Barely a week goes by without another fitness aid claiming to transform your workout with its cutting-edge technology — trainers to ease back pain, workout pants to speed weight loss and bracelets to boost energy. Which work, if any? We review the evidence.

Weight-loss hot-pants (zaggora.com)
Product More than 600,000 pairs of Zaggora leggings have been sold since they were launched two years ago. The reason? They are said to aid weight loss and fat burning with ThermoFit technology.
Promise Zaggora claims: “Our patent-pending fabrics are scientifically proven to increase calorie burn [and help] smooth the skin and reduce cellulite.” The ThermoFit fabric is said to work by “harnessing the body’s natural heat to help you burn more calories” as you move. Zaggora HotPants are said to target your knees, thighs and bottom, even if all you do is walk around the house.
Evidence A small study at the University of Brighton, commissioned by Zaggora, compared the company’s HotPants with ordinary workout gear worn during 30 minutes of exercise. It found that they not only increased body temperature but boosted energy expenditure (or calorie burning) by 11.3 per cent during the workout and by 12.5 per cent when worn during recovery. Another test at the University of Southern California found Zaggora-wearing exercisers burned 9.7 per cent more calories during a half hour workout than those wearing ordinary clothes. Some scientists think the claims are too good to be true. Professor John Porcari, a sport scientist at the University of Wisconsin, recently tested a similar range of toning pants on female volunteers and found they had a negligible effect on calorie-burning — “the equivalent of half a single peanut M & M”. Prof Porcari did say, however, that “they may offer some psychological benefits” by helping you feel and look better as you work out.
Verdict Calorie burning is minimal. They’ll do little more than keep you warm.

CrossFit Shoes (reebok.co.uk)
Product Reebok’s latest innovation is a trainer that moulds to your foot — with the aid of a hairdryer. Containing U-Form+ material, the shoes offer a customised fit that is said to help prevent injury.
Promise No more blisters and injury caused by ill-fitting shoes. Reebok says the U-Form+ technology keeps the foot aligned “and also helps to lock down the heel, a crucial element in performing at your best”. The material is located inside the shoe. It starts mid-foot and wraps around the heel. It reacts to the heat of a hairdryer held 10cm away for two minutes. The shoes are then laced tightly for a snug fit.
Evidence Shoes that are either too small or too large can cause injuries. Katharine Dux, a podiatrist at Loyola University Medical Centre, Chicago, is looking at the problem insofar as marathon runners are concerned She says that every year between 200 and 400 runners in the Chicago Marathon seek treatment for blisters, toenail injuries, plantar fasciitis (heel pain), foot stress fractures and sprained ankles. Many of the injuries are due to shoe problems. There is no scientific evidence, however, that Reebok’s U-Form+ shoes offer a better fit. Dr Laura Charalambous, a researcher in sports biomechanics at the University of Bedfordshire, says:“I can’t envisage any performance advantages to this Reebok shoe. I’m also concerned [it] may restrict the natural changes in size and shape of the foot during stance.”
Verdict Might be comfortable but unlikely to reduce injury

Recover Plaster (fireflyrecovery.com)
Product Recovery from workouts is often overlooked by gym-goers and yet top athletes know it is of prime importance. The secret weapon for many is the Firefly, a sticking plaster the size of a wristwatch worn behind the knee to deliver electrical impulses that are said to reduce muscle soreness.
Promise According to the maker, the daily-disposable device “reduces delayed onset muscle soreness within 24 hours” and accelerates “leg muscle recovery” making it the perfect choice for runners, cyclists, footballers and swimmers. It works, they say, by stimulating blood flow — known to help recovery — but without you having to move or exert energy.
Evidence Unlike many fitness gadgets, this has plenty of scientists confirming its credibility. It was used in the 2012 Olympics by medal-winning Team GB athletes and has been tested and endorsed by UK Sport. A study at Loughborough University showed that the device reduced soreness after exercise better than compression clothing. Dr Scott Drawer, head of research and innovation at UK Sport, says the Firefly’s “physiological effects, portability and ease” makes it a great tool for very active people.
Verdict Yes. Perfect for those training for a marathon or triathlon.

Energy Bracelets (powerbalanceuk.com)
Product Power Balance bracelets have been seen on the wrists of everyone from the Duchess of Cambridge to Robert DeNiro and David Beckham. The thinking is that holograms set in the silicone or neoprene bands, enhances the body’s natural energy and, some believe, can boost fitness or performance.
PromiseThe maker’s website has a long list of athletes who wear its products, and says the new Power Balance Pro Ion technology “includes natural ions so you can bring a little bit of nature’s essence into your everyday life”. It adds, however: “There is no assurance it can work for everyone. That’s why the product is sold with a no-quibble 30-day money-back guarantee”.
Evidence Power Balance is cagey about making claims for its products after it admitted to the Australian Competition and Consumer Commission that it had no scientific evidence. A peer-reviewed study commissioned by the American Council on Exercise (ACE), revealed two years ago that the bracelet did not improve flexibility, balance, strength or power in a series of double-blind tests. Cedric Bryant, the council’s chief scientific officer, says: “We ultimately found that the bands had no impact on performance outcomes.”
Verdict Any boost is likely to be psychological.

Anti-bounce bra (lessbounce.com)
Product Finding a bra that prevents workout jiggling is a holy grail. The search could be over, says the maker of the Lynx bra, which claims it is the first to provide breasts up to size 52K with upwards, downwards and sideways support during exercise.
Promise The bra’s designer, Cynthia Smith, a “large breasted” molecular scientist and marathon runner, says she struggled for ten years to find a sport bra that offered comfort and a flattering look. She says: “[I had] a eureka moment, sourcing fabric from downtown Manhattan and creating something that worked better than anything I’d ever worn.” The result, she promises, is a bra that offers “outstanding support and motion control to women of all sizes”.
Evidence Experiments by the University of Portsmouth’s breast health research group headed by Dr Joanna Scurr charted the trajectory of breasts using infrared cameras. It found that breasts move through a figure-of-eight pattern when a woman runs or walks. When not constrained, each breast swung as much as 21cm during a treadmill run. What’s said to be unique about the Lynx bra is that it gives support from the sides instead of just the shoulder straps and band. In studies at Loughborough University involving women with cup sizes DD to G cup, the Lynx bra’s bounce factor outperformed rival products, providing more comfort.
Verdict worth a try for the busty.

Fitness trackers
Product Fitness and activity trackers are said to be smart-coaching products that measure movement and energy expenditure. The most popular include the Nike+ Fuelband, Fitbit, Fitbug, Jawbone Up and Garmin Vivofit . This week sees the launch of the Polar Loop, a bracelet that tracks activity and prompts the user on how to reach daily goals.
Promise Trackers are worn in various ways: on the hip, arm or wrist, or as a neckband , but the concept is the same. They sense movement and that data is used to determine calories being burned.
Evidence A UK survey last year — sponsored by Fitbit — says 50 per cent of tracker users report “strong behaviour change”. Studies on people using pedometers suggest that they become more active when they think activity is being tracked. The accuracy of the devices is questionable, however. Nate Meckes, an assistant professor at Azusa Pacific University, California, told the American College of Sports Medicine last summer about his experiment on tracker reliability. Meckes fitted 16 volunteers with three different trackers as well as masks to measure oxygen consumption to help calculate energy output. Each subject then took part in activities including treadmill walking or jogging, cleaning, standing up, sitting at a desk and playing a board game.
Verdict The trackers accurately measured energy output when walking but were off the mark with the less strenuous activities. Meckes’s findings last summer were backed by a study published in November in Medicine and Science in Sport and Exercise. Ray Browning, professor of exercise science at Colorado State University, found that hip-mounted accelerometers underestimated the energy involved in standing up, cycling and walking or jogging uphill. Scientists say the device accuracy is likely to improve. At present they are better at monitoring walking and running, not so accurate for cycling and unreliable for standing and housework.

Compression wear (store.skins.net.uk; 2XUshop.co.uk)
Product A favourite of top runners, tennis and rugby players and footballers, this tight-fitting clothing — from “Paula Radcliffe” knee-high socks and leggings to tops for men and women — is made with a lot of Lycra (or other elasticated material) that squeezes the muscles used in exercise and, much like anti-DVDT compressions stockings, is said to improve blood flow around the body.
Promise Compression kit promises to help you workout more efficiently, avoid common injuries and recover faster in any sport or workout that involves vigorous effort. The theory is that by squeezing blood vessels, compression clothing causes them to open forcefully. The upshot is more blood and oxygen delivered to the compressed muscle and more waste products forced outwards. There are suggestions that the clothing also improves sports performance and lessens the risk of injury.
Evidence Companies like 2XU have worked in “association with leading sports institutes and research bodies, such as the Australian Institute of Sport” to produce their compression garments. Certainly, some researchers have found the tight-fitting garments are helpful and their evidence suggests they do enhance blood flow in the area being compressed. In research at the University of Wuppertal in Germany earlier this year, sport scientists reviewed all of the latest studies on compression clothing and found they had little effect on improving sprint time, jumping height or endurance performance but that there was some benefit when it came to their ability to reduce muscle pain and swelling after exercise. But verdicts are mixed. Two studies at Indiana University a couple of years ago looked at the effects of compression socks and tights on runners. Neither found them to be helpful in conserving energy when running or on improving running style to lessen the risk of injry. Others have shown they don’t improve 10K running speed. However, the clothing havs been shown to significantly reduce delayed onset muscle soreness (or DOMS) that occurs after hard exercise so might aid recovery, leaving you fresher for the next day’s exercise.
Verdict Helpful for recovery, but unlikely to boost performance and there’s no proof it helps to prevent injury.