"Fr. John Riley, chancellor for the Archdiocese of Kansas City, told The Wichita Eagle in an email that yoga is more than breathing and stretching because of its ties to Hinduism, with the objective being to achieve spiritual purity and divine union."
"It is for these reasons that Catholics are alerted to the dangers of the practice of yoga and are encouraged to look for other exercise alternatives that do not incorporate a spiritual dimension," he said."

Then Cardinal Ratzinger wrote in his 1989 Letter to the Bishops of the Catholic Church on Some Aspects of Christian Meditation that practices of meditation of the great non-Christian religions can be "a suitable means of helping the person who prays to come before God with an interior peace” (#28). 

Looks like Fr. R. did not do his homework before making his statement.