A Randomized Crossover Trial on Acute Stress-Related Physiological Responses to Mountain Hiking.

Martin Niedermeier,Carina Grafetstätter,Arnulf Hartl,Martin Kopp

doi:10.3390/ijerph14080905

Abstract

Green exercise, defined as physical activity in natural environments, might have positive effects on stress-related physiological measures. Little is known about the acute effects of green exercise bouts lasting longer than 60 min. Therefore, the aim of the present study was to analyze the acute effects of a three-hour green exercise intervention (mountain hiking) on stress-related physiological responses. Using a randomized crossover design, 42 healthy participants were exposed to three different conditions in a field-based experiment: outdoor mountain hiking, indoor treadmill walking, and sedentary control condition (three hours each). At baseline and at follow-up (five minutes after the condition), stress-related physiological responses (salivary cortisol, blood pressure, and heart rate variability) were measured. Salivary cortisol decreased in all conditions, but showed a larger decrease after both mountain hiking and treadmill walking compared to the sedentary control situation (partial η2 = 0.10). No differences were found between mountain hiking and treadmill walking in salivary cortisol. In heart rate variability and blood pressure, changes from baseline to follow-up did not significantly differ between the three conditions. The results indicate that three hours of hiking indoors or outdoors elicits positive effects on salivary cortisol concentration. Environmental effects seem to play a minor role in salivary cortisol, blood pressure, and heart rate variability.

Highlights

Urbanization, considered as an increase in population in urban regions versus a decrease in population in rural areas, is an ongoing process worldwide
Stress and insufficient recovery from stress increase allostatic load, which is defined as the “wear and tear on the body and brain resulting from chronic overactivity or inactivity of physiological systems that are normally involved in adaptation” [6], has long-term effects on health and is considered as a risk factor for Western lifestyle diseases such as cardiovascular diseases, diabetes and mental disorders [7]
Both systolic and diastolic blood pressure (BP) were higher before outdoor mountain hiking compared to sedentary control condition and indoor treadmill walking

Summary

Introduction

Urbanization, considered as an increase in population in urban regions versus a decrease in population in rural areas, is an ongoing process worldwide. Urbanization is connected to physical, social, behavioral, and economic changes for the population, e.g., increased pollution, sedentary lifestyle, stress and stress-related diseases [2,3]. These changes represent a large challenge for the public health system, e.g., sedentary lifestyle is connected with increased mortality [4] and high economic costs [5]. Stress and insufficient recovery from stress increase allostatic load, which is defined as the “wear and tear on the body and brain resulting from chronic overactivity or inactivity of physiological systems that are normally involved in adaptation” [6], has long-term effects on health and is considered as a risk factor for Western lifestyle diseases such as cardiovascular diseases, diabetes and mental disorders [7]. Interventions to reduce stress and measures to support recovery from stress are highly needed

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