All about hormones: part 1 cortisol

Part 1: Cortisol

Ahh my most treasured hormone this one. Cortisol- the stress hormone. The one that makes you fat, old and want to eat carbs. Yes that one, the bad one. Let’s talk about it.

The Pituitary Gland

This gland sits at the base of the brain, just behind and between the eyes. Otherwise known as the master gland, it secretes a whole host of hormones as well as talking to the other glands, telling them when they need to secrete hormones too.

The main hormones produced by the pituitary are:

  • Adrenocorticotrophic hormone (ACTH) – this stimulates the production of cortisol, responsible in maintaining blood pressure and blood sugar levels.
  • Follicle-stimulating hormone (FSH) – promotes sperm production and ovaries to produce oestrogen.
  • Luteinizing hormone (LH) – stimulates ovulation in women and testosterone in men.
  • Growth hormone (GH) – Helps to maintain healthy muscles, bones and fat disruption.
  • Prolactin (PRL) – Responsible for breastmilk after birth. Also controls the ovaries and testes which can affect menstrual cycle, sexual function and fertility.
  • Thyroid Stimulating Hormone (TSH) – Stimulates the thyroid gland which regulates metabolism, energy and nervous system.
  • Anti-diuretic hormone (ADH) – Regulates water balance and sodium levels.
  • Oxytocin – Helps to labour and helps it to progress, breast milk to flow and breastfeeding, behaviour, social interaction and mother and child bonding at birth.

As you can see the pituitary gland has quite the job of keeping us working properly!

Introducing Cortisol

In this post we will be focusing on the hormone cortisol. You will generally see this hormone mentioned in relation to stress, usually in that it will make you store excess belly fat. And this is true – to some degree. When you are stressed, your brain sends a signal to your body to tell it to hang on to the excess energy from food. In essence it thinks you are going to be dealing with either a big stand off with the worlds biggest hungriest tiger. Or about to sprint a marathon away from said tiger.

Your heart rate and blood pressure will increase, your muscles start to tense as you gear up for the event. And in either of those cases, this wouldn’t actually be a bad thing. The problem arises from long term exposure to stress. Even though as humans we have adapted to our current lives, and running away or fighting tigers is no longer an issue, our brains don’t know this. Your brain has no way of knowing the difference from a physical stress to one caused by everyday life.

It is true that we now live in a world where we are exposed to low level stress all the time. This is a bad thing. Constant stress is where the problem lies. When we release sudden bursts of stress, our bodies are quite good at dealing with the situation. We are designed to fight or run from our situation; something physical. Once the deed is done, our brains will send signals to the rest of the body that today all is well and we can take 5. No damage done. But with today’s world there is rarely that take 5, which means constant stress.

We worry about getting to work/school on time, rushing out the door, we worry about the clothes we have on, our size and shape. Work or study deadlines, money, our family and friends. The list of worrisome things is never ending.

Chronic Stress

Over time this is where the problem can arise and when cortisol becomes a problem. We aren’t dealing with it and so it can leave our brains in a constant, let’s get ready to… state. We store fat ready for energy, whilst muscle mass starts to decline, blood pressure will rise, our sleep can get affected, either too little or too much. For women, menstrual cycles can be disrupted and men could be facing impotency. Mental health can take a bit of hit too.

In extreme cases – and this is where pituitary diseases comes into play – stretch marks can appear, fatty buffalo humps, osteoporosis, depression, excess facial hair in women, hair loss on the head, reduced sex drive, a large amount of excess fat around the middle and face, red, flushed looking face, brittle nails, thin, easily damaged skin, poor healing of soft tissues, muscle weakness and loss. The list will go on. The good news is that you are very unlikely to experience these symptoms. These are caused by a huge excess of cortisol, normal due to a small benign tumour on the pituitary gland. Say hello to Cushing’s disease, That’s my little friend that I have had the pleasure of being friends with twice. Chances of having this is about 1 in million, so don’t panic!

But it’s not all bad. Without cortisol, our bodies wouldn’t be able to function. Your blood pressure and heart rate would drop. You would feel dizzy, extremely weak and any stress could send you into shock, known as an adrenal crisis.

This would carry a high risk of a coma or death. So you kind of need it. Without it you are looking at Addison’s disease, in my case I have secondary Addison’s as a result of my last tumour removal. To live and function I have to take replacement cortisol every day. Probably for the rest of my life.

Exercise and Cortisol

Most of the research suggests that our stress response changes with different forms of exercise. For many years Yoga has often been recommended for stress due to its focus on breathing and calming nature, basically it doesn’t raise your heart rate very much. The same can be true for other types of exercise such as walking, gentle swimming, Pilates and tai chi.

The reverse can be true for more ‘stressful’ types of exercise such as HIIT training, heavy weight lifting and intensive exercise where the heart rate climbs. However, the effects of cortisol rising is short lived. It will rise and then a few hours later should fall to a normal level.

The same will be true of the least intensive exercises – the effects are short lived. They will help to lower stress, but if you are then exposed to that stress, the hormones will rise again,

The Take Home

As you can see, cortisol is a vital hormone, and one that gets a bad rep, but only when it is chronic. In terms of exercise, gentle low impact maybe beneficial if you are feeling overwhelmed and will help to lower your stress. Better for later in the day, it may well help you have a better sleep. Higher intensity exercise however, can be useful if you have feelings of unrest and frustration. That pent-up energy can be released through exercise. This is where a boxing session might just be worth booking!

Overall, to avoid the symptoms of chronic stress, managing them on a day to day basis is important. Learn to say no, read, listen to music, practice mindfulness or learn a craft. Along with exercise this will help to keep your stress hormones in check.






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