Extensive evidence shows the impact of diet and lifestyle on male fertility. The most important factors to take into account are the following:
It has been shown that smoking diminishes both the sperm count and its motility.
The excessive consumption of alcoholic drinks affects the quality of the sperm. There is no evidence about the effects of moderate consumption of alcohol on sperm.
The use of illegal drugs clearly diminishes the quality of the sperm. It should be strictly avoided. If you are using prescription drugs, ask you doctor or pharmacist for advice.
For successful renewal of sperm, it is recommended having regular sexual relations, even if the woman is not in her "most fertile week".
No scientific evidence exists about the best "position" for pregnancy.
Excessive heat and tight fitting underwear:
The testicles should be at a lower temperature than the rest of the body to optimise the production of sperm. For this it is recommended not to subject the testicles to excessive heat (avoid lengthy baths in hot water and using laptops directly on your lap).
There is no scientific evidence on whether the use of "boxer" type of underwear is better than the "slip" type. Either way, to prevent excessive heat, tight fitting underwear is not recommended.
A balanced diet is recommended, with extra intake of vegetables and fruits, together with the consumption of sufficient liquid. Men should avoid consuming large quantities of products containing soya because they can contain small quantities of phytoestrogens.
Moderate physical exercise is beneficial for the quality of the sperm. But excessive physical exercise can be as bad as not doing any physical activity.
It is recommended limiting the consumption of caffeine drinks to 1 or 2 per day.
If you work or are exposed to environmental toxins (such as pesticides, organic solvents, fumes or radiation), you could be damaging the quality of your sperm.