Adidas are referring to their 2017 January Sales as a "End of season sale" and they state that customers can save up to 50% on selected products. The official Adidas January Sales is available at the following domain name: adidas.co.uk. End of season sales are probably available at most regional Adidas webstores.
It should be noted that the wording of the sale is "up to", therefore, not every product will have a 50% discount; in fact, most may not. However, just a cursory glance at today's offerings (03/01/17), highlighted a number or products with close to a 50% discount: ZX Flux Primeknit Shoes; Loop Racer Shoes; Gazelle Shoes; Climacool 1 Shoes; Tubular Radial Shoes; ZX Flux ADV Asymmetrical Shoes and X 16.1 Firm Ground Boots. However, critics may suggest that many retailers 'over egg' the recommended retail price (RRP) of the products in their sales and therefore exaggerate the discount on offer.