The joys of having a newborn at home!  I have recently become the very proud dad of a healthy baby girl. This post is partly written with my own journey in mind - the last three months of constant sleep deprivation.

Let’s talk about sleep and body composition.  Sleep is a huge topic and when I have the time I plan to post about it in more detail but for now we’ll just run through some basics about what happens during sleep and why it’s relevant to your fitness goals as a personal trainer Sydney client.

The human body obviously requires a certain amount of sleep every day to function. The body has need for physical and psychological repair and to perform myriad other internal processes while the body is in a state of ‘complete’ rest.  As a society, sleep is something we undervalue and it’s importance is often overlooked when someone feels their performance is below par or they are having difficulties achieving their desired body composition.

Sleep is a natural process that occurs in line with nature’s light / dark cycles if we allow it to. Our hormonal rhythms are hard-wired to the rise and fall of the sun which triggers the release of a hormone called cortisol that enables us to wake, be active, and get things done. It is what is known as the ‘primary stress hormone.’ Ever been on a camping trip and noticed that you feel like going to sleep at 8pm instead of 11pm as you would in the city?  Yep? That’s the lack of artificial light allowing your body to begin its natural process of winding down and preparing for sleep.

Something I was unaware of until recently even though I have been a personal trainer Sydney for many years, is that babies are not hard-wired to these same light / dark cycles as the rest of us, they have not yet developed a mature ‘circadian rhythm‘ which is the regular 24 hour physiological cycle that we all follow as adults. This is why they think it’s perfectly fine to be wide awake at 2am and why it feels so painful for us.

A normal adult circadian rhythm, at a moderate latitude (i.e. not too close to the poles) and in summer, goes something like this:

6:00am - Cortisol is on its way to it’s peak, and we’re awake!
12:00pm - Cortisol is on its way back down as the day is already half over
6:00pm - Cortisol is on the down-low and melatonin has begun to rise
10:00pm - It’s dark outside now, cortisol is nice and low, melatonin is high and we are ready to crash for the night.

This rhythm doesn’t run a normal course for most of us in the modern world, we artificially extend our day by keeping the lights on late at night and many of us use computers or tablet devices until just before we hit the pillow. This keeps our cortisol levels artificially higher than nature intended and we end up with the below consequences according to the Mayo Clinic:

Cortisol, the primary stress hormone, increases sugars (glucose) in the bloodstream, enhances your brain's use of glucose and increases the availability of substances that repair tissues.

Cortisol also curbs functions that would be nonessential or detrimental in a fight-or-flight situation. It alters immune system responses and suppresses the digestive system, the reproductive system and growth processes. This complex natural alarm system also communicates with regions of your brain that control mood, motivation and fear.

In a nutshell, having more cortisol chronically in your bloodstream leads to more blood sugar and therefore higher levels of insulin, less muscle mass, less sex hormone production (lower libido), impaired digestion, lowered immune function, poor short term memory, mood swings and an appetite for simple carbohydrates. 

Sleep is kind of important. 

Make sure that your room is as pitch black as possible and you put on the mood lighting an hour or so before bed, pick up a book and put down the computer. Most clients feel a difference within three days.


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