A landmark one-year clinical trial has proven that meeting the standard 150-minute weekly aerobic exercise goal causes a sustained reduction in long-term cortisol levels and slows the pace of brain aging.
The Research
In the first study of its kind, published online in the Journal of Sport and Health Science on March 17, 2026, researchers conducted a one-year randomized clinical trial to examine the long-term effects of aerobic exercise on stress biology. The study was led by Dr. Peter J. Gianaros of the University of Pittsburgh’s Center for Mind-Body Science and Health and Dr. Kirk I. Erickson of the AdventHealth Research Institute.
The trial included 130 adults aged 26 to 58. Participants were split into two groups: one group engaged in 150 minutes of moderate-to-vigorous aerobic activity every week for a year, while the other received general health information without changing their activity levels. Researchers monitored changes in cardiorespiratory fitness, cortisol, and other stress and emotion measures using brain imaging and advanced techniques.
Key findings include:
- Sustained cortisol reduction: Participants in the exercise group showed a significant drop in long-term cortisol levels, the body’s primary stress hormone.
- Slower brain aging: Prior data from the same trial revealed that exercise also slowed the pace of brain aging, suggesting physical activity protects both brain structure and chemistry.
- Mental resilience: The 150-minute weekly threshold appears to be a “sweet spot” for building biological resilience against conditions linked to high cortisol, such as depression, anxiety, and heart disease.
As Dr. Gianaros explained, “The effect of exercise on long-term cortisol levels could be one of the mechanisms or benefits of exercise that protect against several diseases and some mental health conditions.”
Why It Matters
This study provides robust, cause-and-effect evidence that regular aerobic exercise doesn’t just offer temporary stress relief—it rewires your body’s stress biology. By lowering baseline cortisol, exercise helps reduce the “background noise” of stress that can impair cognitive functions like memory, focus, and emotional regulation. High cortisol is linked to accelerated brain aging, so managing it through activity may help preserve cognitive health over time.
For anyone interested in brain performance, this research highlights exercise as a powerful, accessible tool to support mental resilience and long-term cognitive function.
What You Can Do
Aim for 150 minutes of moderate-to-vigorous aerobic exercise each week, such as brisk walking, running, cycling, or swimming. This aligns with standard health guidelines and, based on this trial, appears to be a key threshold for sustained stress reduction and brain health benefits. Start with manageable sessions and build consistency—your brain and body will thank you.
Source: Neuroscience News
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