The Link Between Sunlight and Better Sleep

Sunlight and time outdoors can powerfully impact your overall well-being. Light’s range of health benefits includes positive effects on mood, alertness, and sleep quality. That’s what makes outdoor activities the perfect start to one’s morning. They get your blood pumping, oxygen flowing, and energy going early in the day.

With the benefits of sunshine in mind, hiking, biking, bird watching, and other outdoor activities are optimal for mental and physical health.

At no surprise, studies show that there are far more advantages to healthy sunlight exposure than disadvantages of people spending too much time outside. This has a lot to do with sunlight’s influence on our circadian rhythms.

What are circadian rhythms and how do they benefit human health?

Circadian rhythms are a natural pattern of mental, physical, and behavioral changes that the body undergoes in 24-hour intervals. In essence, it’s your body’s internal clock that dictates your daily sleep-wake periods.

The sun’s light/dark cycle has been proven to have favorable effects on the circadian clock, attentiveness, and sleep (according to the CDC).

Our circadian clock’s natural response to light is staying awake, and its response to darkness is going to sleep. The CDC recommends maximizing light exposure in the daytime to increase your alertness. To sleep better at night, you should shut off all sources of light, including cell phones, TVs, tablets, and digital clock radios in your bedroom or place of rest.

[Related: Get the Blue Zones Bedroom Checklist]

The great outdoors and how it contributes to lowered stress levels

Outdoor exercise and recreation have other benefits as well. One study, published by ScienceDirect from the Journal of Affective Disorders, associates greater time outdoors with lowered chances of lifetime major depressive disorder.

The 400,000+ participants of this study revealed that they spent a median of 2.5 daylight hours outdoors. Each additional hour spent outside was linked to reduced antidepressant usage, greater happiness, and less tiredness.

The initial year of the pandemic also brought a lot more people outside, as many had extra downtime due to lockdowns and job losses. This caused an uptick in green space usage during that time, which reportedly fosters greater health.

According to another study published by The University of Colorado Boulder, and published in the journal PLOS One, outdoor exposure at COVID-19’s peak boosted mental health in the wake of pandemic-related stressors.

Those facilitating the study gathered 1,200 people for a survey between November 2019 to January 2021. The survey’s aim was to compare participants’ opinions on green spaces near their residences. Many study participants reported that they went outside to relieve stress, which helped them reduce cases of anxiety and depression.

The study backs a theory called ‘biophilia hypothesis’, which suggests that humans crave connections with the outdoors. The supposed reasoning for this is that the environment positively influences stress hormones and promotes healing from disease. Conclusive research from the study alludes to the importance of people having greater accessibility to green spaces, especially during times of crisis.

How well can daytime sunlight improve a baby’s sleep cycle?

A 2014 study on this confirms the relationship between natural light exposure and an infant’s quality of evening sleep. The clinical trial led by the Journal of Sleep Research concluded that babies who ended the study well-rested were more exposed to light during early afternoons. Specifically speaking, sunlight had a positive influence on the 24-hour circadian systems of 6-12-week-old infants.

FYI: Sunlight does more good than harm

A common assumption about sun exposure is that the sun’s damaging rays can mitigate the benefits of time outdoors. However, this isn’t entirely true. It’s only hazardous when you overdo it. Too much time outside, especially during the day, can have damaging effects on skin health.

Excessive UVA radiation can indirectly cause skin cancer when it penetrates the skin. This is caused by the DNA-damaging molecules–such as oxygen or hydroxyl radicals–that are generated as a result. One thing to keep in mind is that exposure to UVR only accounts for 0.1% of the world’s disease burden in disability-adjusted life years (DALYs). The World Health Organization revealed this in their 2006 report, The Global Disease Burden Due to Ultraviolet Radiation.

Robyn Lucas, a coauthor of the report and epidemiologist, noted that most diseases caused by overexposure to UVR are proportionately benign (excluding malignant melanoma). Such diseases may have high prevalence and require action in the form of preventative measures–especially for older age groups. In spite of this observation, however, most UVR-linked diseases maintain a low disease burden.

If anything, healthy exposure to sunlight has a plethora of great health benefits. Your body gets sufficient boosts of vitamin D and you experience positive changes to your mood while you’re soaking in all that great sunshine.

Get outside more: It’s the Blue Zones way!

In the blue zones, time outside is a daily practice. Centenarians would undoubtedly say that it’s one of their secrets to longevity. Partaking in outdoor activities can have you sleeping more, feeling better, and paying more attention to your surroundings as a result of its positive effects on your circadian clock.

It doesn’t take much to enjoy moments in the great outdoors. From stepping out in the mornings to enjoy cups of coffee in nature, to taking afternoon strolls during break times, you can maximize your time outside with little effort.