The marketing seems to assume your customer are knowledgeable athletes who want an app to track their performance. I would introduce two more user personas. The first is the type whose New Year resolution is either to lose weight or build stamina. Your app should suggest a program like a personal fitness trainer, show them what to do, and track their progress and give them encouragement when they achieve some milestone. The second user has a specific goal but need help coming up with a realistic training plan For example, they want to pass the new Army fitness standards.
https://armypubs.army.mil/pub/eforms/DR_a/ARN35762-DA_FORM_7...