Written by Ben Bunting: BA(Hons), PGCert. Sport & Exercise Nutrition. L2 Strength & Conditioning Coach.
Many sports or even professions (military personnel, first responders) require a level of endurance to succeed.
This article we look at how testosterone affects endurance capabilities, we cover the following areas:
- Testosterone’s effect on endurance
- How can you increase testosterone?
What is Testosterone?
Testosterone is the male sex hormone secreted almost entirely by the testes in response to a signal from the pituitary gland.
In females, it is secreted by the adrenal cortex and ovaries at a substantially lower amount than in males. In male adults there is around a 18x greater plasma concentration compared to female adults.
Testosterone is responsible for the maturation of puberty and the maintenance of physical appearances throughout adulthood which result sin the typical male characteristics.
These typical male anatomical characteristics are determined by two different sets of chromosomes.
The first set, X and Y, determines the sex of the individual. The second set, called autosomes, determines physical characteristics other than gender.
The genes on the autosomes are not related to sex determination but they do affect the development of male characteristics.
Here is a breakdown of what male physical characteristics can be determined by genes on autosomal chromosomes:
- Height – men tend (but not always) to be taller than females
- Weight – men tend to be physically bigger and heavier
- Body shape – men would normally carry more muscle mass, have broader shoulders and narrower hips than women
- Hair – men tend to have more facial and body hair than women
Benefits of Testosterone
Testosterone is an anabolic hormone that stimulates fractional muscle protein synthesis to increase muscle mass. Testosterone may increase fats being broken down and has seen to reduce visceral fat.
The hormone is also necessary for male behavioral traits and the functioning of certain body systems. It promotes libido and helps with sperm production.
Testosterone deficiency may be linked with cognitive decline and even dementia. Some studies show that low levels of testosterone might be a risk factor for these illnesses.
Studies show that having higher testosterone levels can yield better cognitive performance in elderly men. There are also findings that demonstrate the benefits of testosterone supplementation for this subgroup's working memory and spatial cognition.
There is an association between testosterone and mood in men. Involution of the testes can lead to depressive moods, which may be improved by higher levels of testosterone. Some research suggests testosterone itself may have antidepressant properties.
Testosterone is also important for bone health. There is a correlation between an increased risk of osteoporosis and lower levels of testosterone.
It has been discovered that there are two main reasons for osteoporosis, for women it is an estrogen deficiency related to menopause, and age-related testosterone deficiency in men.
The ability to stay active, perform and work for long periods of time is called endurance. It usually refers to aerobic endurance. The cardiorespiratory system must be able to supply and use oxygen efficiently to maintain endurance performance. If it can't, your muscle activity will decrease and endurance will suffer.
Local muscle endurance is typically described as the ability to resist muscular fatigue and describes how a given type of contraction can be sustained, which is measured typically in the number of repetitions that can be maintained. Like aerobic endurance, muscular endurance also depends on a person's age and gender. Generally, total body endurance means having a strong heart & lungs so that oxygen can be delivered to working muscle.
Muscular fitness can encompass both muscle endurance and strength. As any physical activity requires at least some amount of muscular fitness to take place, it's important to consider improving your muscular fitness. This will make easier for you to complete mundane tasks all the while avoiding injury when doing more strenuous activities.
Exercise that improves cardiovascular endurance will also improve muscular endurance. Muscle endurance training provides a measurable, but small, improvement in muscle strength. As with any new fitness regimen, you'll need to apply the overload principle to see improvements in your endurance levels.
Activities where you use your muscles for a prolonged period is called endurance training. They include walking or running, cycling, resistance training, calisthenics, swimming, circuit training, aerobics, and dance.
There are many muscle endurance training protocols, however, in general, the load is relatively low, and the number of repetitions is high.
The main goal of endurance training is to increase your anaerobic threshold, which means you'll be able to train more efficiently. The factors affecting your VO2max may respond differently depending on the intensity or duration of the training, and even though genes are a factor in determining that number, they're not all-powerful.
Endurance is age sensitive, elite senior marathon runners can be in their 50s or 60s and show a decrease in endurance around the age of 50 years.
There are three types of endurance: aerobic, anaerobic lactic and anaerobic alactic. They all have their differences in metabolic processes.
What Effect does Testosterone have on Endurance?
Research has shown that chronic exposure to endurance athletes can cause issues to the physiological and endocrinological systems.
Excessive bouts of exercise affect the major male reproductive hormone, testosterone. Men who partake in chronic endurance exercise also tend to have lower levels of testosterone than those who don’t. This is often referred to as the; "exercise-hypogonadal male condition".
However, on the flip side, research has demonstrated that short-term, moderate intensity and low volume endurance training can significantly increase testosterone concentrations.
Recent research has found that increasing testosterone levels in the blood does lead to increased muscle mass and strength. This often means performance improvements for those in power and strength events.
There are limited studies on the subject, and it is difficult to ascertain a clear-cut picture regarding testosterone and its effect on endurance, this can be due to the ethical preposition of testing athletes, and their concerns of potential exclusion from competition.
However, there are some studies available that provide a positive outcome.
A paper published in the Frontiers in Physiology journal of December 2020 reported that testosterone improved endurance capacity in young, healthy women.
The paper demonstrated in tests that by increasing their testosterone levels by 4.8 times above baseline seemed to improve oxygen transport to the muscles, combined with an increased utilization of that oxygen by the muscles.
Another study published by The Journal of Clinical Endocrinology and Metabolism in 2009 concluded that testosterone has significant benefits for total and appendicular lean mass, muscle strength, and aerobic endurance in older men. There is also evidence to suggest it aids in weight loss.
A further study published a year later also came to similar conclusions regarding maximal oxygen increases.
Furthermore, as testosterone can increase the number of red blood cells and enhance oxygen levels, thus it would be assumed its actions can lead to better endurance. Afterall, it was addressed by the Senate that excess testosterone creates an advantage.
This advantage is illustrated by the retained performance advantages of transgender military service personnel who, even after 2+ years of hormonal therapy attained better running and push up scores than their female peers.
The Sport Journal concludes that testosterone results in abundant physiological effects that include improved aerobic endurance and faster recovery rates from high intensity exercise.
It must be noted, that athletic competitions are separated by gender, this is because of the physical advantages in strength, speed, and endurance that men have over women, which is partly due to testosterone.
How Can You Increase Testosterone?
There’s clearly a district performance advantage by having higher levels of testosterone, this is emphasised by the controversy of transgender athletes and the mere separate gender competition which is evident across most individual and team sports.
There’s also clear evidence that chronic endurance training can have a negative effect on testosterone levels, as such athletes, recreational or professional may wish to try and enhance or at least ‘normalize’ their testosterone levels, naturally.
So, let’s look at what we can do:
Well considered nutrition plays a huge role in overall health and performance of an athlete. Low energy availability (i.e., not consuming enough calories) is linked to extensive physiological disorders.
There’s also evidence that links dietary intake to hormonal status, this can be micro and macro nutrients as well as calories.
Check out our guide looking at the foods which can help stimulate testosterone production, here.
Resistance training has been proven to increase testosterone production in both young and elderly men.
We have written an article about weightlifting and its effects on testosterone that you can read, here.
Nutrition is a key part of your training routine; however, lifestyles, commitments and other obstacles sometimes get in the way. This means you can occasionally be in a position whereby you are eating convenience foods, or you don’t have the time (or the stomach) to eat everything that your body demands of you.
In these cases, a supplement can offer a beneficial and convenient way to ensure that you are not suffering from any deficiencies which can lead to a reduction in performance or illness.
There are plenty supplements that runners can take to improve performance, there are also natural and legal testosterone boosters available that contain clinically proven ingredients to enhance support testosterone production and also reduce inflammation that can be a result of hard training routines.
We all know the importance of sleep, for our mental and physical recovery, but that doesn’t always stop us from staying up far too late to watch that box set.
Yet, research shows that even one week of sleep restriction can reduce testosterone levels by 15%.
The military also recognise that 9% of accidents within the first Gulf War were attributed to lack of sleep whilst in charge of a vehicle.
There’s never been a better reason to get 8 hours of sleep per night!
While studies directly analyzing the effects of testosterone on endurance markers are limited there is some evidence particularly amongst female athletes and older males which does associate higher levels of testosterone with improved rates of endurance.
This is good to know for those who endure chronic training programs who are at risk of "exercise-hypogonadal male condition".
Aadditionally, we also know that testosterone is responsible for a number of positive health parameters such as bone health, mood, hemaglobin production, fat loss, recovery and muscle development.
Therefore, it is in your interests to support your natural testosterone production by getting rest, adequate nutrition and where suitable utilize supplements.