Amsterdam - Intensive professional cycling training damages
sperm, according to a study presented at the annual conference of the
European Society of Human Reproduction and Embryology in Amsterdam
recently.
Professor Diana Vaamonde, affiliated with the Spanish University
of Cordoba Medical School, found that high-intensity training by
triathletes significantly diminishes the quality of their sperm.
Previous studies by Vaamonde's team had already shown that both
high exercise intensity and high exercise volume might be detrimental
to sperm quality.
In the new study, in which the research team thoroughly analyzed
the sperm quality of 15 triathletes with an average age of 33, the
scientists found a direct correlation between the volume of training
in each activity and sperm quality.
Of the three modalities, only cycling, the activity for which
triathletes undertake the most training, showed a clear correlation
with sperm quality. The more time and distance covered in cycling,
the worse sperm quality became.
'We found a statistically adverse correlation between sperm
morphology and the volume of cycling training undertaken per week,'
Vaamonde said.
The scientists say that the reduced sperm quality is most likely
caused by a number of factors. Irritation and compression caused by
friction of the testes against the saddle or the localized heat
produced by wearing tight clothing might explain part of the problem.
But, the study says, reactive oxygen species - small molecules
that are a natural by-product of oxygen metabolism and which react to
stress by increasing to such an extent that they can damage cell
structures - and energetic imbalances may play an important role in
the sperm alterations.
Vaamonde said it was necessary to develop 'protective measures'
for professional sportsmen to prevent damage to their sperm quality,
including freezing their sperm prior to intensive training
programmes.
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