Exercise has a huge impact on the functioning of the entire human body. In order to keep the body in relative homeostasis, cooperation between many body systems, including the endocrine system, is essential. The aftermath of physical activity includes an increase in body temperature, a rise in blood pressure or an increase in heart rate. Under normal circumstances, such symptoms would indicate a medical condition. Fortunately, our bodies adapt perfectly to current changes, and physical activity, despite its “negative symptoms”, has a beneficial effect on health.
Regular physical exercise of moderate intensity is recommended for everyone, regardless of latitude or living conditions. However, it is worth knowing moderation in training. Moderately intensive training, performed several times a week, improves our health, but working out until we are out of breath can put too much strain on the endocrine system. As long as we are not professional athletes, let’s rely on common sense – to make physical activity safe for us.
Physical exertion and... dehydration
Physical activity is closely linked to changes within the body’s water management. During exercise, body temperature rises, so we sweat more, and accelerated breathing increases the excretion of water vapour from the body. If it were not for the mechanisms developed by the endocrine system, our blood volume and blood pressure would drop dramatically during physical activity. Fortunately, the renin-angiotensin-aldosterone system is on guard — it is thanks to it that blood pressure rises, and the body retains sodium and water without leading to dehydration. Of course, this system is able to work, provided you are properly hydrated – which is why it is so important to consume fluids during training.
Post-workout anaemia
Thanks to the effects of aldosterone, even for two days after training, the blood remains in increased volume through reduced filtration in the kidneys. As a result, the blood is heavily diluted, resulting in lower erythrocyte or haemoglobin concentrations. If this is the case, the results of blood counts taken after training may erroneously indicate anaemia. Blood volume and concentration of its morphotic elements return to normal after some time. Those working out who suffer from anaemia should regularly monitor their blood results.
Physical exercise for insulin-resistant people
Physical exertion causes both temporary and long-term changes in the body, related to the regulation of water-electrolyte balance and nutrient metabolism. The body’s priority during sports activity is to increase the availability and metabolic rate of ingredients, needed by the muscles to work. Such a component is, among others, glucose, the concentration of which in the blood increases during exercise – under the influence of glucagon, epinephrine, norepinephrine and glucocorticosteroids. On the other hand, glucose uptake by working muscles is facilitated thanks to insulin (a hormone antagonistic to glucagon). It is through this mechanism that regular physical activity is recommended in order to regulate glucose-insulin metabolism in the body. Physical exercise reduces insulin resistance.
A workout for burning body fat
Adipose tissue is our own energy store in case of low availability of other, more easily metabolized energy sources (such as carbohydrates). When the body begins to run out of carbohydrates for current needs during exercise, it draws the missing energy precisely from body fat. Cortisol, the stress hormone, is involved in this process. Its concentration in the blood increases with the start of training, which triggers the processes of breaking down triglycerides into free fatty acids. Then, the processes of burning the free fatty acids are no longer handled only by cortisol, but also by catecholamines and somatotropin.
Physical activity and reduction of breast cancer risk
Physical activity reduces the concentration of sex hormones by increasing the level of sex hormone-binding globulin (SHBG) in the blood. This is especially important for breast cancer prevention. Oestrogens, produced in excess, can contribute to the proliferation of cancer cells in the breast glands. In the Alberta Physical Activity and Breast Cancer Prevention Trial, involving 320 menopausal women, regular physical activity was proven to have a beneficial effect on the hormonal profile of women in menopause, thereby reducing the risk of breast cancer.
Testosterone
Physical activity in men increases the concentration of testosterone in the blood. Studies show that the larger the muscle groups involved in exercise, the more testosterone appears in the bloodstream. The best results in this regard occur with strength training (compared to endurance training). The mechanism of post-workout testosterone levels in women is unclear. This can be especially important for women struggling with, for example, polycystic ovary syndrome (PCOS). On the one hand, physical activity in the form of strength training can contribute to increased testosterone levels in the blood, and on the other hand, it is an excellent element of treatment of obesity and insulin resistance, which very often co-occurs with PCOS. Certainly, regular physical activity in women with endocrine disorders has more benefits than negative effects.
Sources:
Kinga K. Borowicz, Aspekty biochemiczne i patofizjologiczne aktywności fizycznej (“Biochemical and Pathophysiological Aspects of Physical Activity”), 2013.
Maria Litwiniuk, MD, PhD, Izabela Kara, MD, PhD, Aktywność fizyczna a nowotwory (“Physical Activity and Cancer”), 2012.
Marta Anna Stachowicz, Anna Lebiedzińska, Dieta a testosteron w organizmie sportowca (“Diet and Testosterone in the Body of an Athlete”), 2015.