Morning best for learning maths but history lessons better after lunch - study
Schools could see their maths scores rise if they timetable lessons in the morning, research suggests.
But youngsters do better in history if they have classes after lunch.
The study, by an academic at Royal Holloway, University of London, looked at academic achievement, class schedules and absence rates at a Bulgarian school over nine years.
The findings, due to be presented at the Royal Economics Society annual conference, show that when teenagers had maths classes earlier in the day, they did better than if they had the same class in the afternoon.
For history, the opposite was true.
Overall, pupils scored around 7% higher when they had a maths class in the morning compared with the afternoon, while history scores were about 6% higher after lunch.
There was no pattern for any other subject.
"The findings indicate that afternoon classes lowered maths test scores and increased history test scores, which relate to psychology and neuroscience research about optimal functioning in different times of the day," the study concluded.
It indicates that by rearranging timetables, schools could improve students' results, said author Velichka Dimitrova.
The findings back up psychology research which has found it is better to perform repetitive, automatised tasks earlier in the day, while work that involves making sense of something is better later on.
Ms Dimitrova said: "Rearranging school schedules in a more optimal way does not require investment of additional resources and could be a cost-effective intervention leading to improvements in academic performance."