Workouts like P90x and ClassPass are increasingly popular for promising to help sculpt a desirable body. They both promote and utilize the theory of muscle confusion, which states that in order to get results, your muscles need to become “confused” by switching up the exercises. This prevents your muscles from adapting and plateauing. Though, despite the workout regimens’ enduring popularity, some experts purport that muscle confusion doesn’t actually work. 
In order to shed fat and gain muscle, the body needs to do something called “progressive overload.” This means that in order to get the results you’re after, you will have to constantly push your limit. This means progressively lifting more weights or working out for longer periods of time. 
Many people who embark on muscle confusion-based workouts do end up seeing results, but some are saying that this is merely because workouts become progressively more difficult as the program continues.
But why does the muscle confusion myth endure? Many believe that it is partly because people have short attention spans. Doing the same workout every day and gradually increasing it can be boring to the majority of people. Therefore, muscle confusion offers the variety that makes people want to stick with the program until they begin to see results.
And while muscle confusion may be less-than-accurate, it is still undoubtedly profitable. P90x has sold more than 5 million copies of its program. ClassPass, a popular muscle confusion-based workout system, brought in over $60 million in revenue in 2015 alone.
Brett Bartholomew, CSCS*D, director of performance at Unbreakable, a Los Angeles gym, says of the popular myth:
“All the crap you hear about your body needing a different stimulus each week or a new ‘workout of the day’ is garbage. The number-one reason people don’t get results is that they don’t have the attention span to stick with something.” 
There are certainly many systems that will yield results in the fitness arena, but one thing is certain: for those who want to reap the rewards of their new bodies, patience may be difficult, but it is key. It can take months, or even years, of hard work and dedication to get the body you’ve been looking for. But with the proper motivation and glimpse into the future-you, these goals are surely attainable.