1. Overview
In a world dominated by indoor activities and sedentary lifestyles, the chance to step outside and embrace nature often feels like a precious rarity. From the moment we wake up, we seamlessly transition from one enclosed space to another—home, school, work, gym, maybe a brief stop at a bar or restaurant. However, breaking away from this routine and venturing outdoors for exercise can offer a revitalizing change that not only benefits your body but also rejuvenates your mind and spirit.
Whether it's a leisurely stroll through a park or an invigorating trail run in the mountains, outdoor exposure has emerged as a potent antidote to the stresses of modern life, offering a plethora of mental health benefits. In this post, we will explore the extensive benefits of outdoor activity.
2. Vitamin D Boost
One of the key benefits of outdoor exercise is the opportunity to replenish your body's vitamin D levels. Vitamin D, often referred to as the "sunshine vitamin," is crucial for bone development and health, as well as supporting immune function, the nervous system, and musculoskeletal system. Unlike other vitamins that are more prevalent in food, vitamin D is not naturally found in many foods. Vitamin D is mainly synthesized in the skin through direct sunlight exposure. When UVB rays from the sun penetrate the skin, they trigger a chemical reaction that converts a precursor molecule in the skin into an active form of vitamin D, known as calciferol. Yet, due to modern lifestyles characterized by limited sun exposure and increased time spent indoors, approximately 35% of adults in the US face a vitamin D deficiency. [1] ,[2]
The consequences of vitamin D deficiency can be far-reaching and detrimental to your health. Chronic deficiency has been linked to an increased risk of various health problems, including weakened immune function, bone disorders such as osteoporosis and rickets, cardiovascular diseases, depression, and even certain types of cancer, mainly colorectal and bladder. Moreover, individuals with vitamin D deficiency may experience symptoms such as fatigue, muscle weakness, bone pain, and a compromised mood. This deficiency is particularly prevalent among individuals living in urban areas or those with demanding work schedules that keep them indoors for extended periods. [3], [4], [5], [6], [7]
As a result, engaging in outdoor exercise becomes not only a means of physical activity but also a vital strategy for addressing vitamin D deficiency. Even a brief stroll under the sun can significantly boost your vitamin D levels. According to experts at Harvard Medical, just 10 to 15 minutes of sun exposure on your arms and legs a few times a week can fulfill most of your vitamin D needs. However, achieving these "right circumstances" can be a little tricky, as factors like season, time of day, location, cloud cover, and pollution levels all influence the amount of UVB radiation your skin receives. Nevertheless, by prioritizing outdoor activities, you can proactively improve your overall well-being, tackle the widespread vitamin D deficiency prevalent in today's society, and reduce the risk of associated health issues. [8]
3. Cognitive Benefits
Engaging in outdoor activities transcends mere physical exercise; it serves as a potent catalyst for elevating mood and cognitive function. Whether meandering through a serene park or conquering rugged trails amidst nature's embrace, the transformative impact of such experiences on your emotional equilibrium cannot be overstated. This profound connection between nature and your psychological state is substantiated by a wealth of empirical research, which illuminates the numerous ways in which natural environments positively influence your mental health and cognitive functions.
Stress & Anxiety Benefits
- A key study in 2015 looked at the impact of a 90-minute nature walk on rumination, a pattern of repetitive negative thinking linked to depression. It also examined neural activity in a region associated with rumination. Results showed that after the nature walk, participants reported less rumination and had reduced brain activity in this region, suggesting nature's potential to improve mental health. In contrast, these effects weren't seen after an urban walk, highlighting the specific benefits of nature on well-being. [9]
- In a 2016 study in Brisbane, Australia, researchers analyzed data from 1538 residents to understand the link between nature experiences and health outcomes. They found that spending at least 30 minutes in green spaces weekly was linked to a potential reduction of up to 7% in depression cases and 9% in high blood pressure cases in the population. Longer and more frequent visits to green spaces were associated with lower rates of depression and high blood pressure, as well as increased social cohesion and physical activity. Even after adjusting for factors like age, gender, income, and education, these associations remained significant. [10]
- A 2019 study with 36 urban participants showed that spending time in nature at least three times a week for 10 minutes or more reduced participant’s stress levels. Nature exposure, particularly sessions lasting 20-30 minutes, significantly decreased stress. Biomarker analysis revealed a remarkable 21.3% decrease per hour in salivary cortisol levels, surpassing the natural decline rate of 11.7%. Alpha-amylase, another stress marker, decreased by 28.1% per hour, even after accounting for its natural rise of 3.5% per hour. Interestingly, the specific activity during the nature experience did not significantly affect cortisol response. [11]
Enhanced Cognitive Functions
- In a 2008 University of Michigan study led by Berman, Jonides, and Kaplan, it was discovered that a 50-minute nature walk can enhance working memory by up to 20%. Participants experienced memory improvement solely after walking in natural environments, rather than urban settings. Interestingly, even during Michigan's winter, participants derived benefits, although they tended to favor nature walks in warmer seasons. [12]
- A 2012 study done by psychologists from the University of Utah and the University of Kansas found that spending time outside improved people’s score on the Remote Associations Test which measures creative potential using word associations. Participants who took the test after a four-day hiking trip scored an average of 50 percent higher than those who took the test before the hiking trip. [13]
- In 2015 University of Melbourne researchers tested 150 subjects with a task involving specific keystrokes upon seeing certain numbers on a computer screen. After a five-minute task session, subjects were given a 40-second break, during which half viewed an image of a plain concrete rooftop and the other half viewed a green, flowering meadow on a rooftop. Upon resuming the task, concentration levels dropped by 8% for those who saw the concrete roof, while increasing 6% for those who saw the green roof. [14]
4. Immune System Benefits
Breathing in the fresh, clean air of the outdoors, we absorb phytoncides—airborne compounds emitted by plants as a defense mechanism against insects. These phytoncides boast antibacterial and antifungal properties, serving as a frontline defense for plants against diseases. Remarkably, when humans inhale these natural chemicals, your body reacts by bolstering the population and vigor of a specific type of white blood cell known as natural killer cells (NK). These vigilant cells specialize in targeting and eliminating tumor- and virus-infected cells within your body, fortifying your immune system's response to potential threats.
The two studies offer compelling evidence regarding the beneficial effects of forest bathing, the practice of immersing oneself in a natural forest environment, on human immune function, particularly in enhancing natural killer (NK) cell activity.
- In a 2007 study, twelve healthy male subjects embarked on a three-day forest bathing trip. Post-trip analysis revealed a significant increase in NK cell activity, along with notable rises in the percentage and total number of NK cells. Additionally, levels of granulysin, perforin, and granzymes, vital components of NK cells, were found to be elevated following the excursion. [15]
- A subsequent study in 2008 compared the impact of forest bathing with that of a city tourist visit on NK cell activity and numbers. Results confirmed that forest bathing led to a significant enhancement in both NK cell activity and numbers, contrasting sharply with the negligible effects observed during the city tour. Furthermore, the study unveiled that the heightened NK cell activity and numbers induced by forest bathing endured for more than 7 days, and in some cases, up to 30 days after the excursion. [16]
5. Increased Caloric Burn
Engaging in exercise on uneven trails offers a unique and challenging terrain that can lead to increased calorie burn compared to exercising on flat surfaces. The irregular surfaces of uneven trails require the body to constantly adapt and stabilize, engaging more muscles and intensifying the workout. With each step, the body navigates inclines, declines, rocks, roots, and varying terrain, which not only activates major muscle groups but also recruits smaller stabilizing muscles for balance and coordination. This dynamic movement pattern demands greater energy expenditure, resulting in a higher calorie burn compared to exercising on flat ground. Additionally, the uneven terrain often necessitates a slower pace, prolonging the duration of the workout and further contributing to calorie expenditure.
- A 2013 study examined the physical changes of walking on uneven terrain compared with smooth surfaces in 11 healthy men and women in their 20s, using a special treadmill that mimicked moving over trails, grass, and uneven pavement, thereby requiring relatively minor adaptations in walking technique. The researchers, from the University of Michigan, noted that walking on a surface that varied by only 2.5 cm (1 inch) from a flat smooth one resulted in an extra 28% increase in calorie-burning than normal. [17]
6. Takeaways
The benefits of exercising outdoors—from enhancing physical fitness to reducing stress, improving cognitive function, and bolstering immunity—are undeniable. So why not step outside, breathe in the fresh air, and embark on a journey to a healthier, happier you? Trade the treadmill for a trail, swap gym walls for a park, and exchange screen time for sunshine. As little as 10-15 minutes a day can begin to provide benefits. The great outdoors awaits, ready to rejuvenate your body and mind.
