A year-long study found that adults who exercised at least 150 minutes per week showed significantly lower long-term cortisol levels compared to a control group that received only general health advice.
The research, published in the Journal of Sport and Health Science, tracked 130 participants aged 26 to 58 over 12 months. One group engaged in moderate to high-intensity endurance activities such as brisk walking, cycling, or jogging. the other maintained their usual routines.
Cortisol, a hormone produced by the adrenal glands, plays a key role in the body’s stress response by increasing blood sugar, suppressing immune function temporarily, and heightening alertness. While essential for daily rhythms like sleep-wake cycles and metabolism, chronically elevated levels are linked to cardiovascular disease, metabolic disorders such as diabetes, and mental health conditions.
Participants in the exercise group demonstrated reduced cortisol concentrations by the study’s complete, with the effect persisting throughout the observation period. Researchers noted that sustained high cortisol is considered harmful, and regular physical activity may serve as a protective factor against stress-related illnesses.
Study lead Peter J. Gianaros stated that physical activity’s long-term impact on cortisol could be one mechanism through which exercise guards against various diseases and psychological strain. However, he emphasized that further investigation is needed to fully establish this protective effect.
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A parallel analysis of 81 adults confirmed similar findings, measuring cortisol via hair samples and assessing nervous system function through MRI scans. The exercise group again showed statistically significant reductions in cortisol compared to controls who received lifestyle information but did not change activity levels.
Both studies align on the threshold of 150 weekly minutes of endurance exercise as the point at which measurable long-term benefits to stress hormone regulation emerge. This amount aligns with World Health Organization recommendations for adult physical activity.
The findings suggest that consistent aerobic movement does more than improve fitness — it may recalibrate the body’s hormonal response to stress over time, offering a non-pharmacological avenue for disease prevention.
How much exercise is needed to lower cortisol long-term?
At least 150 minutes per week of moderate to high-intensity endurance activity, such as brisk walking, cycling, or jogging, was required to observe significant reductions in cortisol levels over a year.
Why is lowering cortisol important for health?
Chronically elevated cortisol is associated with increased risk of heart disease, metabolic disorders like diabetes, and mental health conditions; reducing it may help mitigate these risks.
