（去）做瑜伽 or 练瑜伽 我明天要去做瑜伽。 I'll go to do yoga tomorrow.

http://www.italki.com/answers/question/154013.htm

IT MEANS 去做瑜伽。no Chinese would say 去练习瑜伽 because it is too formal.and 去上瑜伽课 means to take some yoga lessons ,i think it may not mean what you wanna say.

means“去练习瑜伽”或者“去上瑜伽课”。This is good both phsyically and mentally.I have classses every weekends.