How To Optimize Your Day With Neuroscience: Morning Walks

My current routine is up at 5:00 AM, an hour of work, and then out the door for a 30-ish minute walk around beautiful downtown Austin TX. Writing this down, I realize half of you still have a disgusted look plastered all over your face at the thought of getting up at 5:00 AM. I’m here to tell you the secret to getting up earlier and capitalizing on your day is getting your butt out the door first thing.

I have always been an early riser, but even so, I used to spend the early hours of my day mainlining caffeine while trying to pry my eyes open. This stopped almost immediately after I added morning walks into my routine. Originally my plan was to use these walks to burn off a little extra fat. I quickly realized they were also improving my energy, cognition, sleep, and reducing my anxiety. Being a scientist at heart, I dove into the literature. Turns out I had accidentally stumbled upon one of the most underrated bio-hacks out there, and these added benefits had to do with my circadian rhythm.

Your circadian rhythm is controlled by a small clump of neurons within your brain called the Suprachiasmatic Nucleus (SCN). This system essentially works as a 24-hour clock that regulates your rhythmic bodily functions. Things like body temperature fluctuations, sleep and wake times, and specific hormone releases are all under control by this system (1). By getting outside first thing, you get increased levels of natural sunlight in your eyes. This stimulates a group of photoreceptors called retinal ganglion cells (2). These directly connect to the SCN and strengthen your awareness that it is daytime.

Exposure to this natural light strengthens your body’s awareness of where it is within the 24-hour (ish) cycle (3). This sunlight stimulates your SCN which initiates the release of a potent hormone. Cortisol, commonly known as the “stress hormone” naturally spikes first thing in the morning (4). This morning spike in Cortisol helps you achieve full alertness, fire up your motor system, and generally helps kick your body into gear for the day (4). Following this short spike, levels should decrease throughout the day. Combined with this short burst of Cortisol, natural light directly stimulates arousal (non-sexual) areas within your brain to further increase your wakefulness.

If these immediate effects are not enough to convince you, the benefits continue right up until you go to bed. If you follow a somewhat predictable schedule for waking up and going to bed, this increased awareness of where you are in time better prepares you for sleep. Think of this like walking to the bathroom in complete darkness. You have a general idea of where you are, but stick your hands out looking for specific landmarks. Once your hand finds that couch or wall, you receive an immediate update to where you are in space. With this updated position, you can more efficiently navigate to the bathroom. Your circadian rhythm works similarly. Morning light serves as that “landmark” and updates your SCN to where you are in time. These landmarks help your circadian rhythm optimize your body temperature, hormone levels, and dozens of other physiologic systems so that they are in the sweet spot when you decide to go to bed. This has been clinically shown to, (A) advance the timing of sleep to earlier hours, (B) affect the duration of sleep, and (C) improve sleep quality (3).

To be perfectly honest, everything up until this point can be accomplished from your porch with a cup of coffee and a donut in hand. Here is where the walking bit becomes important. The act of forward ambulation, a.k.a. propelling yourself forward, allows objects to flow by your periphery. Meaning as you begin to walk, things on either side of you flow in and out of your vision. This visual flow has been shown to quite the activity in an area of the brain called the Amygdala (5). This is commonly referred to as the “fear center” of your brain. What few people know is that the Amygdala is also in charge of regulating anxiety. This means the simple practice of walking in the morning can attenuate those anxious feelings you may have about the test or presentation you have later that day. Data shows that as little as 2 minutes can be sufficient to start seeing some of these effects, but upwards of 30 minutes is where you will begin maximizing these benefits.

By adding this simple and quite pleasant ritual to my daily routine, I have seen immense benefits. My caffeine intake has been cut in half, and I feel less groggy. Coupled with increased sleep efficiency, I often wake up at 5 AM without an alarm. These are no doubt connected to my productivity going absolutely ballistic during the day. It's because of these reasons that

I highly recommend you integrate this zero-cost and massively beneficial routine into your mornings.

For more info on how you can optimize your circadian rhythm, check out @Grimmel_Biometrics on Instagram.

References:

1. Welsh DK, Takahashi JS, Kay SA. Suprachiasmatic nucleus: cell autonomy and network properties. Annu Rev Physiol. 2010;72:551-77. doi: 10.1146/annurev-physiol-021909-135919. PMID: 20148688; PMCID: PMC3758475.

2. Chiara La Morgia,Valerio Carelli,Michele Carbonelli. Melanopsin Retinal Ganglion Cells and Pupil: Clinical Implications for Neuro-Ophthalmology. Front. Neurol., 07 December 2018 | https://doi.org/10.3389/fneur.2018.01047

3. Christine Blume,Corrado Garbazza,Manuel Spitschan. Effects of light on human circadian rhythms, sleep and mood.Somnologie (Berl). 2019; 23(3): 147–156. doi: 10.1007/s11818-019-00215-x

4. Eva Fries, Lucia Dettenborn, Clemens Kirschbaum. The cortisol awakening response (CAR): Facts and future directions. International Journal of Psychophysiology 72 (2009) 67–73.

5. de Voogd LD, Kanen JW, Neville DA, Roelofs K, Fernández G, Hermans EJ. Eye-Movement Intervention Enhances Extinction via Amygdala Deactivation. J Neurosci. 2018 Oct 3;38(40):8694-8706. doi: 10.1523/JNEUROSCI.0703-18.2018. Epub 2018 Sep 4. PMID: 30181134; PMCID: PMC6596227.