Cortisol: Misunderstood Magic

Cortisol is the hormone everyone loves to hate. Depending who you ask it’ll make you fat, bald and miserable. But it’s far more than a one-note boogeyman. 

It’s misunderstood as simply “stress hormone.” In reality, it’s a steroid hormone synthesised from cholesterol and is linked as much to circadian rhythms, metabolism and immunity as it is stress.

Put simply, cortisol is a means to release energy in the body and to direct it to particular tissue, especially the brain. We want high levels in the morning that slowly decline throughout the day, so we can sleep more easily in the evenings.

Recent years have seen wellness influencers use cortisol as a scapegoat for myriad health issues. It’s one of many big bad things you can avoid – “doctors hate you for this one simple trick!” – that change with the seasons. Fats in the 80s, carbs in the 90s… seed oils, you get the gist.

But, as with all these supposed villains, the truth is more nuanced and less marketable.

Second Out the Gate

Cortisol’s known by people outside of the performance crowd. Usually it follows some overused example of how our bodies react the same to being chased by a Jungle Book character as it does to an arsey email from the finance team – though the jury’s out on that one.

Yes, when we’re in danger we release cortisol. But not initially. The first port of call for the body is adrenaline and norepinephrine. These heighten your pulse rate, blood pressure, breathing, blood sugar and fat use. It opens the airways in your lungs for extra oxygen and pushes blood to your muscles. This whole process starts so quickly you don’t even have the chance to notice. It’s why, if you’re lucky, you can dodge a rogue car or a ball hurtling towards your bonce.

Adrenaline and norepinephrine give you either the fuel to leg it when Shere Khan’s after your thighs, or to fight him. But it only lasts up to an hour. Cortisol needs to be created and then released, so it’s not instantaneous – it peaks around 25 minutes after acute stress. It does this to keep you alert after a threat, maintaining blood sugar, shifting the way you metabolise nutrients and managing energy.

Morning Spark

You wouldn’t wake up if it wasn’t for cortisol. Known as the CAR (Cortisol Awakening Response), just before you wake up your body floods with cortisol. It drags glucose into your blood and flicks your brain back online after half a dozen hours of consolidating memories of workplace drama. Whenever you undersleep, or mess with your circadian rhythms by bingeing Love Is Blind, you alter the flow and wake up groggy. 

Source

Cortisol follows a rough 24-hour cycle of peaking just before you wake up and bottoming out sometime after midnight. The body stops creating cortisol when it thinks we have enough and creates more when it doesn’t.

There are all kinds of ways to tinker with cortisol, but the key takeaway should be to peak it early in the morning, which prompts a steadier decline throughout the day. This way you keep energy levels high when you need them, and your cortisol then lowers as melatonin raises in the evening, making for easier and deeper sleep. 

Nerd time, you have something called a suprachiasmatic nucleus pathway, which can be triggered through light stimulation.  Early in the morning, by looking in the direction of the sun, or into a SAD lamp, you can significantly increase your cortisol levels. Again, this isn’t a bad thing.

This is also the reasoning behind avoiding harsh artificial light in the evening, you don’t want to be artificially enhancing your cortisol when you’re soon to sleep.

Our body uses all kinds of cues to regulate its cortisol production. This is why you sometimes wake up before your alarm if you’ve got an early flight.

Crunches & Coffee 

The relationship between exercise and cortisol is effectively one of, ironically, training. Tough workouts will spike your cortisol as a means to transport energy, but the repeated process also enhances your body’s ability to spike and return to baseline.

When we habitualise the times we exercise, we turn it into an entrainment cue - cortisol rises in the hour or so before we start moving. The word from the wise seems to be that the earlier you can exercise, the better, if you’re trying to manage cortisol. This is because ideally we’ll have a gradual curve downwards of cortisol throughout the day. That said, if you can only train late at night, the benefits of exercise outweigh skipping sessions for the sake of cortisol alone.

Now Caffeine: if you don’t consume caffeine at all, introducing it into your diet will make a noticeable difference to your cortisol levels. If you’re used to it though and drink a regular number of cups/cans per day, your body adapts to the process. Instead, it smooths out the decline of cortisol reduction.

The Takeaways

The cycle of cortisol production is what you should be looking to optimise. 

Cortisol is far more than a stress hormone, it’s a way to tell our body that we need energy to move and think.

The sooner we can peak it, the better our performance throughout the day. Light is good in the morning and bad at night. 

The better we can shape our rhythms, respecting circadian rhythms, the better we’ll perform.