Sounds like new age xian bullshit to me. Besides if your working out you are preparing your body for the kundalini rising and you need every edge you can get when doing so.The Kundalini rising is no small feat and you need to be in prime condition when it happens or it may be unbearable. Train your body, mind, and soul for this epic event. Hail Satan!!!
Define "prayers".
if by "prayers" you mean affirmations, then yes, they can help, but if you really want to lose weight you should undertake a good diet, Hatha yoga an Qigong
Ask here https://groups.yahoo.com/neo/groups/SSHealth/info
and read this