Electrical muscular stimulation was first used 30 years ago in slimming belts, but advances in technology and a smattering of scientific studies has seen them re-emerge as a training aid for athletes

Remember the 1970s trend for buttock-belts with integrated electrodes that were said to needle the muscles into action by delivering short, sharp electric shocks, thereby removing the need to exercise? For electrical muscular stimulation (EMS) think an updated version with purported benefits for muscles during rehabilitation from injury.

How does it work?

Electrodes on the skin trigger the nerves that operate muscle groups, causing them to contract and relax, just as they would during moderate exercise. By performing strengthening and toning moves when you are wired up to the machine, you intensify the muscular response.

Who uses it?

EMS is widely used in the medical community and prescribed by physios for athletes unable to resume full training after injury. Frank Lampard and Usain Bolt are said to be fans of the Miha BodyTec training system and Germany’s biggest football club, Bayern Munich, is among sporting organisations that have installed EMS units in their gyms.

Any scientific proof?

Studies confirming some benefits, while not overwhelming, do exist. A team led by Professor John Pocari, exercise physiologist at the University of Wisconsin, recruited 72 women who, at the time, did no lower-body training and assigned them to one of three groups. For six weeks, one did nothing different, one was assigned a regimen of lower-body strengthening moves and the third used an EMS buttock toner. At the end of the trial, both activity groups reported improvements in the shape and tone of their posteriors. And tests revealed that gluteal strength increased by 9% among the exercisers and 15% among those subjected to electricity. Muscular endurance (the ability to contract muscles over time) also rose: by 26% among the regular exercisers and 29% among those who had used an EMS device.

Bottom line

There were caveats in the Wisconsin study: the exercisers spent only five minutes working out, whereas the electrical users wore their equipment for 30 minutes daily. And, as the researchers pointed out, there are no cardiovascular benefits to passive EMS exercise. Other small studies have uncovered similar benefits for abdominal EMS equipment, but the evidence is mostly anecdotal. Still, many physios say EMS devices are helpful during recovery from injury.