Few opponents have been able to slow Barcelona. But Nike may have inadvertently managed to do just that -- with shirts that absorb too much sweat. A shirt that weighed 200 grams at the beginning of a match can weigh up to two-and-a-half times as much just 45 minutes later.

The Spanish champions say they have recently met with Nike officials to complain about the new shirts. The team contends the shirts absorb so much moisture they take on added weight over the course of a game.

Dressing room sources told El País that players noticed during a pre-season tour of the US that the shirt "weighed a tonne" and "stuck to the body like a limpet".

Nike is reportedly mulling a takeover bid for Under Armour. This according to the London Times, which reports Nike has been considering an offer for several months. The newspaper said Nike could offer more than $100 per share for Under Armour.

Under Armour's stock shot up more than 7 percent in post-market trading behind the rumours, but later dropped 1.6 percent in Thursday's trading when a Nike spokesman denied the rumours.

Nike is more than 10 times the size of Under Armour, in terms of market cap, but faces stiff competition from the company in the United States. Nike owns the footwear market and Under Armour dominates the athletic apparel market, though both have tried to enter into the other company's primary market.

“After the first ten days it is already clear that this World Cup will be a great success for adidas. We will not only achieve our ambitious goals in football, we will over-achieve them. Our football business is growing worldwide. This underlines the global power this tournament has," commented Herbert Hainer, CEO of adidas AG at the adidas FIFA World Cup™ Media Day in Herzogenaurach.

For adidas, the 2010 FIFA World Cup has already been a success in terms of sales. adidas is now expecting record sales of at least €1.5 billion in the football sector. This represents an increase of more than 15 per cent compared to 2008, the last year of record adidas sales in football (€1.3 billion) and an increase of 25 per cent compared to the year of the last FIFA World Cup in 2006 (€1.2 billion).

In the first quarter of 2010, sales of football products were already up 26 per cent. With more than 6.5 million replica jerseys sold, the number of jerseys has more than doubled compared to 2006 (3 million). This includes bestsellers such as Germany, Mexico, South Africa and Argentina with sales of around 1 million units or more each.

Adidas, Nike and Puma are the best-known football sponsors in the five largest European football markets*.  This is a result from the SPORT+MARKT Report  „European Football Brands Top 20 2009/10“, with the survey of over 3,000 European football fans.

“Jersey sponsors and kit suppliers dominate European communication in football“, says Hartmut Zastrow, SPORT+MARKT Executive Director. To him, Adidas is the major football brand in Europe. However, the expert is most surprised by Audi, in eighth position. “Audi pursues a decentralised football strategy, with partnerships with many European clubs and is even outstripping rival automotive supplier, Ford, as a sponsor.“  However, another reason for Audi reaching the top ten was press coverage of the company‘s purchase of shares in FC Bayern Munich.