Jump to it: Kangoo Jumps are great for joints Jas Lehal

A throng of fundraisers will bounce through the streets of Covent Garden in a fortnight on the type of sprung shoes used by Nasa astronauts. With places still available for the 4km charity race, you can join the 200 Kangoo jumpers taking part on 2 September.

For those of you uninitiated in the lolloping craze, it’s a workout wearing what looks like a pair of ski boots glued on top of a six-inch egg-shaped spring.

I think they are mildly ­terrifying and can’t imagine why anyone would want to risk living the rest of their life in a neck brace to jump higher than a bus shelter. But race ­organisers say ­Kangoo workouts are one of the most popular on the gym circuit .

Designed by Canadian physiotherapists, the boots were invented to re-introduce patients to exercise following injuries or surgery. Nasa quickly noticed the invention and gave the boots to astronauts who had returned from space. After months of experiencing zero gravity in space, the joints of astronauts were not prepared for traditional aerobic exercises such as jogging or skipping, but the Kangoo springs offered the benefit of absorbing heavy impacts.

According to Nasa ­research, considerably less strain is placed on joints like ankles, knees and hips when using the Kangoo Jumps than is placed on joints when wearing trainers.

But how does it shape up as a fitness craze?

Race organiser Jon Ramage, of Gymbox, says that 20 ­minutes of Kangoo burns as many calories as 40 minutes of more traditional sports (about 400 calories), as your leg muscles have to work hard to maintain balance.

He says: “You’ll have tighter glutes, firmer thighs and calves of steal, plus your abs and core muscles are working out to keep you upright.”

With that in mind, I jump at the chance of a spring-loaded workout.

After struggling into my boots, I gingerly head out of Gymbox, Covent Garden.

“Keep your head up!” shouts instructor Jason ­Mellars, as he pushes me out the door.

Apparently, the head is the heaviest part of the body, so looking down means you’ll probably end up on your rear end. As the boots make me 6ft 3in, I do what Jason says as I have a long way to fall.

I stumble, stagger and eventually skip down St Martins Lane towards St James’s Park for our ­outdoor workout.

“The trick is to think of it as bouncing through the ground not on the ground,” Jason explains.

“Use all of your bodyweight to push downwards and this will leave you more balanced and give you a better workout.”

I cast my inhibitions to one side and spring up and down on the spot like I am stamping on the head of someone I hate. It works and it’s a great stress-buster – much ­better than plodding on a treadmill.

We then work through a series of moves that I’ve done ­before in regular exercise – squats, grapevine, star jumps and tuck jumps. I feel a bit scared but I take a deep breath and ­believe I can do it.

The secret is to go with the flow. The only time I almost fell over was when a Japanese tourist tried to take a photo of us and I suddenly realised that boinging around on a six-inch spring was an ­unusual thing to do.

After the class, I was pleased to give the boots back and waddle into a shower (­Kangoo’s a sweaty business). I don’t normally work this hard when I use gym treadmills and my thighs definitely feel tighter.

Kangoo boots cost £149 a pair, which is good value considering my last pair of trainers cost me £100 and the Kangoo Jumps worked me twice as hard.

However, I think I am too vain to do it regularly. I’ll do the run because it’s for charity but I may wear sunglasses to avoid being recognised.

To enter the charity run email Jon Ramage on jonr@gymbox.co.uk. For classes see gymbox.co.uk