An airline for example; now everyone actually caches their flight because Google's self-driving cars always make it on time, and then they demand that Google stops bringing passengers on time?
Or a buffet restaurant, since now everyone goes to the gym, they can actually eat a lot more, thus restaurants complain about, either the gym or the pill maker?
I don't know, it would be a strange world to live in if this happened in other industries. Maybe prices would rise too much?
Fast forward 3 years later, you come out with your pill and throw a wrench in the works. Now gyms realize they have to go back to the old pricing model because the economics have changed. Consumers will no doubt become upset at the prospec of having to pay more. Some gyms take a wait and see approach to see what other gyms will do. Your pill started it but really, it's not your fault or your problem.
What should the gyms do?
Be Honest. They can invent a new business model based on transparency. Imagine if price is not fixed but you are charged per use based on the traffic at the moment. It could be similar to what Uber does, price based on demand.
In terms of ISPs, I think there should be a micro transaction exchange where I can buy X minutes of data transfer. If Verizon is clogged I switch my router to connect with ATT etc. All networks should create a single broker device thats given to each consumer.