuable component of prevention programmes.

The study also highlights the need for more research involving children, young people, older adults, and populations in regions outside Europe and North America. Future studies will also investigate potential biological mechanisms, such as brain plasticity, inflammation, and stress responses.