What do extreme marathoners, mountain hikers and professional bicycle racers all have in common? They push their bodies to unsustainable (不可持续的) extremes of physical stress.
We tend to think there’s no limit to human physical achievements. But a new study, published in Science Advances, says there is a definite limit to human endurance (耐力). Beyond that, our bodies begin to break down.
To find the limit, a US research team tracked marathon runners over a five-month period, measuring competitors’ initial basal metabolic rates (BMR, 基础新陈代谢率) – the amount of energy they expend when they rest. Then they looked at how many calories(卡路里) each runner burned per day.
The team found that the maximum amount of energy a human can expend is 2.5 times of BMR. It equals 4,000 calories of energy per day. These calories can help a trained athlete to run about 42 kilometers in a day.
But people can’t keep using this amount of calories all the time. “You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back,” US evolutionary anthropologist Herman Pontzer told the BBC.
Pontzer explained that the problem is our guts (消化道). “There’s … a limit to how many calories our guts can effectively absorb per day,” he said in the Daily Mail. At that point, the body is burning calories more quickly than it can absorb food and convert (转化) it into energy.
These new findings could help athletes to best work underneath this ceiling. For example, they could manage their daily exercise time based on their BMR, to get enough calories and keep going.
However, Pontzer’s team can’t rule out the possibility of someone breaking this limit. “So I guess it’s a challenge to elite endurance athletes,” said Pontzer. “Science works when you’re proven wrong. Maybe someone will break through that ceiling some day and show us what we’re missing.”
1.What did the US research team find in the new study?
A.One’s endurance can be improved through exercise.
B.A trained athlete can do intense activities for more than a week.
C.The average BMR for athletes is 4,000 calories of energy per day.
D.The energy one can expend is no more than 2.5 times of their BMR per day.
2.What is the main purpose of Paragraph 6?
A.To tell us the problem with our guts.
B.To show how our bodies produce energy.
C.To explain why there is a limit to human endurance.
D.To prove the importance of our guts to physical activities.
3.The new findings could help athletes ______.
A.keep a more balanced diet
B.save time and reduce stress
C.arrange their training properly
D.improve their performance quickly
4.Which of the following would Pontzer probably agree with?
A.It’s possible that someone could break the endurance limit.
B.It’s no good trying to work above the 2.5x endurance ceiling.
C.Further data is needed to make the study’s results more accurate.
D.The 2.5x endurance ceiling is not a problem for many elite athletes.
高三英语阅读理解中等难度题
What do extreme marathoners, mountain hikers and professional bicycle racers all have in common? They push their bodies to unsustainable (不可持续的) extremes of physical stress.
We tend to think there’s no limit to human physical achievements. But a new study, published in Science Advances, says there is a definite limit to human endurance (耐力). Beyond that, our bodies begin to break down.
To find the limit, a US research team tracked marathon runners over a five-month period, measuring competitors’ initial basal metabolic rates (BMR, 基础新陈代谢率) – the amount of energy they expend when they rest. Then they looked at how many calories(卡路里) each runner burned per day.
The team found that the maximum amount of energy a human can expend is 2.5 times of BMR. It equals 4,000 calories of energy per day. These calories can help a trained athlete to run about 42 kilometers in a day.
But people can’t keep using this amount of calories all the time. “You can do really intense stuff for a couple of days, but if you want to last longer then you have to dial it back,” US evolutionary anthropologist Herman Pontzer told the BBC.
Pontzer explained that the problem is our guts (消化道). “There’s … a limit to how many calories our guts can effectively absorb per day,” he said in the Daily Mail. At that point, the body is burning calories more quickly than it can absorb food and convert (转化) it into energy.
These new findings could help athletes to best work underneath this ceiling. For example, they could manage their daily exercise time based on their BMR, to get enough calories and keep going.
However, Pontzer’s team can’t rule out the possibility of someone breaking this limit. “So I guess it’s a challenge to elite endurance athletes,” said Pontzer. “Science works when you’re proven wrong. Maybe someone will break through that ceiling some day and show us what we’re missing.”
1.What did the US research team find in the new study?
A.One’s endurance can be improved through exercise.
B.A trained athlete can do intense activities for more than a week.
C.The average BMR for athletes is 4,000 calories of energy per day.
D.The energy one can expend is no more than 2.5 times of their BMR per day.
2.What is the main purpose of Paragraph 6?
A.To tell us the problem with our guts.
B.To show how our bodies produce energy.
C.To explain why there is a limit to human endurance.
D.To prove the importance of our guts to physical activities.
3.The new findings could help athletes ______.
A.keep a more balanced diet
B.save time and reduce stress
C.arrange their training properly
D.improve their performance quickly
4.Which of the following would Pontzer probably agree with?
A.It’s possible that someone could break the endurance limit.
B.It’s no good trying to work above the 2.5x endurance ceiling.
C.Further data is needed to make the study’s results more accurate.
D.The 2.5x endurance ceiling is not a problem for many elite athletes.
高三英语阅读理解中等难度题查看答案及解析
Last Sunday, Aron Ralston, an experienced hiker and mountaineer, set off to walk alone through the Bluejohn desert canyon (峡谷) in Utah. He was planning an eight-hour, 21–kilometer hike. While he was climbing through a narrow part of the canyon, a big stone weighing about 400 kilos fell and trapped his right arm.
When he failed to return to the mountain camp where he was staying that night, people simply thought he had decided to camp out somewhere in the canyon. When he still had not returned by Tuesday, the alarm was raised, A search party set out on Wednesday evening, but there we no sign and his family began to fear the worst.
In fact, Ralston, 27, was lying trapped in the canyon. By Tuesday, he had run out of water. By Thursday, he realized that he would not survive unless he took unusual action, so he used his pocket knife to cut his arm below the elbow (肘). He then climbed down to the bottom of the canyon. There he met two other hikers, who helped him back to safety. He received some help at a local hospital before being carried to St. Mary’s hospital in Grand Junction, Colorado for surgery.
Ralston’s astonishing survival brought equal amounts of praise and criticism. While praising the climber for his bravery and calm, experts also pointed out he had broken the first rule of outdoor pursuits. He had failed to leave words with anyone of where he was going that day.
This was in fact Ralston’s second near-death experience. In February, he was buried up to the neck in snow by an avalanche (雪崩) while skiing in the Colorado Rockies. Ralston not only managed to dig himself out but he also rescued his skiing companion, who had been completely buried in the snow. Ralton rescued himself and his friend in less than 15 minutes.
1.According to the passage, a “hiker” is probably someone who _______.
A.enjoys walking short distances
B.enjoys walking long distances
C.climbs rocks and mountains
D.likes adventure
2. When a big stone trapped his right arm, ________.
A.he went on climbing the canyon
B.he managed to return to the mountain lodge
C.he cut off part of his arm to survive
D.two other hikers helped him out
3.Why did Ralston’s survival bring criticism?
A.Because this was his second near-death experience.
B.Because he was brave and calm.
C.Because he told no one where he was going when he set off.
D.Because he amputated his arm below the elbow.
4.Which of the following describes what happened to Aron Ralston?
a.A large heavy stone hit him and landed on his arm.
b.He had to cut off part of his arm to get it out
c.He was going through a narrow valley.
d.A search party set out to look for him
e.He climbed down to the bottom of the canyone.
A. c,a,d,b,e B. c,e,a,d,b
C. c,a,b,d,e D. c,e,a,b,d
高三英语阅读理解中等难度题查看答案及解析
--- Sorry for the delay.I got lost in the mountain.
--- OK.You're safe and that's what ________.
A.does | B.works | C.stays | D.counts |
高三英语单项填空困难题查看答案及解析
The hikers made marks on the way ________ they wouldn’t get lost in the mountain.
A.as if B.so that C.even though D.in case
高三英语单项填空简单题查看答案及解析
—Do you know Tom came _____ third in the marathon held yesterday?
—Yeah!And it was _____ 18-hour bicycle marathon.
A. 不填; the B. the; 不填 C. 不填; an D. the; a
高三英语单项填空中等难度题查看答案及解析
-What do you think of the music teacher?
- she is an elegant lady, she can be extremely difficult to work with.
A、While B、When
C、Even if D、As
高三英语单项填空中等难度题查看答案及解析
—What do you think of the new English teacher?
—___she is an elegant lady, she can be extremely difficult to work with.
A.Even if B.When C.While D.Once
高三英语单项填空简单题查看答案及解析
—What do you think of the new English teacher?
—___she is an elegant lady, she can be extremely difficult to work with.
A.Even if B.When C.While D.Once
高三英语单项填空中等难度题查看答案及解析
.—Do you think he’ll succeed?
—Well, he’s helped by so many classmates, what is more, he works extremely hard. So he will________succeed.
A.probably B.likely C.possibly D.perhaps
高三英语单项填空简单题查看答案及解析
In May 2005 he _____the news to his parents that he intended to give up law and become a professional ballet dancer.
A.reminded B.informed C.broke D.got
高三英语单项填空简单题查看答案及解析