Should you do a runner from toning shoes Figure-fixing trainers promise leaner legs. We asked a scientist to put them to the test…
16:23 GMT, 19 March 2012
Toning shoes, we are told, will result in leaner legs, thighs and buttocks — and calories melting away. And it seems the promise of slimmer pins with a minimum of effort is one that women have taken to heart.
Toning shoe sales in the U.S. increased from $17 million in 2008 to nearly $1 billion last year. Women make up 85 per cent of the market for the shoes with rocking soles, in-built wobble boards or special pods designed to provide a ‘mini workout’ with each step.
Most brands of toning shoe have a degree of instability in the sole that, in theory, encourages muscles, particularly those in the legs and buttocks, to work harder just to maintain balance.
Enviable figure: Kelly Brook wears Reebok Easytone shoes but can they really give you toned legs like hers
Some makers claim that one step in a toning shoe is the equivalent to three in a normal shoe.
But doubt was cast about the real benefits when Reebok was fined $25 million by the U.S. Federal Trade Commission for making false claims about its EasyTone line of footwear.
A review of toning footwear was also conducted at the University of Wisconsin for the American Council on Exercise, an independent watchdog, and published in their journal.
One researcher, Professor John Pocari, said: ‘Don’t buy these shoes if you think they’re going to burn more calories. That’s wrong.’
Many manufacturers say they have research to back up the claims about their footwear, but experts question how rigorous the tests were in terms of scientific standing.
‘Unless a study is published in a peer-reviewed journal, it has not been externally evaluated and is not considered to provide any firm evidence,’ says Iain Fletcher, a researcher in biomechanics at the University of Bedfordshire’s department of sport and exercise science.
So how effective, if at all, are toning shoes, which have attracted celebrity fans such as Kelly Brook and Heidi Klum
Fletcher and his team studied the most popular products in their high-tech sports science laboratory.
Using a non-motorised treadmill to simulate normal walking and wiring subjects up to electromyography (EMG) equipment, the scientists were able to test whether the toning shoes prompted greater muscle activation in the calf, quadriceps (front of the thigh), hamstrings (back of the thigh) and buttocks compared with the subjects’ own standard running shoes.
Then they assessed the vertical and horizontal forces incurred when walking in the different shoes to see whether the body needed to work harder.
They also measured the oxygen consumption of participants, an indicator of burning extra calories. Each test was designed to examine the particular claims of each maker; Fletcher and his team then gave their verdicts and we asked the manufacturers to comment:
Mixed response: Fitflops had the highest score in buttock muscle activation but many testers found them difficult to walk in
PRICE: From 36 to 175.
CLAIMS: More than 12 million pairs of the world’s first ‘muscle-activating flipflop’ with in-built ‘micro-wobbleboard technology’ have been sold.
The soles feature a low-density midsection said to ‘increase lower leg muscle activation by up to 11 per cent’.
The makers quote studies that say FitFlops improve ‘bottom muscle activation by up to 30 per cent’ and ‘hamstring muscle activation by up to 16 per cent’.
MUSCLE-TONING RESULTS: The FitFlops fared considerably worse than the control group when it came to muscles used when walking.
The shoes produced 50 per cent less activation in the quadriceps than in the subjects’ usual trainers — the lowest score of all shoes tested.
Both hamstring and calf muscle activation was greater in normal trainers than in FitFlops.
However, of all the toning footwear tested, FitFlops did achieve the highest score in buttock muscle activation.
EXPERT COMMENT: People found this flipflop-style difficult to walk in at the test speed (4.4 km per hour), as they had to claw with their toes to keep them on and couldn’t push backwards with each stride.
Whatever footwear you are wearing, the faster you walk, the more calories you burn, so this was a clear disadvantage.
The FitFlop had the lowest score for horizontal force.
However, it had the second highest buttock muscle activation of all the footwear tested, including normal trainers.
VERDICT: FitFlops activated buttock muscles more than trainers and all but one (Skechers) of the other toning shoes, but were least effective of all shoes at working the muscles at the front and back of the thighs — but, then, these are flipflops.
We expect FitFlop trainers would fare better. Only Skechers performed worse at activating the calf muscles.
THE RESPONSE: FitFlop declined to comment.
Don't expect a transformation: Reebok's Easytone does work some muscles but not enough for noticeable results
CLAIMS: Shoes featuring ‘pods with Moving Air Technology transfer air in response to your stride and create micro-instability with every step’.
Following an investigation by the U.S. Federal Trading Commission, advertisements stating that the curved sole design of the shoes would give wearers 28 per cent more strength in the buttock muscles and 11 per cent in the calf muscles compared with ordinary trainers have been withdrawn.
MUSCLE-TONING RESULTS: Activation of calf and quadriceps muscles was better than normal trainers, although they were not the best performing of the toning shoes.
And although the EasyTone shoes achieved the best scores of all the toning shoes for hamstring activation, they did not perform as well as ordinary trainers.
With bottom toning, they scored higher than ordinary trainers and the MBTs, but worse than the rest.
EXPERT COMMENT: The EasyTone shoes performed relatively well in some of the muscle tests, but had only average scores for forces applied during walking (effort) and for calories burned.
Like most of the other toning footwear, these shoes create some instability, but that does not translate to better toning of the legs and bottom. On an unstable sole, the body makes adjustments that means it uses tiny balancing muscles to stay upright.
It’s these that work harder, not the big muscles people are hoping to tone. The physical, and visible, effects are negligible.
VERDICT: Better than ordinary trainers when it came to working the buttock and calf muscles, and those in the back of the thigh, but not as good as most of the other toning shoes. Worse than trainers at working the muscles in the front of the thigh.
THE RESPONSE: Reebok was unable to comment on our tests, but said the results of its own 12-week study of 82 participants (which it considers to be more robust than EMG testing) were that, while no weight loss occurred, the women wearing EasyTone shoes reduced their body fat and benefited from a corresponding increase in lean body mass.
Top in buttock toning tests: Skechers tone ups
SKECHERS TONE UPS
CLAIMS: ‘Designed to help tone thighs and calves, firm buttocks and burn more calories’, these shoes feature ‘kinetic toning pods’ in the midsole that create ‘natural instability’ to work muscles harder.
The manufacturers claim that four clinical studies in the U.S. and Japan show Skechers shoes ‘increase muscle activation and calorie consumption over standard fitness shoes’.
MUSCLE-TONING RESULTS: Skechers shoes produced the greatest activation of quadriceps muscles of all the toning footwear, but still significantly less than regular trainers.
They achieved the highest score for buttock muscle activation and were the second best of the toning shoes at working the hamstrings, although not as good as normal trainers.
However, they performed worst of all shoes when it came to activating the calf muscles.
EXPERT COMMENT: Skechers did well on tests of buttock muscle-activation and produced the highest score for horizontal force — a measure of effort.
That was better than the other toning footwear and standard trainers.
However, they had the lowest oxygen consumption scores of all the shoes tested, which translates to calorie-burning.
VERDICT: Came top of all shoes (including trainers) in buttock toning tests and measures for effort, but had the lowest score for calorie-burning and trainers were better at thigh-toning.
THE RESPONSE: Skechers did not respond to our request for comment.
Best at calf toning: MBT
CLAIMS: The distinctive curved sole of the MBT shoes are said to ‘induce instability that your body instinctively attempts to correct’.
Just standing or walking in them ‘can help add more movement into everyday life and can also lead to increased muscle activation and can help improve posture and balance’, say the manufacturers.
MUSCLE-TONING RESULTS: Performed better than normal trainers at buttock-toning, but were not as good as any of the other toning shoes in this test.
Better than all shoes (including trainers) at activating calf muscles, but worse than normal trainers at working the thigh muscles.
EXPERT COMMENT: Many of the studies performed on MBTs are for pain relief and postural improvements, factors that weren’t being looked at here.
In these tests, they performed averagely in muscular-effort assessments and in calorie burning.
Anecdotally, people say they notice a difference after switching to shoes like these and that their legs feel tired, which they take as a sign that the shoes are working.
However, that is not necessarily the case and the reality is the body is adjusting to doing something new.
The tiredness is likely to subside with regular use and will not automatically lead to a more toned appearance.
VERDICT: MBTs were the best at calf-toning, but performed worse than ordinary trainers at working the thighs and had the lowest score of all shoes, apart from trainers, at activating buttock muscles.
THE RESPONSE: ‘MBT was created to mimic walking barefoot, which we agree with your expert is a much healthier way to walk.
‘The reality is, in modern life, we cannot always walk barefoot. MBT, we feel, is the best alternative is this environment, and we do not promote our products as toning.
'Rather we focus on our medical benefits, and as such we are viewed as a class 1 medical product in the European Union.’