Strength training increases testosterone by 40%

Strength training is really a kind of hormone therapy, write researchers at the Spanish University of Extramadura in the European Journal of Applied Physiology. According to the researchers, regular weight training raises testosterone levels by forty percent.

The Spanish researchers did an experiment with twenty male students who had never done serious training before. First the researchers measured the concentration of hormones like testosterone and cortisol in the students’ urine. That was measurement A. Then the researchers got the students to do a training session. The students had to do seven exercises, designed to exercise the biggest muscle groups. Afterwards the researchers measured the hormone concentrations again. That was measurement B.

The table below shows the concentration of the androgenic hormones in the test subjects.


The testosterone concentration decreased. That’s logical: through power training muscle cells absorb more androgens from the blood, and as a result the testosterone level goes down.

The power training increased the concentration of cortisol, see below.


After that the researchers got the test subjects to train regularly for another four weeks. Each week the students had to go to the gym three times and complete their programme. During that period the students became more muscled and stronger of course. After the four weeks, the researchers measured the hormone concentrations in the students’ urine again: once when they were at rest, just before doing a training session – measurement C – and once immediately after a training session – measurement D.


The production of testosterone – the table shows it clearly – is almost forty percent higher when the body is resting. After training the testosterone level is lower, but it doesn’t take a genius to guess that the level recovers quickly. The students’ estradiol levels were somewhat higher [we haven’t included a graph here] but the increase was not significant.

The level of the stress hormone cortisol on the other hand was lower, both at rest and after the training session.


If you do weight training over an extended period, your body starts to make more anabolic hormones and less catabolic stress hormones. Maybe that’s why people who start to train for the first time in their lives don’t notice any progress in muscle mass or strength immediately, but only after a couple of weeks. Their bodies have to adjust to the change.

Variations in urine excretion of steroid hormones after an acute session and after a 4-week programme of strength training


Performing strength exercise, whether acutely or in a training programme, leads to alterations at the hypothalamic-pituitary-testicular and hypothalamic-pituitary-adrenal axes. One way to evaluate these changes is by analysis of the excretion of steroid hormones in the urine. The present study determined the variations in the urine profile of glucuroconjugated steroids after a single session of strength exercise and after a 4-week programme of strength training. The subjects were a group (n = 20) of non-sportsman male university students who worked out 3 days a week [Monday (M), Wednesday (W) and Friday (F)], performing the exercises at 70–75% of one repetition maximum strength (1-RM). Four urine samples were collected per subject: (A) before and (B) after a standard session prior to initiating the training programme, and (C) before and (D) after the same standard session at the end of the study, and they were assayed by gas chromatography coupled to mass spectrometry. The concentrations of the different hormones were determined relatively to the urine creatinine level (ng steroid/mg creatinine) to correct for diuresis. After the exercise sessions, both before and after the training programme, there was a fall in the urine excretion of androgens and estrogens, but no statistically significant changes in the excretion of tetrahydrocortisol (THF) and tetrahydrocortisone (THE). The anabolic/catabolic hormones ratio also decreased after the acute session, although only androstenodione + dehydroepiandrosterone (DHEA)/THE + THF ratio had a significant decrease (P < 0.05). After the training programme, there was a significant (P < 0.01) improvement in the strength of the muscle groups studied, and an increased urinary excretion of all the androgens with respect to the initial state of repose, with the difference being significant in the case of epitestosterone (Epit) (P < 0.05). The androsterone (A) + etiocholanolone (E)/THE + THF ratio increased significantly (P < 0.05) concerning the initial state. We therefore conclude that subjects suffer variations of the urine profile with regard to the steroid hormones before and after the acute strength sessions and after the training period. The alteration after the training programme seems to be due to the subjects’ hypothalamic-hypophysis-testicular and hypothalamic-pituitary-adrenal axes adaptations, which enable them to increase physical strength. Source: