Private MD News

Intense physical training may damage sperm

Category: Infertility Testing-Male

Training for international-level competitions such as triathlons may contribute to infertility because of damage to sperm quality, according to a study reported at the 25th annual conference of the European Society of Human Reproduction and Embryology.

The researchers, led by Professor Diana Vaamonde, from the University of Cordoba Medical School in Spain, were unable to isolate a single factor at the root of the problem. Vaamonde noted that the triathletes who did the most cycling training had the most damaged sperm.

Previous studies by the researchers have found that both high exercise intensity and high exercise volume may be detrimental to sperm quality. In this study they found that only cycling showed a clear correlation with sperm quality.

"The fact that this effect is greater in triathletes than in other sports practices seems to indicate that it is something to do with the volume of training that they need to undertake to achieve and maintain a high level of fitness," said Vaamonde.

Semen tests of the Spanish triathletes found that all of them had less than 10 percent of normal-looking sperm, with even lower levels in those who did the most cycling training.