Researchers have told the government to look again at AS levels because pupils are overwhelmed by work.
The message comes after a two-year nationwide survey of AS levels by a research team led by Jacky Lumby of Leicester University.
Every sixth-form college in the country received a questionnaire aimed at staff and students. Selected further education and secondary schools were surveyed.
The key finding was that students and staff are suffering curriculum overload, which, according to the respondents, the government must acknowledge and act upon.
Professor Lumby said: "Students were very, very angry, and their message to the government is to stop doing too much, too quickly. Staff were very worried that some of the enrichment activities that they saw as crucial - such as sport, art and community activities - were being squeezed out.
"There was also a strong feeling that the amount of work that students have to go through to prepare for exams meant that there was little time for thinking and learning."
AS levels - which have proved to be an administrative nightmare - are part of Curriculum 2000, which was introduced to broaden the sixth-form curriculum to give young people more options for further and higher education study.
Universities are being urged to adapt their entry requirements to include AS levels. But some institutions accord little weight to the new qualifications, preferring instead to make offers based on only A levels.