Impossible. Only chemicals can do that.
“Men’s sperm quality may be significantly affected by their levels of physical activity, according to a new study led by researchers at Harvard School of Public Health (HSPH). They found that healthy young men who were sedentary, as measured by hours of TV viewing, had lower sperm counts than those who were the most physically active. “We know very little about how lifestyle may impact semen quality and male fertility in general so identifying two potentially modifiable factors that appear to have such a big impact on sperm counts is truly exciting,” said lead author Audrey Gaskins, a doctoral student at HSPH. The study will be published online February 4, 2013 in the British Journal of Sports Medicine.” [EurekAlert]