Dame Helen Mirren’s 12 minute exercise plan

Twelve minutes. It’s not a long time, is it Long enough to boil bronze-extruded spaghetti, send a few emails – or ensure that, like the Mounties, you will always get your man.

A now-obsolete Canadian military fitness plan, which takes just 12 minutes daily, has been credited by Dame Helen Mirren as the elixir of her youth and the reason why she can still rock a coral bikini in her sixties.

The Royal Canadian Air Force (RCAF) programme, developed in the late Fifties and published in booklet form, was once an international best seller. Around 23 million copies in 13 translations were sold across the globe and the simple (yet effective) exercises were hugely popular in Britain.

The Royal Canadian Air Force (RCAF) fitness program.

The regime, tailored to improve fitness in RAF pilots posted to remote air bases without gym facilities, is called 5BX for men and XBX for women. The men’s routine consists of five simple activities: stretching, sit-ups, back extensions, push-ups and running on the spot. The women’s version has 10 exercises, and includes side leg raising and arm circling.

As fitness increases, so too does the difficulty of every exercise; but, crucially, the length of time stays the same. If this is starting to sound rather familiar, you’re not wrong; RCAF was the original high-intensity work-out, which was largely forgotten, then reinvented, repackaged as “Interval Training” and sold as a brand new innovation.

Older generations swore by it; the actor and comedian George Burns, who died in 1996 at the age of 100, was a fan. The regime fell out of vogue and was confined to die-hard adherents, but it doesn’t take Nostradamus to predict a fresh flurry of interest once the Mirren-effect kicks in.

Unlike the soign