Insurance for provider of corporate wellness programs

Hello,
A great new company I'm working with, fitsteady.com, is in the business of helping people reach their fitness goals by intuitively matching people up with the right fitness instructor for them. Recently, we began working as the wellness partner for a number of local corporations, and one of our latest is requiring that we be insured on behalf of all of our instructors - all of whom we deal with as independent contractors and all of whom are fully insured. Does anyone have any idea about how we can structure this policy? Given that those who do the instruction are already insured and we would be mostly an umbrella for the group so that the company has a single policy to analyze as opposed to the collection of instructors?
Many thanks!
Brian