By: Marleen van Balkom On: June 10, 2016 In: Fitness, Health, Metabolite of the month, Nutrition Comments: 0

Testosterone is one of the most important hormones in our bodies – for both men and women! Let’s take a closer look at how testosterone affects us and what to do to boost its level:

During a man’s life, testosterone serves many key functions. The development of the testes and maturation of sperm cells depends on testosterone as well as the maintenance of muscle mass.

Interestingly, love and partnership show a strong link to testosterone. New couples that are still in their “honeymoon” phase, which lasts for 1-3 years, often experience a striking reaction on a hormonal basis: While the man’s testosterone levels decrease upon falling in love, the woman’s concentration is thought to rise. After a few years, however, the levels go back to their usual concentration. Additionally, the baseline testosterone levels of a heterosexual man contributes to whether or not he is in a relationship: Men with a partner commonly have lower baseline concentrations than singles.

In addition, the libido of both women and men depends to some extent on their testosterone levels. Thus, treatment of women who experience a decline in their interest in sex can be achieved with low doses of androgens, to which testosterone belongs. On the other hand, sex is thought to elevate testosterone levels and that of other hormones like endorphins.

It is not surprising that fatherhood also influences testosterone levels in men: Both testosterone and cortisol, the stress hormone, were found to decline upon birth of a child, while at the same time estradiol levels rise. Taken together, these changes imply a behavioural change towards more empathy and promote paternal care.

Just like the hormones that are important for female sexual reproduction, a man’s testosterone level varies with age: During early childhood, testosterone levels are low in both sexes, but in boys they begin to rise at the age of 6. In men, the highest levels of bioavailable testosterone are reached from 18-39 years. After that, most men experience a decline in testosterone levels. A woman’s level is generally much lower than that of men.

Age-related decline in testosterone levels in men and women (Source:

Unfortunately testosterone reduction is often associated with different health issues and even some serious conditions. Low testosterone levels can result in erectile dysfunction and a low sex drive and scientific studies of recent years have shown that this age-related decline is also linked to obesity and heart conditions, including a correlation with sudden cardiac arrest. Testosterone is also associated with many age-related diseases including a likely effect on attention and memory with some studies even suggesting that low testosterone levels may be a risk factor for cognitive decline and Alzheimer’s disease.

There are several supplementation treatments available to increase testosterone, ranging from patches applied to the skin to muscular injections.

Remarkably, researchers observed an interesting side-effect of testosterone supplementation: Men who were given injections of testosterone regularly for a few years unexpectedly lost weight. On average, the participants lost 14 kg and 11 cm in waist circumference.

While the underlying molecular basis has not been identified so far, two theories might explain this phenomenon: Higher testosterone levels influenced the behaviour and might have made the participants of the study more active, leading to a higher interest in sports, which in turn might have led to weight loss.

On the other hand, obesity and testosterone levels are known to be tightly linked: Fat tissues produce an enzyme called aromatase, which is responsible for the breakdown of testosterone into estrogen, its female counterpart. The result could be a vicious cycle: Weight gain could diminish testosterone levels, leading to decreased activity, which in turn results in more fat tissue, further reducing testosterone.

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Testosterone levels are dependent on body fat – and the other way around! Body fat lowers testosterone levels, but higher testosterone levels lead to increased activity, resulting in decreased body fat. (Source:

In addition, testosterone is known to act on dopamine release in the brain. Dopamine is an important neurotransmitter associated with mood, memory, pleasurable reward, sleep, movement and other body functions. Both dopamine and testosterone are positively correlated with each other, and high levels of one increase the levels of the other.

If you have participated in our development phase of Kenkodo, take a look at your testosterone levels at!

Where do you stand in comparison to the other Kenkodo users? Can you see an impact of increased training or did your diet have an influence?

Now that we know a lot more about testosterone and how it affects us, how can we boost it when the level is at risk?








Here are a few tips to increase your testosterone naturally: Vitamin D and zinc, two important substances that are necessary for our overall health, are also known to play a role in rising testosterone levels. Healthy fats as those found in avocados, olive oil and seafood are also necessary for testosterone production.

Something that is often forgotten when it comes to optimising your health, is sleep – and a good night’s sleep is crucial for a high testosterone level!

Most importantly, the best way to elevate your testosterone levels is exercise. As you have read earlier, testosterone levels are decreased by fat tissue, so losing weight is essential if you want to increase your testosterone. But exercise is much more than that! Especially high intensity weight training using sets with low numbers of repetitions but high weights is known to positively influence testosterone levels. So get moving 😉

Thus, there are a lot of reasons why it’s so important to keep an eye on your testosterone levels and this is why we have included this sex hormone in our Wellbeing panel.



Testosterone therapy for reduced libido in women

Rosemary Basson


Relationship status and testosterone in North American heterosexual and non-heterosexual men and women: Cross-sectional and longitudinal data

Sari M. van Anders & Neil V. Watson


Changes in Testosterone, Cortisol, and Estradiol Levels in Men Becoming Fathers

Sandra J. Berg & Katherine E. Wynne-Edwards


Mayo Clinic on Testosterone Levels


Effect of testosterone on metabolic rate and body composition in normal men and men with muscular dystrophy

S Welle, R Jozefowicz, G Forbes & R C Griggs


Testosterone Has Benefits for Metabolism, Weight Loss


Androgens, aging, and Alzheimer’s disease (2006)

Christian J. Pike, Emily R. Rosario, Thuy-Vi V. Nguyen


Association of Testosterone Therapy With Mortality, Myocardial Infarction, and Stroke in Men With Low Testosterone Levels (2013)

Vigen et al.


7 Smart Ways to Boost Your Testosterone


How Body Fat is Correlated with Testosterone Levels


Testosterone Levels in Men and Women with Age


Testosterone and Dopamine