Understanding Nike's tone of voice is a good start for understanding how sports brands communicate in general. While each brand has its nuances, at the end of the day, they're all about the same thing: inspiring people to move and encouraging them to buy products that facilitate that movement. Adidas, for example, is as direct and personal as Nike. Their mission statements are meant to push people to do exactly the same thing, like putting on their shoes and going for a run, dance, or whatever. Although Adidas tries to present itself as rawer or tapped into a culture (is debatable and, I’d say, more or less true in trend phases), the companies are ultimately very similar in what they do and their overall objectives.
Creatives are attracted to working on these brands because they like the idea that sports brands sell. Telling the consumer that they are capable of more. Next to selling products (of course), they sell something else: ambition, action, and the belief that everyone has an athlete inside them.