More than 20 high school students in Hubei province had intravenous infusions of amino acids in their classroom in the hopes of providing extra energy to prepare for the national college entrance examination scheduled for early June.

The infusions, which doctors said were neither necessary nor wise, raise concerns about the health of students and the fierce competition in education.

Several pictures were uploaded to the Internet showing dozens of infusion bags hanging over the heads of a group of students in a classroom at Hubei Xiaogan No 1 High School on Friday night.

The lights were on in the classroom and books were piled up high on the students' desks. Some students were receiving infusions while doing their homework.

"The fluid in the infusion bags was amino acids to power up the students. They took such an infusion of their own accord," said an official surnamed Xia from the school, Changjiang Times reported on Sunday.

The official also said that it was getting hot, so many students felt uncomfortable, asking for the infusion. But the school clinic did not have enough room for them, making them take the infusion in their classroom.

But many doctors said the infusions can do nothing positive and could be harmful.

"Infusion of amino acids is not necessary at all for students in good health," said Gao Huiying, chief physician with the Chinese Nutrition Society.

"Amino acids serve as the building blocks of proteins, while excessive intake of protein will increase the burden on the kidneys and cause a loss of calcium."

Furthermore, intravenous infusion may cause an adverse reaction of the body, such as trembling and sweating.

"What they need is to keep a balanced diet. If they need more energy, they can have extra meals," she said.

Chen Ting, a doctor with the People's Liberation Army 455 Hospital in Shanghai, echoed Gao.

"Having intravenous infusion in the classroom violates the principle of keeping the environment germ-free. Such an infusion at all is unwise," Chen said.

The pictures of the students receiving the infusions became a hot topic online.

Many netizens commented that they understood the students' burning desire to make their bodies perfect during exam preparation because their performance at the college entrance examination may decide the rest of their lives.

But many others called them crazy and blamed the examination for their behavior.

For example, a netizen from Beijing with the name "Mozhisiyu" commented on her micro blog that the country's education system makes them use such extreme ways to prepare for the examination.

"I don't think it's inappropriate at all," one of the students in that classroom, a 17-year-old student who would only go by the surname Chi, told China Daily.

"Students preparing for the college entrance examination at our school began to take infusions of amino acids years ago and some of them took them more than twice."

"Some people's misunderstanding and criticism makes us unhappy and disturbs our preparation. The examination is coming in a month and it's urgent we need to keep our minds at ease. Please give us more tolerance."

"It (infusion) may not have an immediate effect to make us more energetic during the tense preparation, but at least it brings us some kind of psychological comfort that we have more power to move on," she said, while admitting she felt nothing improved after the infusion, and she still felt exhausted.

Teachers in the school also supported the students taking an infusion of amino acids. Chi said it was the teachers who fixed iron wires in the classroom to hang the infusion bags. And many parents also asked the school to give extra amino acids for their exhausted children.

Chi said her teacher told them that the school had received some subsidies from the central government that made such infusions much cheaper, and they only had to pay 10 yuan ($1.60) per bag if they took it from the school clinic, while it may cost at least 50 yuan outside.

The school declined to make any comment when interviewed by China Daily.

zhengjinran@chinadaily.com.cn