Your Bones Are Alive! Learn How to Keep Them Strong

 

From VOA Learning English, this is the Health & Lifestyle report.

You may not realize it, but your bones are living tissue. And that tissue is always breaking down and re-growing.

When the growth of new bone tissue does not keep up with the loss of old bone tissue you may develop a medical condition called osteoporosis.

What is osteoporosis?

Osteoporosis literally¹ means "porous² bones." Normal bones have many tiny holes. With osteoporosis, the bones become so thin in places that even a simple stretch or a cough can result in a bone fracture.

Some fractures, like hip³ fractures, can lead to death. The National Center for Biotechnology Information in the United States says “some reports show that up to 50 percent of patients (in the U.S.) with hip fracture die within six months.”

Who will get osteoporosis?

About two hundred million people worldwide have osteoporosis. Health experts say that number will increase greatly as the world’s population gets older. After all, everyone's bones weaken with age.

The International Osteoporosis Foundation says that one in three women over the age of 50 will experience an osteoporotic fracture. The organization says for men over 50, the probability is one in five.

Usually people get osteoporosis as a result of hormonal⁴ changes, or from a lack of calcium⁵ or vitamin D. White and Asian people are at higher risk for the disease. Women are more likely to get it than men. Old people, small people and those with a family history of osteoporosis are also at higher risk for the disease.

There are behaviors that can help prevent osteoporosis. Eating healthful foods, being physically⁶ active and avoiding tobacco and alcohol use are important.

The importance of impact exercises

However, one of the most important things that will protect you against osteoporosis when you are older is how much bone mass you get when you are young.

The better your bone mass, the less likely you are to develop osteoporosis when you get older. According to several health websites, our bones are at their strongest between the ages of 20 to 30.

Bones, like muscles, react to pressure. When bones experience increased impact or force, they grow new cells.

So, it is important that children do high-impact activities like running, playing sports like basketball and volleyball and simple jumping. Jumping jacks⁸ and jumping rope are great exercises for a child’s bone growth. These impact exercises will help to build up bone mass needed later in life.

Not all exercises help your bones

As we said earlier, inactivity is bad for your bones. However, even people who exercise often can have low bone density⁹. This can lead to osteoporosis.

For example, meet bicyclist Dean Hargett. Every week, Hargett bikes more than 160 kilometers. This exercise is great for his heart, but it doesn't do much for his bones.

Hargett was surprised when the doctors told him that he had low bone density.

"It alarmed me. I don't want to have fragile bones. I want to be able to be strong and healthy throughout the rest of my life."

So, swimming and cycling might be great for your heart, but they do not do a lot for re-growing your bones. And even if you are very active and exercise often, that does not necessarily mean you have strong bones.

Pam Hinton is a researcher in nutrition, exercise and bone health at the University of Missouri in the United States.

Hinton studied how two kinds of exercises affected¹⁰ men’s bone health: resistance and jump-training. Resistance training is a form of exercise in which you work against force. The study took place over a 12-month period. The results showed that resistance exercises did more than just slow the rate of bone loss.

"We actually saw an increase in bone mass with either type of exercise, so that was a very encouraging and exciting result."

Bicyclist Dean Hargett is encouraged by the news. He now knows he has to do more than cycle to stay healthy.

He also has a warning -- do not take bone strength for granted. In other words, do not make the mistake of thinking your bones are always going to be strong and healthy.

"Don't take your bone strength for granted. They can wither¹¹ just like any other part of your body."

Exercises and food for healthy bones

So, to help your bones stay healthy, the National Osteoporosis Foundation in the U.S. suggests doing weight-bearing and muscle-strengthening exercises.

Examples of high-impact weight-bearing exercises are:

- dancing

- hiking

- jogging/running

- jumping rope (other sites suggest simply jumping in place)

- stair climbing and

- tennis

For muscle-strengthening exercises, they suggest:

- lifting weights

- using weight machines

- and lifting your own body weight.

And remember, what you put into your body matters too.

Get enough calcium and vitamin D. New research shows that vitamin K may also be good for your bones. Good sources of K include dark leafy greens such as kale and spinach¹².

Lower your salt use, too. Avoid soda¹³ and too much alcohol as well. Both can affect how your body uses calcium. And, if you smoke, quit.

That’s the Health & Lifestyle report.

Words in This Story

literally – adv. in a completely accurate way a story that is basically true even if not literally true

fracture – n. the act or process of breaking or the state of being broken; especially : the breaking of hard tissue (as bone)

impact – n. the act or force of one thing hitting another

jumping jack⁷ – n. an exercise in which a standing¹⁴ person jumps to a position with the legs and arms spread out and then jumps back to the original position

alarm – v. to strike with fear

fragile – adj. easily broken or destroyed a fragile vase fragile bones

encourage – v. to inspire with courage, spirit, or hope

hormone¹⁵ – n. a natural substance that is produced in the body and that influences the way the body grows or develops

wither – v. to become dry and sapless; especially : to shrivel from or as if from loss of bodily moisture

soda – n. US : a drink made of soda water, flavoring, and some type of sugar

1 literally   

adv.照字面意义，逐字地；确实

参考例句：

• He translated the passage literally.他逐字逐句地翻译这段文字。
• Sometimes she would not sit down till she was literally faint.有时候，她不走到真正要昏厥了，决不肯坐下来。

2 porous   

adj.可渗透的，多孔的

参考例句：

• He added sand to the soil to make it more porous.他往土里掺沙子以提高渗水性能。
• The shell has to be slightly porous to enable oxygen to pass in.外壳不得不有些细小的孔以便能使氧气通过。

3 hip   

n.臀部，髋；屋脊

参考例句：

• The thigh bone is connected to the hip bone.股骨连着髋骨。
• The new coats blouse gracefully above the hip line.新外套在臀围线上优美地打着褶皱。

4 hormonal   

adj.激素的

参考例句：

• Some viral diseases are more severe during pregnancy, probably tecause of hormonal changes. 有些病毒病在妊娠期间比较严重，可能是由于激素变化引起的。
• She underwent surgical intervention and a subsequent short period of hormonal therapy. 他接受外科手术及随后短暂荷尔蒙治疗。

5 calcium   

n.钙(化学符号Ca)

参考例句：

• We need calcium to make bones.我们需要钙来壮骨。
• Calcium is found most abundantly in milk.奶含钙最丰富。

6 physically   

adj.物质上，体格上，身体上，按自然规律

参考例句：

• He was out of sorts physically,as well as disordered mentally.他浑身不舒服，心绪也很乱。
• Every time I think about it I feel physically sick.一想起那件事我就感到极恶心。

7 jack   

n.插座，千斤顶，男人；v.抬起，提醒，扛举；n.（Jake）杰克

参考例句：

• I am looking for the headphone jack.我正在找寻头戴式耳机插孔。
• He lifted the car with a jack to change the flat tyre.他用千斤顶把车顶起来换下瘪轮胎。

8 jacks   

n.抓子游戏；千斤顶( jack的名词复数 )；（电）插孔；[电子学]插座；放弃

参考例句：

• Hydraulic jacks under the machine produce the movement. 是机器下面的液压千斤顶造成的移动。 来自《简明英汉词典》
• The front end is equipped with hydraulic jacks used for grade adjustment. 前瑞安装有液压千斤顶用来调整坡度。 来自辞典例句

9 density   

n.密集，密度，浓度

参考例句：

• The population density of that country is 685 per square mile.那个国家的人口密度为每平方英里685人。
• The region has a very high population density.该地区的人口密度很高。

10 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

11 wither   

vt.使凋谢，使衰退，(用眼神气势等)使畏缩；vi.枯萎，衰退，消亡

参考例句：

• She grows as a flower does-she will wither without sun.她象鲜花一样成长--没有太阳就会凋谢。
• In autumn the leaves wither and fall off the trees.秋天，树叶枯萎并从树上落下来。

12 spinach   

n.菠菜

参考例句：

• Eating spinach is supposed to make you strong.据说吃菠菜能使人强壮。
• You should eat such vegetables as carrot,celery and spinach.你应该吃胡萝卜、芹菜和菠菜这类的蔬菜。

13 soda   

n.苏打水；汽水

参考例句：

• She doesn't enjoy drinking chocolate soda.她不喜欢喝巧克力汽水。
• I will freshen your drink with more soda and ice cubes.我给你的饮料重加一些苏打水和冰块。

14 standing   

n.持续，地位；adj.永久的，不动的，直立的，不流动的

参考例句：

• After the earthquake only a few houses were left standing.地震过后只有几幢房屋还立着。
• They're standing out against any change in the law.他们坚决反对对法律做任何修改。

15 hormone   

n.荷尔蒙，激素，内分泌

参考例句：

• Hormone implants are used as growth boosters.激素植入物被用作生长辅助剂。
• This hormone interacts closely with other hormones in the body.这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。