Amazon has gone ahead with the launch of its private labels for sports products, with three brands at three distinct price points – at least one of them at price levels in the same range as some of the international brands sold by the online retailer.

The three brands include Goodsport for affordable training apparel, which appears to be a derivative of Goodthreads, a brand already established by Amazon in fashion apparel. Goodsport stands for relatively cheap sports apparel, such as women's yoga pants retailing for less than $30 and men's jogger pants just above $20.

Another private label of Amazon is Rebel Canyon for athleisure products, such as men's sweatshirts and shorts, and women's lounge pants. Peak Velocity is a more upmarket brand of men's sports apparel, with fleece hoodies retailing for nearly $80. The brief product descriptions emphasize technical features such as moisture wicking and breathability.

After ads started popping up earlier this year for an Active Apparel team at Amazon, Bloomberg reported in October that the online retail giant started testing production with two Taiwanese companies: Eclat Textile Company, which manufactures garments for Lululemon, Nike and Under Armour; and Makalot Industrial, which has sourced products for Gap, Kohl's and Uniqlo.

The move by Amazon may affect sales of some of the leading international brands on Amazon. Fashion Network reports that Under Armour makes up 25 percent of men's sports apparel sales on Amazon, ahead of Adidas with 22 percent and Nike with just 10 percent, while the suppliers are more diversified for women's products. The positioning of Goodsport, with its cheap leggings and track pants, probably makes it easier to quickly draw customers. Amazon already has several other private labels, for apparel and other categories.

Asked about the move by Amazon on CNBC, Laurent Potdevin, chief executive at Lululemon, said that the private labels were more likely to be commodity products, while Lululemon could cultivate its own positioning through its many stores.

Other analysts feel that the low-priced position of Amazon's private label items will compete more strongly with the recently introduced low-priced activewear offerings of non-specialist retailers!