There are two long phrases in this paragraph
1 Le yoga………les “pranayamas “ en Sanskrit, qui apprennent …………, ce qui à son tour ……………
2 En outre, le yoga offre de nombreux styles…………qui varient………….., ce qui le rend………………In both there is no doubt as what is being referred to, so why is the first qui and the second ce qui and not qui in both situations?