Sleep and Circadian Rhythms….our bodies natural cycles

*The above info graphic shows the natural rhythm our bodies are designed to go through during a typical 24hr period.

I worked earlies, lates and nights for six years and it has most certainly messed up my sleep patterns which I am slowly slowly clawing back to something resembling healthy!

At the time I never understood how important our natural sleep cycles and bodily rhythms are, or how they work. If I had more knowledge at the time I could definitely have done less ‘damage’ and got more out of training and probably been more effective at work.

Our bodies follow a rhythm and cycle that is as ancient as humans themselves, it runs in relation to a full revolution of earth, and therefore the rise and fall of the sun. Humans are designed to sleep or rest during hours of darkness and be awake during hours of light.

Poor sleep is a massive problem in todays society and improving sleep quality will have positive effects on body composition, performance, mood and health! It is my go to thing to change with clients and is one of the most important pieces of the health and fitness puzzle.

In the mornings, you wake up and your bodies will naturally have elevated levels of cortisol, a hormone with a number of functions, but which is mainly released at times of stress. This is normal, and a good thing, its an essential hormone for you to function as humans and it should be slightly elevated in the morning.

During the day, the cortisol levels should gradually decline and as you approach the evening, and sunset, the hormone melatonin is released. This hormone is responsible for the regulation of sleep, so it is important it is released in the evening before you try to sleep.

If you think about how we structure our lives, many of us have stressors in the evening, for instance training, watching television, working late, studying late etc.

This can raise cortisol levels just before bed and in relation to watching or using screens before bed it can inhibit the release of melatonin, as the light emitted from the screen signals to the brain that it is actually still daytime and that you do not want melatonin released yet.

So, many of our members train in the evening as it is the only time they can train. For those of you who train at this time, what can you do to help change this? Well, a stress response from training is good, you just need to get your body out of it as soon as possible after.

So try to implement these protocols to see if they help:

1- Spend 5-10 mins stretching and cooling down afterwards. Use this time to relax mentally and physically, step away from the buzz of training and bring yourself back to the real world. You can incorporate breathing drills into this as well.

2- When you get home, consume some carbohydrates with your post workout meal. This will help blunt the cortisol response and can help with the release for serotonin, a precursor to melatonin.

3- Dim lights and avoid screens upon getting home, start using this time to wind down and don’t ‘rush’ to bed. Take a bit of time to try and relax and digest your post workout meal properly.

Some other basic sleep protocols to implement include:

  • Sleeping in complete darkness, use blackout blinds to ensure there is no light source in your room
  • Avoid electrical devices 60-90 minutes before bed
  • Avoid alcohol before bed, this may feel like it knocks you out but the sleep quality under the influence of alcohol is MUCH reduced
  • Dim lights and keep them down until bedtime
  • Switch Off! Try and put a limit on working late or answering messages or calls late at night
  • Aim to be in bed by 2200hrs, between this time and 0200 is when most of our physical repair takes place. In my experience, 6-8 hrs of sleep is better from 2200hrs, than say 8-10hrs from midnight. The more in sync with our natural biological rhythms we can be the better!
  • If you can, incorporate 20-30 minute naps to top up your sleep. I personally struggle with this as I find it difficult to relax enough to sleep in the day, but if you can do it, it can help.



Lift Off CrossFit is based in Bishops Stortford, Herts. Our experienced team of coaches have made Lift Off the regions premier CrossFit box.

We welcome all levels of experience and pride ourselves on treating all members as equals.



If you are interested in coming down to meet us, please get in touch. We would love to hear from you!

 01279 755 333
 Unit 1, Twyford Business Centre
London Road, Bishops Stortford
CM23 3YT