This is definitely an issue that needs to be addressed by the individual’s accountant. That being said, usually the individual’s health care professional (primary care physician, cardiologist, etc) will need to prescribe said training in order for it to be considered a business or personal medical expense for tax purposes.
the answer is probably ‘yes’ but this should be addressed to the accountant of your client.
I’m not sure what you are trying to ask, but I had clients in the past who got reimbursed by their employer for some of their sessions they did with me. This was part of their company’s benefits provided to them. I don’t know anyone personally who was able to write off their PT sessions as a business expense. Maybe someone else in this forum might be able to provide you with more information.