I was think­ing of buy­ing a small tram­po­line to improve my gen­eral fit­ness and hope­fully lose 10 — 14 lbs in weight. Are they a good idea? How long should a 65-​year old woman spend on it each day to see res­ults?

I can think of two very good reas­ons why you might want to buy a mini-​trampoline (or “rebounder” as they are often called). They cost a frac­tion of the price of a home tread­mill. And they are a lot more fun.

Mini-​trampolines have been around since the 1970s and high-​street stores sell them at between £30 and £100. The more expens­ive ones fold up and the max­imum weight they take var­ies (the stur­di­est mod­els will sup­port someone up to 140kg or 22^st). Most come with a “how-​to” book and/​or DVD.

If you read the mar­ket­ing blurb you’d think they were miracle-​machines, with claims that they can reduce your blood pres­sure, help ban­ish cel­lulite, de-​fur your arter­ies, increase your bone dens­ity, ener­gise and detox­ify you and reduce your arth­ritic pain.

Unfortunately there seems to be very little inde­pend­ent sci­entific evid­ence to sup­port any of these claims. This doesn’t mean mini-​trampolines are use­less – many gyms, physio­ther­ap­ists and ath­letes use them. Just don’t rush out and buy one because you believe it will sort out your cel­lulite.

The reg­u­lar, rhythmic gentle boun­cing action is a very good form of car­di­ovas­cu­lar exer­cise: it gets your heart rate up and your breath­ing going. If you main­tain a decent effort level (akin to a brisk uphill walk) for the right length of time (up to 30 minutes), three to five times a week, you should feel some health and fit­ness bene­fits.

As with any exer­cise, start cau­tiously (per­haps just a few minutes) and build up the time and intens­ity of your workout over the weeks. For the first few ses­sions it’ll feel odd, both because it’s an unstable sur­face and because grav­ity is play­ing around with your body as you bounce. Do read the man­u­fac­tur­ers’ advice about tech­nique: it’s not at all like a big tram­po­line and I wouldn’t advise jump­ing on it with both feet: more of a gentle “cyc­ling” or step­ping action.

If you use it dili­gently the main health gains will be in your heart and lung fit­ness, plus some muscle ton­ing. Another pos­sible added bene­fit is improved bal­ance – the wob­bli­ness of the rebounder chal­lenges the body’s joints to sharpen up their reac­tions. But if it’s too unsteady for you at first, you can buy a sta­bil­ity hand rail with some mod­els, to give extra bal­ance sup­port. Use this at first, but aim to rely on it less and less as your bal­ance and strength improve.

You’ll only lose weight if you also con­trol your food intake and increase your over­all activ­ity levels.

Despite the lack of research back-​up, I also like the fact that mini-​trampolines are “low impact”: the springs cush­ion your skel­eton far more than is pos­sible when you jog on dry land, which may make it a use­ful tool for some people with arth­ritis.