Hormones and Physical Activity | Effects of Sport on Hormone Synthesis

Hormones and Physical Activity | Effects of Sport on Hormone Synthesis

By healthiergang writer Dr. Serena Garifo, Dietitian, Nutritionist,
Diet Coach and Fitness Expert (https://www.facebook.com/torinonutrizionista/)

Effects of Sport on Hormone Synthesis

Our endocrine system responds to motor activities of a certain entity trying to provide the best possible adaptation to changed physical conditions.

ACTH Ipofisario

One of the first interventions is consequent to the stress induced by training (and in general by prolonged physical work). This situation stimulates the release of catecholamines (adrenaline and noradrenaline) and, subsequently, of pituitary ACTH (adrenal-corticotropic hormone) which in turn stimulates the secretion of corticosteroids in the adrenal gland.

ACTH targets the cortical area of ​​the adrenal gland and stimulates the formation of glucocorticoids (the most important of which is cortisol) which influence the metabolism of sugars and the formation of androgens which have a muscle-enhancing function.


Cortisol, commonly called "stress hormone", is not produced constantly due to the discontinuity of ACTH secretion of the adenohypophysis: it is present in greater quantity in the morning (peak around 08:00) and in less quantity at evening.

The cortisol produced during physical exertion agonizes the activity of insulin, allowing to modulate the absorption of sugars by the cells and to favor a slow consumption in order to maintain glycemic levels as constant as possible and avoid energy drops. muscle fatigue and weakness.

When sports performance improves under the effect of training, the synthesis of cortisol gradually decreases as the body develops other abilities to adapt to muscular effort, such as the production of new mitochondria at the level of mycells, real fat-burning energy plants. .

This type of hormonal response, although common for each individual regardless of the subjective degree of training, is inevitably less marked for those individuals who habitually practice sports, and therefore suffer a lower degree of stress.

The interesting aspect is that a modest release of catecholamines is accompanied by a considerable energy consumption, since these neuromediators stimulate hepatic glycolysis (i.e. the use of hepatic glycogen) and lipolysis (i.e. the use of triglycerides of the adipose tissue ) to support the increase in heart rate and muscle work.

Under the effect of muscular effort, pituitary beta endorphins are also released with the role of modulating the adaptation and defense of the organism, counteracting muscle fatigue and stimulating the perception of a state of well-being.

GH: the Growth Hormone

Beta endorphins have a chemical peculiarity of the opioid type, their production following intense efforts tends to relieve painful states, and they also act indirectly on the release of GH.

Under the adaptive influence induced by training, the pituitary is stimulated to produce somatotropic hormone (better known as GH or growth hormone) and prolactin.

GH, an androgen hormone, has a general anabolic action on the body. Its release is proportional to the volume of the training and also to the size of the muscle masses used. Through its action the organism is pushed to use lipid reserves as energy substrates, safeguarding carbohydrates, increases the number of erythrocytes for stimulating the release of erythropoietin, stimulates the synthesis of new muscle mass (especially during the night in where there is the peak of this hormone, hence the importance of night rest for the synthesis of new muscle masses), increases aggression and grit.

Carbohydrate supplementation during sports, or the intake of carbohydrates, especially if with a high glycemic index, determines a marked inhibition in the release of GH. Furthermore, the triggered glycemic peak can cause a high insulin response, which determines the rapid uptake of circulating sugars, causing a feeling of exhaustion, which is not compatible with sports. The opposite situation, regarding the release of GH, occurs in the case of very low blood glucose levels.

The synthesis of GH after training starts about 10-20 minutes after the start of the activity, reaching its maximum peak after about 30-45 minutes from the start of the training. From these considerations it is clear that the maximum hormonal benefits can be obtained with short (no more than an hour) and naturally very intense workouts. Also because, the intensity of training determines the release of dopamine, noradrenaline, and serotonin with a stimulating effect on the release of GH.

Androgenic hormones

Sports activity can increase the normal production of androgens by a quarter, therefore of testosterone, but also of dihydrotestosterone (DHT) and delta-4-androstenedione. This increase is proportional to the increase in the maximum volume of usable oxygen, which in turn increases as a consequence of the hormonal stimulus.

In the female sex, follicular hormones (FSH and LH) can have negative effects on sports performance, in the same way, the practice of particularly intense sports, or a sudden increase in intensity, can cause the disappearance of the menstrual cycle or its irregularity. . This phenomenon would be attributed to the increased secretion of prolactin with inhibition of ovarian function and the appearance of an irregular cycle.

Sports practice can have consequences on the menarche, tending to postpone its appearance. These phenomena are attributable to the increase, in athletes, of the follicular period compared to the luteal phase, due to a decrease in the production of hypothalamic GnRH (precursor of gonadotropins).

Thyroid hormones

Finally, intense training sessions act on the blood level of the thyroid hormones T3 and T4 with a consequent increase in cellular metabolic levels and body metabolism, even in the resting phases. Milder jobs, on the other hand, would not induce significant changes.


The answers described above are only made for training sessions of a certain frequency and intensity.

To have an effect on the endocrine system it is essential to practice suitable physical activity at least 3 times / week with training sessions not under 40 minutes of activity.

Milder jobs, on the other hand, would not induce significant changes.

Furthermore, it must be borne in mind that these hormonal responses are influenced not only by the type of activity performed and the duration of the training session, but also and considerably by the caloric and nutrient composition of the diet.

Training in an ideal way without combining adequate nutrition means working at 50% of potential.

Always keep in mind that healthy eating, according to a personalized (and not standardized! Are we or are we not all different? Each with its physical potential and its metabolic machine that can be more or less performing) is a fundamental aspect for the achieving your training goals.

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