He works at Mayo. Mayo docs are very data driven. He said there was not enough research on the use of vests. Also he was worried that if I bent over while wearing a weighted vest, I would fracture.

@ninglike If osteoporosis is severe or there are already spinal fractures, the weighted vest might stress the spine and even cause fracture, I have been told. Check with your doctor! If you have osteopenia or mild osteoporosis, I would definitely go with what the doc says (and the risk may be much less).