Why do we call an effort to improve ourselves a “challenge?”

These days, it seems like everything that is supposedly good for us is often called a “challenge” such as diets, exercise plans, fundraisers, etc. Calling it a challenge encourages you to start doing it, but it also suggests that it will be difficult, mildly inconvenient and that you get to stop doing it one day. When you want to implement a self-improvement routine into your daily life, whether it be exercise, meditation or eating healthier, the idea is that you want it to be easy, practical and sustainable. So don’t give it a name, don’t make it a thing, just decide what you’re going to do and start doing it.