Harriet Martineau, the sociologist and social activist, would get up and go for a walk just as the sun rose each morning, she said, to prepare her brain for work. And science backs it up, because the best time to go for a walk is within the first hour after you wake up.
It turns out that light works as the main timekeeper for every cell in our bodies. And if we are exposed to this light within the first hour after waking up, each cell can set itself properly. We don’t need to expose ourselves to many hours of light, a walk of about 10 minutes and without sunglasses is enough. We don’t even need very bright light, because the light of a cloudy day is better than indoor light since it has many more lumens (the measure of light intensity).
Our sensitivity to light is lowest when we wake up, which is why the brain needs a burst of light to alert it and to adjust our circadian rhythms for the day. The morning light tells the neurons behind the eyes that it is time to get going so that the level of serotonin (the hormone that helps us sleep) is reduced. It also floods the body with cortisol, which wakes us up and stimulates us.
Morning light also causes the body to produce serotonin, which makes us feel good, regulates our sleep, and is later converted into melatonin to help us sleep.
Additionally, an early morning walk can protect our cardiovascular health by stimulating a gene that strengthens blood vessels and reduces the risk of a heart attack. For this reason, they occur more during winter. In one study, volunteers were exposed to 30 minutes of natural light between 8:30 a.m. and 9:00 a.m. each day for 5 days. At the end, they had elevated levels of the protein PER2, which adjusts the circadian rhythm, improves metabolism and strengthens blood vessels.
A study in 2012 showed that women who walked briskly for 45 minutes at 8:00 a.m. were more active during the rest of the day and were less hungry. It is believed that exercise raises our body temperature and as a result, hypothalamic neurons are activated, which help us regulate food intake. Another hypothesis is that it happens due to a hormone (GDF15), which also suppresses appetite when exercising.
There are more reasons to walk when you wake up, there is less pollution first thing in the morning, plants emit more negative ions between 9:00 and 10:00 (which lifts our mood), and we hear more birdsong (which is shown to cheer people up for up to 4 hours).
Let’s go out walking early!
Source: 52 ways to walk -Annabel Streets – Bloomsbury Publishing