Bicycle Warnings For Men—Reproductive Health Could be Jeopardized

Researchers say in a UCLA School of Nursing study that men who ride bicycles may experience hormonal imbalances.

Men who ride bicycles may experience hormonal imbalances that could affect their reproductive health, researchers say in a UCLA School of Nursing study released today.

To date, an extensive amount of research has been performed documenting
the positive effects of long-term exercise on health, according to a nursing
school statement.

These studies have shown that while moderate exercise can lead to

enhanced cardiovascular and metabolic function and reduced body fat, ultra-
endurance levels of exercise can also adversely affect the neuroendocrine
system and reproductive health,'' the statement said.

The UCLA study explored the associations between exercise intensity and
circulating levels of reproductive hormones in serious leisure male athletes --
triathletes and cyclists -- and recreational athletes.

UCLA researchers, according to the nursing school statement, studied 107 healthy male athletes ages 18 to 60 and divided them into three groups: 16 were triathletes, 46 were cyclists and 45 were recreational athletes. Blood samples were collected from each participant to measure total testosterone, estradiol, cortisol, interleukin-6 and other hormones.

"Plasma estradiol and testosterone levels were significantly elevated in serious leisure male cyclists, a finding not previously reported in any type of male athlete,'' said School of Nursing assistant professor Leah Fitzgerald, the study's senior author.

Plasma estradiol concentrations were more than two times higher in the cyclists than in the triathlete and recreational athletes, and total testosterone levels were about 50 percent higher in cyclists than in the recreational athletes, she said, adding: These effects were accompanied by little or no compensatory shift in circulating reproductive hormone levels.''

Estradiol is a form of estrogen and produced in males as an active metabolic product of testosterone. Possible conditions associated with elevated estrogen in males include gynecomastia, which can result in the loss of male pubic hair and enlarged breast tissue.

Although preliminary, these findings warrant further investigation to determine if specific types of exercise may be associated with altered sex hormone levels in men that could affect general health and reproductive well-being,'' Fitzgerald said.

The study also found an association between an increase in estrogen levels and of chamois cream use, particularly for male cyclists using the cream for more than four years. But no direct cause and effect has been established, the statement said. The cream is applied to help prevent chaffing and bacterial infections related to bicycle saddle sores.

The UCLA study, "Reproductive Hormones and Interleukin-6 in Serious
Leisure Male Athletes,'' was published in the European Journal of Applied
Physiology. It was funded by the UCLA School of Nursing, UCLA General Clinical
Research Center and the nonprofit Kaiser Foundation.

--City News Service

MKC May 22, 2012 at 05:22 AM
Exercise is not the root cause of the hormonal imbalances. Age and physiology are the predominant factors for hormone levels in males. This "report" does not adequately address all variables associated with imbalances and attempts to single out a cause without a genuine basis.
Ann D May 22, 2012 at 05:04 PM
A good portion of these riders take over the road with no regard for the cars that are driving in the lanes. Maybe it's best such selfishness does not reproduce. :-)
Ann D May 22, 2012 at 06:26 PM
My comment does not get approved because I said alot of these riders are selfish and don't care about the cars that are in the lanes and maybe such selfish people shouldn't reproduce??? So much for free speech Patch.
David Huntsman May 23, 2012 at 05:32 PM
How would that work?
T.Spayede May 26, 2012 at 03:46 AM
...Always wondered what those sister ucla nurses were doing with their downtime...Yu go girls! Any word on what the Trojan girls are up to, downtown?...Such studies must show some serious intent going on...Perhaps there is work in progress on what the lady bikers are experiencing, too ( - there must be something addressing the wearing of pedalpushers that may be popping up soon...?) Interesting...science.


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