One of the first things I saw when opening up the PiYo website was the yoga asana known as the Warrior pose (which is identified with the yogic worship of Lord Virabhadra.) But that didn't surprise me because the name of the workout clearly informs the user that it is a combination of pilates (Pi) and yoga (Yo).
According to the site, the only difference between PiYo and traditional yoga and pilates is that PiYo is performed in fast sequences that add a cardio element to the workout which they say increases weight loss.
This is true, but what isn’t true is that you need to incorporate a Hindu spiritual practice into your routine to burn fat. No one needs yoga for anything that they can’t get from somewhere else. It’s a fad that is having negative spiritual effects on practitioners and really needs to go back to where it came from – India.
As for pilates, this exercise practice is not problematic although, as is the case with PiYo, many of the instructors combine it with yoga. If signing up for a pilates class, make sure it’s strictly pilates that has not been "yogafied".