A new fitness class has been named the toughest in the world - with doctors and paramedics on hand in case anyone can't handle the intense pace.

London gym chain Gymbox launched its newest class called Flatline at its site in Farringdon, north London.

It is said to be so tough and potentially deadly that participants need to sign a disclaimer beforehand and fill in an organ donor form.

A compulsory oxygen station has been installed as part of the cool-down.

There are paramedics and a professional cardiologist on site in case of emergency medical situations and a compulsory oxygen station has been installed as part of the cool-down.

Curated by experienced Gymbox trainers and leading endurance experts, the class tests all elements of strength and stamina over a 45-minute period – the longest recommended time for a gym class of this intensity.

Participants wear a 12kg weighted vest as they work their way through a grid of activities including kettle bell thrusts, atlas stone throws, weighted rope climbs and box jump burpees. The class concludes with a 45-metre sprint while carrying two ammo cans.

Flatlineis said to be the most dangerous class in the world

The killer routine is then repeated five times.

David Cooper, director of Gymbox, said: “Flatline comes with a significant warning: do not even think about this class if you are unsure in any way about the ability of your body to be pushed to its absolute maximum physical limits, and probably some way beyond. A lot of Gymbox members have said to us that their dream is to have a body to die for. With Flatline that will be a lot closer than some people think.”

The class tests all elements of strength and stamina