A new research has suggested that students who have a much more drastic increase in heartbeat during exams are more likely to achieve better results.
It found that on average the most successful pupils' heartbeat reached a level that was 23.9 times a minute faster than normal, reports the Daily Mail.
And those who performed at the bottom end of the class were found to have a minimal increase in heartbeat - only around 3.9 times their normal rate.
However, there was no evidence to suggest that pupils who said they were nervous had a much quicker heartbeat than normal.
The finding led AQA exam board, which conducted their study at a leading sixth-form college, to suggest that the increase was caused by a heightened alertness rather than a nervous anxiety.
But some anxiety, called 'good stress', seemed to be pivotal to students being able to channel their thoughts and focus on the task in hand.
"This increase in heart rate is a sign that arousal encourages them (the students) to be more alert," one of the leaders of the research, Suzanne Chamberlain, told the Sunday Times.
"It encourages them to work to the best of their ability, it sets the scene for better performance. But we can't say [for sure] it is the direct cause," she said.
The students were fitted with heart monitors in the hours before the exam, and then - of course - during the examination period.
For the highest performers, who achieved an average mark of 78 percent, their heart rate increased from 79.8 beats a minute to 103.7 while sitting the exam.
And the pulses of those who did not fare as well - they scored an average of 53 per cent - their rate only went up slightly, from 78.5 to 82.4.
The study, however, does not recommend that those taking exams use stimulants to boost their heart rate.
The study is due to appear in the Educational Research journal.