It started before Soul Cycle, an underground movement with small groups of exercise enthusiast turning up to workout together. They shared a common desire to train hard, suffer together rather than alone, motivate each other and recognise individual and group achievement. They shared a common goal. Maximize the workout and share the experience.
It began with small studios and enthusiastic instructors and then it gained momentum. The industry looked at it as a fad, something on the periphery, a small group of enthusiastic spinning participants, yoga devotees and Olympic lifters.
Then when Soul Cycle was revelaed, $112 million in anaual sales, people took notice. On the surface it looked easy to replicate. Take a small space, give it a funky appearance, coin a unique training approach and charge by the class not by the month.
Create a quality workout and user experience, make sure you can deliver it to those same high standards over and over again, price it above the norm...