Guys who cycle regularly are skinny, in shape and oh-so attractive to the ladies.

Except that the time spent bounding on that bicycle seat turns out to be not so good for a dude's reproductive health. Just another danger for those who prefer peddle power in L.A.

And the problem isn't just with all that equipment bouncing around. UCLA researchers found that men who ride a lot end up producing more of a form of estrogen, and the results can include …

… loss of pubic hair and larger man-boobs. Yep.

The academics looked at 107 men, including 46 cyclists and 61 who were triathletes and recreational athletes of other stripes.

The bike riders saw levels of estradiol, the form of estrogen, that were “more than two times higher in cyclists than in triathletes and recreational athletes,” according to the study published recently in the European Journal of Applied Physiology. (Laura Perry of UCLA School of Nursing sent us a copy.)

The cyclists also saw elevated testosterone, but much lower levels of other important sex-related hormones.

What does this all mean — that male bike riders are wussies with sexy legs?

Nooo.

The researchers conclude that the data …

… suggest that despite well-known positive effects associated with exercise, specific types of exercise may be associated with altered sex hormone levels in men that could affect general health and reproductive well being.

Maybe try running more?

[@dennisjromero / djromero@laweekly.com / @LAWeeklyNews]

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