The Effect of Outdoors Activity on Sedentary Behaviors

Background: The integration of physical activity into everyday contexts, including cultural and natural environments, represents a promising strategy to counteract sedentary behavior and promote cardiovascular and metabolic health. Walking is a highly accessible form of physical activity that can be performed in both structured indoor settings and ecologically valid outdoor contexts, such as culturally relevant walking routes. The aim of this doctoral work was to investigate the physiological and perceptual responses to walking exercise performed in indoor and outdoor environments, and to provide a methodological framework for the classification of walking intensity and walkability based on objective and subjective measures. The project was structured into four main phases: (1) development of a standardized protocol for psychophysiological data collection during outdoor walking; (2) evaluation of walking-related metabolic and cardiovascular responses across different environments; (3) comparison of acute hemodynamic adaptations, including post-exercise hypotension, following indoor and outdoor walking sessions; and exploratory assessment of the feasibility and physiological impact of a multidimensional physical activity intervention in a clinical case of Type 1 Diabetes. Across the experimental studies, participants completed walking sessions while physiological variables such as heart rate, blood pressure, oxygen consumption, and energy expenditure were continuously monitored using portable and laboratory-based devices. Exercise intensity was expressed both in absolute terms and relative to individual maximum heart rate, and perceptual responses were assessed using validated scales of perceived exertion and enjoyment. Acute cardiovascular responses were evaluated before and after exercise to assess post-exercise hypotension in indoor and outdoor conditions. Overall, the findings indicate that outdoor walking performed under naturalistic conditions elicits cardiovascular and metabolic responses comparable to those observed during structured indoor walking, supporting its effectiveness as a health-enhancing physical activity. The exploratory clinical case further suggests that multidimensional physical activity interventions may be feasible and well tolerated in individuals with Type 1 Diabetes, although generalization is limited. This work provides methodological and applied insights into the use of walking as a sustainable and inclusive physical activity, highlighting its potential role in health promotion when embedded within natural and cultural environments. Methods: This doctoral work integrates three complementary studies involving a total of 38 participants (37 healthy recreationally active adults and 1 individual with Type 1 Diabetes) to investigate cardiovascular, metabolic, and perceptual responses to indoor and outdoor walking. The first study presents a standardized protocol for the psychophysiological characterization of hiking, combining laboratory-based treadmill testing and field-based hiking sessions. Measures included heart rate (HR), heart rate variability, blood pressure, oxygen consumption, energy expenditure, rating of perceived exertion, and physical activity enjoyment, collected using portable and laboratory-based instrumentation. The second study experimentally compared acute hemodynamic responses following an outdoor hiking session (~3800 m) and an indoor maximal walking test of comparable duration (~40 min) in 37 young adults. Systolic and diastolic blood pressure, HR, and rate pressure product were assessed at rest, immediately post-exercise, and up to 30 minutes post-exercise. The third study explored the effects of a multidimensional indoor and outdoor exercise intervention in one individual with Type 1 Diabetes, integrating continuous glucose monitoring, insulin intake, dietary assessment, and perceptual measures. Results: The first article describes the development of a standardized protocol aimed at the psychophysiological characterization of walking and hiking. The protocol integrates laboratory-based treadmill testing and field-based outdoor sessions and is designed to be applied to participants stratified by sex, age, and physical activity level. Across sessions, physiological and perceptual variables, including heart rate, heart rate variability, blood pressure, oxygen consumption, energy expenditure, rating of perceived exertion, and physical activity enjoyment, are assessed using portable and laboratory-based devices. This methodological framework provides a harmonized approach for evaluating the cardiovascular and metabolic demands of outdoor walking under ecologically valid conditions. The second article experimentally investigated acute cardiovascular responses to indoor and outdoor walking in 37 healthy young adults (18 females, 19 males). Participants completed an outdoor hiking session (~3800 m) and an indoor maximal walking test of comparable duration (~40 min). Systolic and diastolic blood pressure, heart rate, and rate pressure product were measured before exercise and up to 30 minutes post-exercise. Both walking conditions elicited significant post-exercise hypotension, with systolic blood pressure reductions of 10.4 ± 2.1 mmHg following outdoor walking and 12.3 ± 2.3 mmHg following indoor walking. No significant differences in post-exercise hypotension were observed between environments (p > 0.05), despite higher relative exercise intensity during indoor walking. The third article presents an exploratory case study conducted in one individual with Type 1 Diabetes, evaluating the effects of a differentiated indoor and outdoor walking intervention. Continuous monitoring of blood glucose, insulin intake, dietary habits, sleep quality, chronotype, and physical activity levels was performed. Across the intervention, time spent in hyperglycemia (>250 mg/dL) decreased from 56.5% to 0%, while time within the target glycemic range (70–180 mg/dL) increased to 63.9%. A reduction of approximately 47% in daily insulin requirements was also observed. Outdoor walking sessions were perceived as more enjoyable than indoor sessions. Across all three articles, involving a total of 38 participants, walking performed in both indoor and outdoor environments induced meaningful cardiovascular and metabolic responses. Outdoor walking elicited physiological adaptations comparable to structured indoor exercise, including significant reductions in blood pressure and favorable metabolic responses, while offering higher perceived enjoyment. Conclusions: The integrated findings of this doctoral work demonstrate that outdoor walking performed under naturalistic conditions is a feasible and effective form of physical activity capable of eliciting cardiovascular benefits comparable to indoor exercise. The proposed standardized protocol provides a robust framework for the assessment of walking-related fitness, while the exploratory clinical evidence suggests potential applicability in specific health contexts. Together, these results support the inclusion of outdoor walking within health promotion strategies and environmentally meaningful physical activity interventions, while highlighting the need for further research in larger and more diverse populations.