Does Running, Cycling or Swimming Kill Testosterone? How To Deal with It!

The testosterone formed in the testicles plays a significant role in the normal development and functioning of male sexual features.

These male sexual features include; the growth of body and facial hair, the deepening of the male voice, the growth of testicles, the production of sperm, and an increase in muscle strength. Testosterone also helps increase the red blood cell count and improve bone health. 

Teen boys experience rapid growth and development due to the rise in their testosterone level during puberty, but as they get older, testosterone levels decrease. 

Note that getting older is not the only reason for a decrease in testosterone levels, and activities such as cycling can kill the testosterone level because of the excess pressure the bike saddle puts on the scrotal sac where the testes lie. 

You might be wondering if swimming and running also have the same effect on testosterone levels ?!

Does Cycling Kill Testosterone?

Cycling is an activity that puts excessive stress on the body, especially around the scrotal sac that contains the testicles. Cycling for long periods puts the testicular nerves and blood vessels at risk of getting constricted due to the pressure from the saddle of the bike. When that happens, such cyclists are bound to experience pain and discomfort. There is also a high probability of a rapid decrease in testosterone production because of the temperature dysregulation within the scrotal sac.

The scrotal sac ought to be at a specific temperature to aid testosterone production, but it becomes hot when inflamed. 

Another reason cycling could kill testosterone is that it is a high-endurance sport that causes an increase in cortisol which counteracts the effect of testosterone. Research done in 2005 by J Sports Sci Med confirmed this negative correlation after the intake of cortisol caused a decrease in blood testosterone levels. (Source)

A low testosterone level is advantageous to cyclists as there is no buildup of extra muscle that might slow you down, but if you already have a low testosterone level, you should avoid cycling.

Does Swimming Kill Testosterone?

Swimming produces the exact opposite effect to the level of testosterone when compared to cycling. A research experiment performed by Jordan University of Science & Technology on highly active and moderately active rats showed a direct correlation between swimming and sexual performance. The research concluded that swimming enhances mating behavior which interprets a rise in the testosterone level. (Source

Does Running Kill Testosterone?

Running has the same effect on testosterone levels as cycling, but it doesn’t produce the same intense effect. This means that the decrease in testosterone level is not enough to cause a decline in the development and functioning of the sex organs.

Just like in cycling, the testosterone decrease is beneficial to the athletes because there is no buildup of muscles that could slow down the athletes.

Which Sport Decreases Testosterone the Most?

Testosterone decrease usually happens due to the exertion of excess stress on the body. Although cycling and running tend to cause low testosterone levels, cycling decreases testosterone levels the most. (Source)

Cycling and running are activities that cause the body stress and excite the endocrine system to redirect the production of hormones to the most vital organs leaving out organs like the reproductive organs. For this reason, testosterone reduces drastically.

What Are the Signs of Low Testosterone?

One of the major signs of low testosterone is having reduced blood cell count, especially the red blood cells, which eventually results in more complications. These complications include fatigue, lack of memory and concentration, lack of muscular strength, restlessness, and irritability.

Other symptoms that could arise with low testosterone include;

  • Low libido
  • Decreases bone density
  • Increase body fat
  • Breast development 
  • Erectile dysfunction 
  • Infertility
  • Sleeping problems

What Sport Increases Testosterone Most?

Swimming and weightlifting are exercises that tend to improve testosterone level but based on research, lifting heavy weights boost testosterone more. 

When you lift heavy weights, you not only improve your metabolism or strengthen your body, but the body is triggered to produce more testosterone. (Source

How Can I Boost My Testosterone Fast?

The best and safe way to increase your testosterone fast is through natural ways and some of these include: (Source)

Engaging in regular exercise such as weightlifting

Exercises such as weight lifting play a major role in boosting muscle growth that leads to an increase in testosterone levels. This increase is more evident in men who exercise regularly and lift heavy weights that target a larger muscle group than just a single muscle group.

There are many more exercises asides from weightlifting that causes a rise in testosterone level but be careful not to engage in high endurance exercises like cycling.

Eating a well-balanced meals (with all basic nutrients)

Food is everything especially when it comes down to the production of body hormones. Your everyday meals should contain a well-balanced proportion of all the basic nutrients such as proteins, carbohydrates, fruits, and vegetables to help boost testosterone production.

Here are ways these nutrients lead to a rise in testosterone hormone:

Protein stimulates muscle gain that promotes testosterone production.

Carbohydrate helps to lower cortisol level, thereby allowing the production of the testosterone hormone.

Fruits and vegetables increase testosterone levels indirectly by flushing the body of estrogen hormone.

Taking your multivitamin supplements regularly

Your everyday meals are not enough to give your body the boost it needs to produce more testosterone. For this reason, it is advisable to incorporate vitamin and mineral supplements such as vitamin D, zinc, and calcium supplements.

Research has proven that these supplements are good testosterone hormone boosters, especially in the elderly (source).

An alternative to taking vitamin D supplements is to expose yourself to sufficient sunlight.

Minimizing your stress levels and cutting down on the intensity of exercise

Stress leads to excessive production of cortisol in the body which negatively impacts testosterone production. To avoid stress in your everyday life, you should adopt a healthy lifestyle that creates a balance between rest and work.

You can incorporate rest in your everyday living by creating and sticking to a daily routine, Getting at least 7-8 hours of sleep daily, Cutting down on the intensity of workout/exercise, etc.


Out of the three triathlon sporting events, cycling kills testosterone the most, followed by running. Cycling decreases testosterone levels because it is a high endurance exercise that causes stress and rapid production of cortisol, a hormone that dampens testosterone production.

Cycling also prevents testosterone production by causing a temperature dysregulation within the scrotal sac due to the pressure mounted on it. Nevertheless, swimming and weightlifting are good boosters of testosterone levels.

Note that weightlifting is not part of the triathlon sport, but you can engage in it if you have a low testosterone level.


A medical student with passion in health and sports-related topics that discuss the optimization of one’s overall health through healthy nutrition, fitness, and adequate rest

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