FEWER repetitions during a high intensity interval training workout may be more beneficial, according to new analysis from the University of Stirling.

Experts from Scotland's university of sporting excellence came to their conclusions after reviewing existing studies which investigate the benefits of regularly performing repetitions of a special type of high intensity cycle sprint, known as the supramaximal.

Findings show that doing fewer repetitions of these sprint intervals on a bike may lead to greater improvements in cardiorespiratory fitness.

Dr Niels Vollaard, health and exercise science lecturer at the university's Faculty of Health Sciences and Sport, explained: “Lack of time is frequently cited as one of the main barriers to people becoming or staying physically active.

“High intensity workouts have begun to tackle this problem, allowing people to get maximum health benefits while working out for a shorter time.

“We found improved cardiorespiratory fitness does not suffer when people complete fewer sprint repetitions and that this may even produce better results.

“The optimal number of repetitions appears to be just two, so workouts based on supramaximal sprints can be kept very short without compromising on the results.”

It has been stressed the findings are only applicable to the supramaximal exercise, which requires specialised equipment.

Whether HIIT workouts at lower intensities also benefit the same way is not yet known, but the research highlighted something important as previously, it had been assumed that performing more repetitions of a high intensity exercise will produce greater improvements in cardiorespiratory fitness.

The analysis was published in the leading journal Medicine and Science in Sports and Exercise with scientists finding that after performing two maximal sprints, each additional sprint in the same session reduced the overall improvement in fitness by around five per cent.

Dr Vollaard added: “For the first time, we have evidence to suggest an indicator of fitness levels is improved more by doing fewer repetitions of high intensity exercise. We are currently performing studies to investigate the physiological mechanisms that may explain this unexpected finding.

“To encourage more people to become active and help increase the health of the population, we need to investigate the optimal duration and number of sprint intervals people could undertake on a bike, while getting the same benefits as longer sessions.”