The everyday effects of sleep, exercise, heart rate, and mood—both good and bad—could linger in our brains for over two weeks, according to a pioneering study.

Finnish researchers tracked one person’s brain and behavioral activity for five months using brain scans and data from wearable devices and smartphones.

“We wanted to go beyond isolated events,” says research leader Ana Triana. “Our behavior and mental states are constantly shaped by our environment and experiences. Yet, we know little about the response of brain functional connectivity to environmental, physiological, and behavioral changes on different timescales, from days to months.”

The study found that our brains do not respond to daily life in immediate, isolated bursts. Instead, brain activity evolves in response to sleep patterns, physical activity, mood, and respiration rate over many days.

This suggests that a workout or a restless night even from last week could still affect your brain—and therefore your attention, cognition, and memory—well into next week.

Though the study wasn’t focused exclusively on physical activity, the results speak to what cardiovascular exercise guru Dr. Benjamin Levine recently said on a popular health and fitness podcast about how exercise should best be thought of as part of one’s “personal hygiene.”

Physical activity was also found in the Finnish experiment to positively influence the way brain regions interact, potentially impacting memory and cognitive flexibility. Even subtle shifts in mood and heart rate left lasting imprints for up to fifteen days.

The research is unusual, a release from Aalto University suggests, because few brain studies involve detailed monitoring over days and weeks.

“The use of wearable technology was crucial,” says Triana. “Brain scans are useful tools, but a snapshot of someone lying still for half an hour can only show so much. Our brains do not work in isolation.”

Triana was herself the subject of the research, monitored as she went about her daily life. Her unique role as both lead author and study participant added complexity, but also brought firsthand insights into how best to maintain research integrity over several months of personalized data collection.

“At the beginning, it was exciting and a bit stressful. Then, routine settles in and you forget,” says Triana. Data from the devices and twice-weekly brain scans were complemented by qualitative data from mood surveys.

The researchers identified two distinct response patterns: a short-term wave lasting under seven days and a long-term wave of up to fifteen days. The former reflects rapid adaptations, like how focus is impacted by poor sleep, but how it also recovers quickly. The long wave suggests more gradual, lasting effects, particularly in areas tied to attention and memory.

The study is also a proof-of-concept for patient research. Tracking brain changes in real-time could help detect neurological disorders early, especially mental health conditions where subtle signs might be missed.

“Linking brain activity with physiological and environmental data could revolutionize personalized healthcare, opening doors for earlier interventions and better outcomes,” says Triana in conclusion.