The Physical Health Benefits of Green Exercise

Several studies have found green exercise to improve blood pressure, vitamin D levels, and heart rate variability beyond that of indoor physical activity. So today I’m diving into these findings, as I believe these endpoints are not only of interest to those that are ill but also healthy individuals.

Blood Pressure

With cardiovascular disease plaguing the globe, high blood pressure is a serious health concern as it is the most prominent risk factor for developing cardiovascular disease. To combat high blood pressure, doctors frequently recommend prescription drugs, with some recommending lifestyle changes such as reducing salt intake, increasing fruit consumption, and getting involved in regular exercise. But what about green exercise?

Researchers set out to determine whether green exercise lowered blood pressure to a greater extent than exercise alone. Following 20 minutes of light walking or jogging in a simulated green environment, adults demonstrated significant decreases in both systolic and diastolic blood pressures, compared to exercise alone. Similarly, the systolic blood pressure in children significantly decreased following 15 minutes of moderate cycling simulated green exercise, compared to the same exercise regime with no simulation.

So, if you or someone you know suffers from high blood pressure, adding green exercise into your weekly regime would be a favourable consideration.

People walking along a forested trail (Stock imagery)

Vitamin D Levels

With winter on the horizon, and with that less time in the sun, it’s time to start considering our vitamin D levels. Vitamin D deficiency can have serious implications on our physical health as it plays an important role in bone and muscle health. Additionally, inadequate vitamin D stores increase the prevalence of Seasonal Affective Disorder (SAD), which frequently occurs in the winter months when it’s darker for longer and we are outside less often. Luckily, your body has the ability to synthesize its own vitamin D when directly exposed to sunlight. So, compared to working out inside, being active outside leads to more sun exposure, thereby increasing our vitamin D levels.

Researchers noted the same thing when they compared a group of elderly individuals who partook in indoor hobbies (like going to the gym and dancing) to those who enjoyed outdoor hobbies (such as gardening, biking, and walking). What they found was an increase in circulating vitamin D in the blood of those in the outdoor group, compared to the indoor group.

So why not take advantage of these last few weeks of good weather and get outside as much as possible. Your body and mind will thank you!

A hedge growing in the shape of a heart (Stock imagery)

Heart Rate Variability

What is heart rate variability and why is it important? Heart rate variability is quite simply the variability in the time between heartbeats, and it plays a role in the regulation of our blood pressure, heart rate, breathing, and digestion. Typically, when our heart rate variability is low, we are in a “fight-or-flight” state, or in other words, we are stressed. Conversely, a high reading is reflective of a more relaxed state and is inversely related with cardiovascular disease risk. With this in mind, we should be aiming for a higher heart rate variability reading. So how can we increase our heart rate variability? Green exercise!

A couple of studies have seen an increase in heart rate variability after being outside in a forest environment, regardless of whether the individuals were walking, or just looking at it. Luckily for us Guelph residents, there are quite a few wooded trails in our city to take advantage of. Even Up and Running uses them during their sessions! Better yet, the leaves are beginning to change colour making those trails beautiful this time of year. So, I encourage you to get out there and enjoy!

In wrapping up this post, it’s important to mention that although favourable results were seen in the studies mentioned above, the idea of green exercise improving your physical health more than indoor exercise is still a major point of contention in the literature. While the research is much stronger for the mental health benefits, the physical health benefits appear to vary based on which study you look at. All of the studies I looked at saw improvements in physical health following green exercise, but the physical benefits did not always outweigh those seen following indoor exercise. But, an important takeaway is that you don’t need to spend money on costly gym memberships, instructor-led classes, or fancy equipment (unless, of course, you want to)! You can experience all the same physical health benefits by going for a free walk on a trail, or a bike ride with friends.

A similar concept was discussed in a book I’ve been reading called “How Not to Die” by Dr Michael Greger. In one chapter, Dr Greger lists the healthiest berries based on their antioxidant profiles. But he immediately follows it up by stating the healthiest berry for any given individual is the one they will enjoy and consume the most. The same idea applies here – if you’re more likely to work out at the gym on a regular basis because you prefer it to running outside, by all means, do that! On the flip side of the coin, if you prefer walking outdoors and can make a better habit of that than going to a fitness class, stick with your walks! If it gets you active more regularly, then that is what’s best for you!