Circadian Rhythm: Respecting the Dark Side

Hi there, and a warm Spring welcome,

I’m sure you know already about the importance of getting outside in natural light. Luckily, because you’re a dog parent, that won’t be difficult! Your daily walk together benefits you in so many ways.

As you prepare for the walk, stroking your beloved pet and putting on their harness and lead will release oxytocin, the brain hormone that encourages us to feel safe and calm. Seeing your dog’s joyful anticipation release dopamine, the feel-good hormone that’s triggered when we know we’e brought joy to someone else.

As the walk begins, the exercise you take encourages the release of endorphins, which damps down any feeling of discomfort and confers a sense of wellbeing. And the light you can enjoy now that the days are longer will stimulate the production of serotonin, helping you to feel alert, focused and positively motivated.

As if that wasn’t enough, a daylight walk will also help regulate you circadian rhythm, or daily sleep/wake cycle. When you step outdoors, the natural light trails a direct pathway from your eyes to an area deep in your brain which is calle the Suprachiasmatic Nucleus, or SCN. This area, known as the ‘master clock’, can be thought of as your central control station. Tiny though it is, the SCN has powerful scope, controlling body temperature, appetite and emotional responses, and regulating our daily cycle of alertness.

OK, if an outdoor walk is all that’s needed to trigger and regulate our circadian rhythm each day, that’s all you need to do to feel alert and energetic early in the day and ready for sleep by late evening, right?

Not quite.

If in the evening, instead of observing the sunset and allowing only for lower, gentle lighting afterwards, you ramp up your indoor lighting and spend lots of time in front of screens, you won’t allow your brain to secrete melatonin. Those of you who’ve experienced jet lag after a long plane flight may have heard of melatonin, the brain hormone that encourages us to slow down, relax and prepare for sleep. If melatonin isn’t allowed to rise because the light around you is too bright, it will be hard to fall asleep.

In summary, then, you can see why that daily outdoor walk that you do for your dog is also for you, in so many beneficial ways. But please, don’t short-change those benefits by your behaviour in the evening!

To create—and maintain—a healthy sleep/wake cycle, start your day with a good dog walk. Then at the day’s end, don’t forget the importance of winding down slowly, respecting as much as possible the falling of each day’s gift of natural light.

Until next time, here’s to darkness as well as to daylight,

Best,

Linda