Sport trains bodies for work while pretending fitness is its own end.

Evidence

The accepted reason for playing sport is that it makes believe that fitness itself is the sole, independent end of sport: whereas fitness for work is certainly one of the covert ends of sport. Frequently it is in sport that people first inflict upon themselves (and celebrate as a triumph of their own freedom) precisely what society inflicts upon them and what they must learn to enjoy. — Theodor W. Adorno, The Culture Industry, 266

Categorization

• XREF: Directly extensible to modern wellness culture and biohacking — the gym rat ‘optimizing’ themselves as labor. Also parallels how the culture-industry apparatus trains obedience under the guise of freedom.
• SEED: An essay angle: run this exact move on gamified fitness (Strava, Apple Watch rings) — public fitness-as-productivity celebrated as self-care.