日批在线视频_内射毛片内射国产夫妻_亚洲三级小视频_在线观看亚洲大片短视频_女性向h片资源在线观看_亚洲最大网

Boys today may be hitting puberty earlier

(Agencies)
Updated: 2010-12-07 11:29
Large Medium Small

Boys today may be on a faster track to puberty than their fathers' generation, reaching the milestone an average of a year earlier, according to a study conducted in Bulgaria.

The findings suggest that trends toward earlier puberty aren't limited to girls, who have already been shown to be developing sexually at increasingly younger ages.

In the study, reported in the Archives of Pediatrics and Adolescent Medicine, researchers from Cedars Sinai Medical Center in Los Angeles compared 6,200 healthy Bulgarian boys with a similar 1970s study. Both measured height, weight, testicular volume, penis length and circumference.

"Studies done several decades ago in the same population reported that a leap forward in sexual development occurs at ages 13 through 16," said Fnu Deepinder, who led the study, in an email to Reuters Health.

"However, our study indicated that this spurt takes place between 12 and 15 years old."

Deepinder and his colleagues found that boys' testicles did not grow substantially until the beginning of puberty, around age 11. But penises appeared to grow gradually from birth to sexual maturity, starting at around 5 cm (2 inches) and reaching an average length of nearly 9.5 centimeters (4 inches) by the age of 19.

However, both penises and testicles grew most rapidly between ages 12 to 16, while boys added the most inches in height and gained the most weight between 12 and 14 years gold.

The study also found that while boys of the same age in the 1970s study had relatively smaller genitalia, men are not necessarily more well-endowed today, with size differences disappearing by age 17.

Boys in rural areas had slightly longer penises than their urban peers, although the difference was only about 0.4 cm (0.2 inches).

Deepinder said that genetic, environmental, nutritional and educational factors could all be behind the faster development today, but it remains unclear what impact earlier puberty might have on men's health.

It also remains unclear whether specific differences exist between populations from different parts of the world.

主站蜘蛛池模板: 97香蕉久久夜色精品国产 | 国产www在线 | 日批视频在线 | 奇米色888| 少妇日韩 | 国产aⅴ | 一级黄色片a| 宅男午夜影院 | 美女一区二区三区四区 | 国产一区二区久久 | 日韩欧美国产综合 | 亚洲综合精品在线 | 精品色 | 欧美成人短视频 | 成人毛片在线免费观看 | 成人国产免费 | 成人午夜免费福利视频 | www.日韩在线| 日韩黄色在线视频 | 99精品视频在线播放免费 | 免费观看毛片网站 | 欧美肥老太wbwbwbb | 天天操夜夜爽 | 日韩中文字幕一区二区 | 在线观看免费视频一区 | www.精品一区 | 不卡视频一区 | 日韩影视一区 | 精品一区二区三区三区 | 国产又黄又爽又色 | 天堂网中文在线 | 精品一区二区三区四区五区六区 | 久久久福利视频 | 99热综合| 久久精品高清 | 免费欧美一级片 | 91福利小视频 | 天天操夜夜逼 | 哪里看毛片 | 激情视频一区二区三区 | 久操精品视频 |