In recent years, the intersection of environmental psychology and exercise physiology has garnered considerable attention, particularly on how natural environments influence human well-being. A groundbreaking study led by researchers from the University of Copenhagen and the University of Verona offers compelling evidence that exercising in green surroundings such as forests, beaches, and parks elevates mood, alleviates stress, and benefits cardiovascular function more significantly than equivalent exercise conducted indoors or in urban settings. This research not only enriches our understanding of the biopsychosocial benefits of nature exposure but also carries important implications for public health initiatives and urban planning.
The study recruited twenty-five young adult males to participate in a randomized crossover trial, designed to compare physiological and psychological responses to a one-hour brisk walk at a consistent pace of 6 kilometers per hour across three distinct environments: a natural green space (a forest park), an urban walking route, and an indoor laboratory setting equipped with a treadmill. By controlling for exercise intensity and duration, the researchers ensured that environmental variables would be the primary factors influencing measured outcomes. Subsequent to each exercise bout, comprehensive assessments were conducted, including hormonal analyses, heart rate monitoring, heart rate variability (HRV) measurements, and subjective self-reports of mood, stress, fatigue, and motivation.
A key finding emerged in the realm of stress physiology: salivary cortisol, a well-established biomarker of hypothalamic-pituitary-adrenal (HPA) axis activation, exhibited significantly greater reductions following exercise in the natural environment compared to urban and indoor settings. This points to an enhanced downregulation of stress responses when exposed to green surroundings, resonating with the biophilia hypothesis—that innate human affinity toward nature promotes physiological restoration. Moreover, heart rate data underscored the cardiovascular benefit of such surroundings, with participants demonstrating more rapid post-exercise heart rate recovery after walking in nature. This suggests enhanced autonomic regulation, corroborated by HRV analyses which revealed 20–30% higher vagal tone—indicative of robust parasympathetic nervous system activation and increased capacity for relaxation and recovery during green exercise.
Beyond physiological markers, psychological outcomes reinforced the superiority of natural environments for mental health. Participants consistently reported elevated levels of positive affective states—such as joy, satisfaction, and optimism—post-exercise in the forest park, alongside diminished negative emotions including anxiety, irritation, and boredom. The contrast was stark; boredom increased after indoor walking sessions, highlighting the potential monotony and disengagement associated with typical gym environments. These affective benefits were further reflected in participants’ expressed intention and motivation to repeat physical activity in green spaces, a key behavioral determinant vital for adherence to exercise regimens.
The integration of neuroendocrine and subjective measures in this research presents a more holistic understanding of how green exercise operates at the mind-body interface. The evolutionary perspective offers valuable explanatory power, positing that humans’ millennia-long adaptation to natural environments underpins intrinsic neural circuitry favoring such settings for psychological well-being. Associate Professor Stefano De Dominicis articulates this by emphasizing humans’ evolutionary roots in nature, fostering an innate “neurobiological affinity” that manifests in tangible mood enhancement and physiological relaxation during outdoor exercise.
Importantly, these findings challenge the prevailing exercise paradigm which often prioritizes indoor or urban spaces for physical activity, underlining the multidimensional benefits of nature that extend beyond physical exertion alone. While the social and practical advantages of indoor or team-based activities remain acknowledged—such as community engagement and sport-specific skills—the markedly superior mood regulation and cardiovascular recovery associated with green exercise makes a compelling case for integrating nature exposure into routine physical activity prescriptions.
The implications for public health and urban development are profound. Considering rising trends in sedentary lifestyles, stress-related disorders, and urbanization, promoting accessible green spaces could serve as a cost-effective, scalable intervention to improve population-level mental and cardiovascular health. The study’s authors advocate for municipal planners and health professionals to prioritize green infrastructure and develop exercise programs that facilitate regular interaction with natural environments, specifically targeting vulnerable populations such as individuals with obesity or mental health challenges.
Methodologically, the randomized crossover design strengthens the validity of the results by mitigating inter-individual variability and confounding factors. By having each participant serve as their own control across environments, the study achieves a high degree of internal consistency, enabling clearer attribution of observed differences to environmental context rather than physiological fitness or baseline psychological status.
Physiologically, the enhanced heart rate variability observed following natural environment exercise is indicative of improved cardiac autonomic balance, a critical factor linked to reduced risk for cardiovascular disease and better stress resilience. HRV is increasingly recognized as a non-invasive biomarker of autonomic nervous system flexibility, and its augmentation through green exercise highlights a tangible mechanistic pathway through which nature confers health benefits, reinforcing emerging models of environment-behavior-health interactions.
Furthermore, decreased cortisol levels following outdoor walking support evidence that green exercise attenuates HPA axis hyperactivity—a core component of chronic stress pathology implicated in disorders ranging from depression to metabolic syndrome. This endocrine modulation, combined with positive affective shifts, suggests that incorporating green exercise could contribute to holistic stress management strategies.
While the study focuses on young, healthy males, thus limiting generalizability across age, gender, and clinical populations, it sets an important foundation for further research. Subsequent investigations should examine diverse cohorts, longer-term interventions, and broader ecological contexts to refine guidelines for green exercise dose-response relationships. Additionally, exploration of neural correlates via neuroimaging could deepen mechanistic insights, elucidating how sensory inputs from natural environments modulate brain networks associated with emotion regulation and reward.
In summary, this research confirms that the environment in which exercise is performed significantly shapes both psychological well-being and physiological recovery. Green exercise not only enhances mood and mitigates stress more effectively than urban or indoor exercise but also improves cardiovascular autonomic parameters essential for health maintenance. These findings advocate for a paradigm shift in public health and urban design, integrating nature-based solutions as fundamental components of physical activity promotion and mental health enhancement in the modern world.
Subject of Research: The mental and physiological benefits of exercising in natural green environments compared to urban and indoor settings.
Article Title: Evaluating the benefits of green exercise: A randomized controlled trial in natural and built environments assessed for their restorative properties
News Publication Date: 1-Sep-2025
Web References:
http://dx.doi.org/10.1016/j.psychsport.2025.102883
Keywords: Human health, Physical exercise, Human biology, Public health, Behavioral psychology, Social psychology, Heart, Cardiac function, Brain evolution, Evolution, Human physiology, Physiology
