Walking is, inarguably, the most popular physical activity, and is suitable for all. For many, it is their primary form of exercise, and it helps to spice up the routine with its many variations – from brisk walking, done by increasing the pace of the walk, to interval walking, which is based on the same principle as an HIIT routine. It can be done indoors as well. On the other hand, treadmill walking is a popular warm-up or workout choice for many gym goers. Indoor walking provides the associated physical benefits, no doubt. However, doing it outdoors comes with the added benefits of sun exposure.
Walking in the sun
It is a common practice among people to use umbrellas while walking outdoors in the sun. All the more so at places where the sun is intense. However, experts recommend walking in the sun and sunlight exposure for a short period, as it can have many positive health implications.
“It helps build strong bones, prevent certain types of [skin] cancers, helps with systemic conditions, like rheumatoid arthritis, or inflammatory bowel diseases and boosts the immune system,” says Sidharth Unnithan, a sports medicine specialist from Kochi, Kerala.
Sun rays also stimulate many physiological functions in the body that enhance overall health.
Sunlight regulates the circadian rhythm
The circadian rhythm of the body, which is part of the biological clock, regulates several physiological processes, some of which are influenced by light.
“Walking in the morning increases the body temperature,” says Sneha Alexander, an exercise physiologist from Kannur, Kerala. “The sunlight exposure suppresses the production of melatonin [a hormone that is produced in the night time and helps with sleep], thereby regulating the sleep-wake cycle.”
Vitamin D synthesis
Walking in the sun maximizes the synthesis of Vitamin D in the body, which further improves bone health.
“On exposure to the UV B rays of the sun, the 7-dehydrocholesterol present in the skin forms pre-vitamin D, after which it gets converted to vitamin D, a very crucial vitamin for the body,” says Dr Unnithan.
Vitamin D promotes calcium absorption from food and is responsible for maintaining bone health and increasing immunity.
Sunlight’s impact on mental health
Sunlight can brighten your mood and enhance your mental health by stimulating the production of serotonin, a ‘feel good’ hormone.
“Having low serotonin levels can lead to anxiety and depression,” says Alexander. “The production of serotonin hormone, a kind of neurotransmitter, is enhanced by Vitamin D production, which happens due to exposure to sunlight. This hormone helps in regulating the mood and makes the person feel good and active.”
Best time to walk in the sun
Most people find it convenient to walk early in the morning or evening. Walking, in general, ensures good cardiovascular health along with other benefits such as weight loss, increased muscle and bone strength. So, the timing wouldn’t matter much, unless you are intending to stimulate vitamin D production.
“If your aim is to get sun exposure to trigger vitamin D production, then the best time to walk in the sun is a few hours after sunrise [after 9am],” suggests Alexander.
That is when the UV B radiation is high and can trigger Vitamin D production. The climate, the temperature, skin tone, and the duration of exposure are other factors that play a role.
Dos and don’ts of walking in the sun
Walking in the sun, especially if the heat is intense, can cause dehydration, heat strokes and heat headaches. Always carry rehydration drinks to avoid dehydration and replenish the lost water and electrolytes.
“Prolonged exposure to the sun can also cause skin damage, sun burns, damage to retina, and even certain types of cancers [skin cancers]. So, monitor how long you’re exposed to the sun and use sunglasses whenever needed,” says Dr Unnithan.
The vitamin D production can be impaired by body fat, melanin, sunscreen, and clothing. “So, try not to wear thick clothing or use sunscreen. Sunlight exposure time should be comparatively a little longer if you are dark skinned,” adds Dr Unnithan. This is because concentration of melanin in the skin influences the synthesis of vitamin D, as it can absorb and scatter the UV B radiations resulting in lesser synthesis when melanin content is high.
Takeaways
- Walking improves cardiovascular health along with other benefits such as weight loss and increased muscle and bone strength.
- Walking in the sun ensures exposure to sunlight, which in turn helps regulate the biological clock and enhances the production of vitamin D, crucial for maintaining bone health. It also increases the production of serotonin, which is a feel-good hormone.
- It is important to limit the duration of sun exposure. It can trigger heat headaches, heat strokes, and dehydration. Consume rehydrating drinks while out in the sun.
