A new study conducted by researchers at the University of Cordoba links moderate physical activity in males with better hormone levels and sperm characteristics that favour reproduction compared to sedentary men.

Semen quality at large has dropped in the last 50 years. Amongst other factors, this is due to exposure to external agents and alcohol and tobacco consumption. This decline in sperm properties has caused an increase in reproductive problems.

Therefore, experts have studied the possible relationship between sperm quality and lifestyle habits in males. Published in the 'European Journal of Applied Physiology', the new study suggests that men who do moderate physical exercise have better hormone levels and their gonads undergo healthier spermatological processes.

The authors assessed whether there was a difference in the hormonal and seminoligical profiles of physically active and sedentary males. "We have analysed qualitative semen parameters like the ejaculated volume, sperm count, mobility and sperm morphology," as explained by Diana Vaamonde, researcher at the University of Cordoba and lead author of the study.

In addition, an evaluation was made of the follicle-stimulating hormone (FSH), the luteinising hormone (LH), testosterone (T), cortisol (C) and the T/C ratio. This offers additional information on the environment needed for the sperm creation process as well as the anabolic or catabolic state of the body.

"Despite the fact that the sample population is not very big (31 men), given the complexity of the analysis, this is the first study that assessed the differences between these parameters in both populations," states the researcher.

The results conclude that the physically active subjects display better semen values. More specifically, the differences found were in the seminological parameters of total progressive velocity and morphology, in the FSH, LH and T hormones and in the T/C ratio. Hormone data thus supports the hypothesis of a more favourable environment for sperm formation.

Moderate exercise is the key

In 2010, the same researcher published a study showing that the sperm parameters of elite sportsmen (triathletes and waterpolo players) are worse than men who are just physically active. It is possible that the increased strain of training causes a decline in sperm quality.

"Despite that fact that more studies are needed to confirm these findings, we can suggest exercise to improve the hormonal environment and stimulate the sperm process," adds Vaamonde.

Sperm quality parameters

According to the 'Manual for the examination of human semen and semen-cervical mucus interaction' published in 2010 by the World Health Organisation (WHO), the most frequently examined parameters in a seminogram for evaluating semen quality are:

Liquefaction: After ejaculation the semen coagulates and needs to be liquefied for its study. Under normal conditions the semen stays liquefied for a total of 60 minutes after ejaculation.

Viscosity: If the sample is very viscous, this could be down to a prostate dysfunction.

Volume: The normal volume of an ejaculate after 3 to 5 days of abstinence is approximately 1.5 ml. A lower value is called hypospermia.

Colour: Semen is normally an opalescent, slightly yellow colour. When colour is slightly different, the possible cause should be studied.

pH: This value should be above 7.1. Lower values could be a sign of azoospermia (absence of spermatozoids) or chronic inflammatory processes.

Spermatozoid concentration: The normal value is 15 million for each ml of ejaculate or 39 million in the entire sample. If these values are not reached, this is a case of oligozoospermia.

Motility: The percentage of mobile spermatozoids and those with progressive motility (those that are mobile yet travel) is assessed. Motility is considered normal when at least 32% of spermatozoids have progressive motility. If not, this is called astenozoospermia.

Vitality: The percentage of living spermatozoids should exceed 58%. Any lower and this is called necrozoospermia.

Morphology: Examples can be seen of both normal spermatozoids and those with different abnormalities, whether in the head or the tail. Semen considered normal should have 4% or more of normal spermatozoids. Cases in which this value is lower are called teratozoospermia.

Leukocytes: If leukocyte concentration is higher than 1 million per ml of sample, this could indicate an infection (leukocytosis).

Antisperm antibodies or Mar test: This reflects the quantities of spermatozoids joined to other cells or particles. If more than 50% of spermatozoids are found joined in this way, this could suggest an immune problem.

Furthermore, the latest WHO manual establishes the concept of the "lower reference limit" (LRL). Those values found above the limit do not guarantee successful fertilization and subsequent pregnancy, but chances increase. The LRL has been on the decline over the years due to general social habitats and new lifestyle characteristics such as diet, tobacco, environmental toxins, etc.