A pioneering headteacher is calling for all secondary schools to follow his lead and start classes at 11am, allowing teenagers two hours extra in bed.

Dr Paul Kelley, head of Monkseaton Community High School in North Tyneside, said it would mean the end of "teenage zombies" dozing off in lessons before lunch, after experiments showed teenagers could have different body clocks from adults and younger children.

Russell Foster, an Oxford professor of neuroscience, tested the memory of 200 Monkseaton pupils at 9am and 2pm using pairs of words, and discovered a 9% improvement in the afternoon. Students correctly identified 51% of word pairs in the later session, compared with 42% in the morning. Tayler McCullough, 15, one of the test subjects, said the majority of students would welcome the extra hours in bed. "I'm extremely hard to get up in the morning. One or two people like to get to school early, but most of us would be up for going in later. I'm sure it would make a big difference to our learning ability."

Kelley is adamant a change of school timetable will have a significant impact on exam performance. He said: "Teenagers aren't lazy. We're depriving them of the sleep they need through purely biological factors beyond their control. This has a negative impact on their learning, and possibly on their mental and physical health. We've just learnt of this, but it is vital that we act on it.

"The research carried out by Professor Foster showed that, from the age of 10, our internal body clocks shift, so it's good for young people to stay in bed. They peak at 20 then gradually go back again, but body clocks do not reach the pre-teenage level until around 55 years old. The 'time shift' is two hours on average, so teenagers should get up two hours later. We are making teenagers ratty by making them get up early."

He wants his school's governors to approve his plan and put the new timetable in place before the opening of Monkseaton's new £20m school building, the most technologically advanced in the country, in September.

Kelley has a history of groundbreaking teaching methods. In January, he carried out a trial at Monkseaton High that found pupils scored up to 90% in a GCSE science paper after one session involving three 20-minute bursts interspersed with 10-minute breaks for physical activity. The 48 year-nine pupils had not covered any part of the GCSE science syllabus before the lessons. In 1998, Kelley established a scheme with the Open University bridging the divide between school and university by allowing sixth formers to study undergraduate modules alongside their A-levels.

Kelley hopes his latest idea will be just as successful. "We have to be pragmatic. But this proves that, by starting later, children's learning improves, as does their health."

Foster said: "This is preliminary data, but what's exciting is that it matches more detailed studies carried out in Canada and the US. Teenagers get up late not because they are lazy but because they are biologically programmed to do so."