What’s the relationship between hormones and exercise?

When we talk about sport and exercise, it’s easy to forget about the vital role our hormones – the body’s plucky little chemical messenger signals – play.  

Yet hormones have been shown again and again to influence our physical performance.

So, it’s time we talked about the relationship between hormones and exercise.

Associate Professor Severine Lamon from Deakin University’s Faculty of Health agrees. When we talk about hormones and exercise, she says, it’s vital we distinguish between circulating hormones in general, like endorphins, and sex hormones like estrogen and progesterone, which regulate menstrual cycles.  

‘Many hormones play a role in growth, development, maintenance of our muscles and bones, and adaptation to various physiological stressors, including exercise or disease,’ she says.   

How exercise affects your hormonal system

So, how do your hormones change when you exercise? Do they always respond in the same way, or do they differ from person to person?   

Exercise is a major body stressor. The “stress” due to exercise triggers positive adaptations for the body (via the release of cortisol). This is called physiological stress – in this case it is positive. It basically prepares the body to better respond to the next bout of exercise (the training effect).

Assoc. Prof. Lamon says that cortisol – the body’s ‘stress’ hormone, vital in fighting inflammation, maintaining liver function and regulating the body’s sleep schedule (in theory, anyway)– acutely responds to just 10-15 minutes of moderate to high intensity exercise, like treadmill sprints or jump roping.  If our hormones aren’t at the right levels during these exercises we may not perform at an optimal level. 

Cortisol is created by the adrenal glands, which hang casually just above the kidneys. The pituitary gland – that pea-sized bump in the brain that bossily directs every other gland – regulates cortisol production. This intricate dance is essential for our health to maintain an adequate balance of cortisol.   

Does exercise affect the male hormone system differently?   

Most studies conducted in males indicate that resistance exercise and training increases testosterone concentrations, but some have found no, or very small effects. This response can be affected by the muscle group involved (i.e. exercise selection), exercise intensity and volume, nutritional intake, training experience and many other factors.. However, Assoc. Prof. Lamon notes this research is inconclusive.   

‘There have been several studies on how sex hormones respond to exercise over the past 20 years, and they do not all agree with each other. One of the biggest issues in exercise physiology studies is that they usually make conclusions from limited sample sizes, leading to conflicting results across the literature,’ she explains.   

A third hormone released during exercise is somatotropin, commonly called growth hormone (or GH for short). We do see a significant increase in GH secretion through aerobic and resistance exercise, though the amount of GH released differs by gender and the age of the individual.   

The good hormones exercise releases (spoiler: it’s for your bones!)  

Since exercise releases hormones that generally have a positive effect. What are the good hormones exercise releases?

Feel-good hormones like endorphins are typically the main ones we associate with exercise, but the benefit that might not have seen coming is improved bone health. Forget your nightly glass of milk – these hormones are the real deal.  

So which hormones are released during exercise?

When it comes to the business of good bones, there are nine key hormones that significantly impact our bone health and Assoc. Prof. Lamon says the roles of our endocrine hormones– jet-setting chemicals that travel through the bloodstream before acting on faraway cells – are critical.   

‘Endocrine hormones are involved in the delicate balance between bone formation and bone resorption and alteration in sex hormones with ageing. For instance, a reduction in estrogen in women and testosterone in men, shift the balance towards bone resorption which increases the risk of osteoporosis.’  

What does this mean for athletes?  

As well as performance when we exercise our hormones are also responsible for reducing our risk of non-contact injuries.

In recent years, we have seen several serious knee injuries in the AFLW, and debate rages on about whether this is linked to hormonal imbalance or not. It’s a similar question to whether testosterone is the key to women’s athletic performance.  

‘There has been an increase in research around sex hormones and injury risk. Female sport is important to bridge the gap in our understanding of how female athletes might perform or obtain injuries differently to male athletes,’ says Assoc. Prof. Lamon.  

‘It is essential research continues as it remains critical for us to better understand injury mechanisms and assist practitioners to implement best practice methods towards reducing injury risk in female athletes,’ she continues.   

Remember, if you’ve felt a little off lately, there’s no harm in making an appointment to see a physio.  

Our hormones must be well balanced when we exercise to perform at the best possible level, regardless of what form of physical activity we are participating in.