Nature walks linked to lower nighttime heart rate in women

Spending time in nature during the day may be associated with better recovery already the following night – at least for women. This is shown in a new study from the University of Gävle, where researchers for the first time combined GPS data and heart rate measurements to examine how resting heart rate and signs of stress are affected by everyday exposure to natural environments.

A total of 45 participants in Gävle took part in the study. Their movement patterns were tracked for up to ten months using GPS, while their heart rate was measured at night with wearable devices.

– The unique aspect of this study is that we followed people in their everyday lives, out in real-world settings rather than in an experimental environment. We see that on days when people spend more time moving in nature, for example by walking or cycling, this is followed by a night with signs of better recovery, says Karl Samuelsson, researcher in environmental science at the University of Gävle.

Two measures of recovery

The researchers focused on resting heart rate and heart rate variability (HRV), two established measures of how the autonomic nervous system functions.

– A low resting heart rate and high HRV are linked to better health and lower stress levels, says David Hallman, professor of occupational health science.

The results show that more active movement in natural environments is associated with lower resting heart rate and higher HRV at night, clear signs of improved recovery. The associations are statistically significant but relatively small, which is expected since the measurements reflect individual days in people’s everyday lives.

– Previous experimental studies have shown similar effects, but in controlled settings. Here we see that it also applies in real life, which strengthens the evidence, says Karl Samuelsson.

“A robust study”

The study also reveals differences between women and men. The associations were clear among women but not statistically significant among men. One possible explanation is the smaller number of men in the study, although the findings are in line with previous research suggesting that the stress-reducing effects of nature may be stronger in women.

– This is an unusually robust study with credible scientific results on the health benefits of planning green corridors where people commonly walk and cycle. It also lays the foundation for new research: the health benefits of nature exposure were only observed among women, which raises important questions in the research community, says Stephan Barthel, professor of environmental science.

Although the daily effects are small, the findings suggest that regular exposure to nature may have long-term health benefits. The study was conducted in Gävle, a city with good access to green spaces, highlighting an important issue for future urban planning.

– Our results support the importance of having nature close to people in everyday life and easily accessible, for example within walking or cycling distance, says Karl Samuelsson.

The researchers emphasize the need for further studies to examine long-term health effects, whether the positive impacts become stronger over time, and how they may differ between genders.