Every November, an army of impossibly-honed and impeccably groomed women strut down a runway in their underwear.

Love it or hate it, the Victoria’s Secret show is an entertainment force to be reckoned with, and each year strikes up the same question: what kind of magical fairy dust have these women been drinking to look like that?

According to celebrity trainer Michael Blauner, it’s down to something called LISS.

Not to be mistaken for lying in spas and saunas all day, though we suspect that would do us the world of good, LISS stands for low intensity sustained state.

Essentially, this means engaging in slower and longer workouts at a less fervent level.

LISS could include a 30 minute jog, a 40 minute cycle or an hour-long swim.

It’s a form of exercise that’s favoured by the likes of Adriana Lima and Miranda Kerr - and according to Blauner, it’s the best kind of cardio for achieving and sustaining weight loss, he told POPSUGAR.

Whilst other trainers will glorify the benefits of HIIT (high intensity interval training), which can be tough on the joints, Blauner swears by the slower and less intense concept of LISS.

Though the latter will consist of a longer workout than its quick-blitz counterpart, it will ultimately give better results in the long term, he claims.

“You tap into stored fat more when the body uses oxygen as an energy source," he explained.