Men with strong, fast-swimming sperm may not only have better fertility, but also longer lives, a new study suggests. Researchers tracked more than 78,000 men over 50 years and found that those with higher sperm motility -- the ability of sperm to swim -- lived nearly three years longer than men with poor sperm movement. Advertisement "In absolute terms, men with a total motile count of more than 120 million (per milliliter of semen) lived 2.7 years longer than men with a total motile count of