An advert for a long-sleeve T-shirt which claimed to "improve strength and endurance” has been banned for being misleading.
Sportswear company Under Armour said its Men’s UA RUSH Compression shirt's abilities were “tested and proven" in a promotional message on its website on February 15, 2020.
It claimed the garment's mineral-infused fabric “absorbs the energy your body emits and reflects it back into your tissues and muscles”.
However, a ruling published on Wednesday by the Advertising Standards Authority (ASA) said the ad was “misleading” as the evidence given to support the claim that the top had been “tested and proven to improve strength and endurance” was “not adequate”.
The ad suggested that during exercise the shirt noticeably improved strength and endurance for the wearer, over the area of the upper body that it covered, the ASA said.
Two studies provided by Under Armour to prove its claims had used a shirt which was different to the advertised product.
The company said the product enhanced performance due to a material called Celliant, a blend of thermoreactive minerals which could be embedded into fabrics.
The brand said that products with Celliant improved performance, and specifically strength and endurance, by recycling an athlete’s own energy.
One small study of 12 male cyclists suggested average oxygen consumption was lower when participants were wearing Celliant-containing clothing and excercising at a low intensity
The regulator said it was “unclear” whether the clothing would improve a wearer’s endurance at race pace.
The ASA has told the sportswear company the ad must not appear again in its current form.
“We told Under Armour UK Ltd not to state or imply that the advertised product would improve strength and endurance unless they held adequate new evidence to support the claim,” the ruling said.
