This begs the question: 277% more effective than what?
Other Pilates machines? Ordinary Pilates with no equipment? Sit-ups? Going to the gym? Richard Simmons?
The rule in writing is that when you compare something, you have to say what you are comparing it to.
My rewrite: “Zones Pilates are 277% more effective than doing ordinary Pilates.”
Now, isn’t that better?
Or do you think implied in the statement “277% more effective” is the idea that it is more effective than ordinary Pilates — and that it’s so obvious, it doesn’t need to be stated?