1. One of the critical roles of a fitness instructor is technique. Not being able to correct it is a hazard.
2. There's no clear value for a fitness instructor. Selling phone workouts for $0.99 in the app store is unlikely to be as profitable as 20 regular clients paying $50/week for personal attention.
Ultimately, fitness instructors provide personal services. A few outliers, e.g. Richard Simmons, can brand and sell in bulk as celebrities. But most have to focus on client relations and high touch sales.
2. There's no clear value for a fitness instructor. Selling phone workouts for $0.99 in the app store is unlikely to be as profitable as 20 regular clients paying $50/week for personal attention.
Ultimately, fitness instructors provide personal services. A few outliers, e.g. Richard Simmons, can brand and sell in bulk as celebrities. But most have to focus on client relations and high touch sales.
Good luck.