Exercise and Fitness for All Act of 2021 This bill requires the Architectural and Transportation Barriers Compliance Board (Access Board) to develop guidelines for exercise or fitness service providers regarding the provision of accessible exercise or fitness equipment. The Access Board must subsequently promulgate regulations, consistent with the guidelines, requiring that exercise or fitness classes and instruction provided by fitness providers are accessible to people with disabilities. The regulations also must require that each provider make at least one employee available to assist people with disabilities with using the accessible exercise or fitness equipment.