A studio, run by eleven teachers from north west Wales, has opened for one week in a shop in the high street that would otherwise be empty.
They hope it will help them grow their businesses and attract more people to the city centre.
It is part of a Gwynedd council scheme to bring empty shops back into use.
"The great thing about yoga is that it brings balance," Porthmadog yoga teacher teacher Claire Mace told BBC Radio Wales' Jason Mohammad programme.
"If your Christmas shopping is making you feel sluggish and tired, it might help you feel more energised. If you're really stressed and hyper at this time of year, it can calm you down.
"In December, we're all running round getting very excited about Christmas, buying presents and food, but maybe this will also give people ideas about things they could do as a new year's resolution as well."
Josie Ryan from Menai Bridge, who joined the class, said: "I feel really relaxed after that - not stressed at all. This may be the most Zen Christmas shopping I've ever done."
Ffion Rowlinson, from Bethesda, added: "It was marvellous, really relaxing. It was funny doing yoga on the floor while stressed people walked past the window with their umbrellas doing their Christmas shopping."
Shoppers in Bangor are being offered free yoga classes to help reduce their stress levels while Christmas shopping.