Exercise may be more than just a way to maintain your waistline and build muscle - it could turn back time.

A study published earlier this year discovered that high-intensity interval training - often abbreviated to HIIT - has an anti-ageing effect on the body.

The workout has become a popular gym workout in recent years, and involves quick, short bursts of exercise.

“It is the best way to burn fat without destroying lean muscle, and your body will continue blitzing through fat for 24 hours afterwards, even if you moved for just 30 minutes,” said Kelly Du Buisson, personal trainer at Healthista.com.

However, the researchers at the Mayo Clinic, in Minnesota in the United States, have also discovered that it can reverse the naturally declining ability of our cells to generate energy.

Age-related decline of cell activity often causes growing fatigue in older people, and reduces the the size and ability of muscles to burn excess blood sugar, placing the elderly at a higher risk of diabetes.

However, after studying two sets of people between the ages of 18 and 30, and 65 and 80, they discovered that HIIT caused this decline to stop or reverse.

While the younger group experienced an increase in the ability cells to generate energy by 49 per cent, in the older group this was an impressive 69 per cent.

“After three months of interval training, everything converged towards what we saw in young people,” said Sreekumaran Nair, researcher at the Mayo Clinic.

They also identified a boost in lung, heart and circulation health.

However, the intense, fast nature of HIIT means newcomers should proceed with caution.

“In order to do a HIIT workout safely you must make sure your form stays correct throughout the workout,” said Joe Spraggan, Head Trainer at F45 Farringdon.

“The workout generally uses high repetitions over time which will fatigue the body and can lead to decreased form quality.”

He said people are at most risk of injuring their shoulders and knees, and urged people to warm up properly beforehand.

Steph Elswood, personal trainer for Fiit - a fitness device launching in March - said if you are previously injured, suffering from arthritis or want to take it easy on your joints for another reason, there are certain switches you can make.

Instead of squat jumps she recommended straight squats, advised replacing jump lunges with step lunges, and also suggested skipping the upwards jump if you’re instructed to do a ‘burpee’.

Crucially, she warned people not to overdo HIIT, despite its many benefits.

“With HIIT you are pushing yourself to the extremes going as hard as you can for a time period before resting. This is why you shouldn’t do it everyday,” she explained.