Fix the leaks in the bucket.

The leaky bucket concept nicely explains why  attrition is painful and costly for gym owners. Imagine a bucket filled with water, representing your total member base. The water that pours into the bucket are your new members. The holes in the bucket are members who leave. If there are lots of holes and many members leave, even if you're continuously attracting new ones, your total member base will decrease (reducing your profit).   

To keep your gym thriving, it's crucial to patch up leaks, by creating rich member experiences that keep people engaged. It’s not rocket science. If people enjoy coming to your gym, they’ll keep come back (engaged). If they don’t enjoy coming, they leave (disengaged). When you have more new members joining than you have leaving, your gym profits grow.