American children aren't the only couch potatoes with nearly one third of children globally spending three hours a day or more watching TV or on computers, according to study of over 70,000 teens in 34 nations.

From Argentina to Zambia, Regina Guthold of the World Health Organization in Geneva and her colleagues found most children aren't getting enough exercise and it made no difference if they lived in a rich or a poor country.

"With regards to physical activity levels, we did not find much of a difference between poor and rich countries," Guthold said. "Growing up in a poor country does not necessarily mean that kids get more physical activity."

The study, published in The Journal of Pediatrics, looking at 72,845 schoolchildren aged¹ 13 to 15 from North and South America, Asia, Europe, and the Middle East. The children were surveyed between 2003 and 2007.

The researchers defined adequate physical activity as at least an hour of exercise outside of gym class at least five days a week.

Children who spent three or more hours a day watching TV, playing computer games, or chatting with friends -- aside from time in school or time spent doing homework -- were classified as sedentary.

The researchers found only one quarter of the boys and 15 percent of the girls were getting enough exercise by these definitions.

A quarter of boys and nearly 30 percent of girls were sedentary and didn't get enough exercise with girls less active than boys in every country aside from Zambia.

Uruguay had the highest percentage of active boys, at 42 percent, while Zambia had the lowest, at 8 percent.

Girls from India were the most active, with 37 percent meeting exercise recommendations, while girls from Egypt were the least active, with just 4 percent getting adequate exercise.

Children in Myanmar were the least sedentary, with 13 percent of boys and 8 percent of girls classified as sedentary. The most sedentary nations were St. Lucia and the Cayman Islands, with 58 percent of boys and 64 percent of girls spending at least three hours a day in sedentary activities.

While the study didn't look at the reasons behind the lack of physical activity in various nations, Guthold speculated that urbanization could be a factor as well as access to cars and TVs.

一项面向34个国家7万多名青少年开展的调查显示，爱泡在电视机前的并非只有美国儿童，全球近三分之一的儿童每天看电视或玩电脑的时间达到三小时甚至更多。

位于日内瓦的世界卫生组织的瑞吉娜•古特尔德和她的同事发现，从阿根廷到赞比亚，全球多数儿童都缺乏锻炼，而且这和他们生活在富国和穷国没有多大关系。

古特尔德说：“在身体锻炼水平上，我们发现穷国和富国的孩子没有太大差别。在贫穷国家长大，并不意味着能得到更多的锻炼。”

该研究在《儿科学期刊》上发表。研究人员于2003年至2007年间对南北美洲、亚洲、欧洲和中东地区年龄在13岁到15岁之间的72845名学生进行了调查。

研究人员将“充足的身体锻炼”定义为每周至少锻炼五天，每天至少进行一小时的户外锻炼。

除了在学校或做作业的时间外，每天看电视、玩电脑游戏或和上网聊天的时间超过三小时的孩子被定义为”惯于久坐”。

研究人员发现，根据这些定义，只有四分之一的男孩和15%的女孩进行了足够的锻炼。

四分之一的男孩和近30%的女孩“惯于久坐”，缺乏锻炼。除赞比亚外，所有国家的女孩都不如男孩爱动。

乌拉圭爱活动的男孩比例最高，达到42%，赞比亚的这一比例最低，只有8%。

印度女孩最活跃，其中有37%达到建议活动量，埃及的女孩最不爱动，只有4%进行了足够的锻炼。

缅甸的“久坐型”儿童最少，只有13%的男孩和8%的女孩惯于久坐。圣卢西亚和开曼群岛的儿童最惯于久坐，58%的男孩和64%的女孩每天坐着的时间至少为三个小时。

尽管这一研究没有探究各国儿童缺乏身体锻炼的背后原因，但据古特尔德分析，除汽车和电视的普及外，都市化也是其中一个因素。