How do I become a wellness coach?

Some organizations require a four yr degree (in nutrition), or a certification, such as PT. I thought the PT would work, as a prerequisite. However, I would like to work with seniors, and am not sure if a senior trainer certification is what I should look into.i have an education degree with grad school experience, which is not useful for the most part in this arena. My son, the PT, says the certification provider (ACE, etc) is not an issue. I have spoken to so many people that I am now quite confused.