The first fitness class I went to was led by a 6-foot-2 non-union actor with bandannas tied around his forehead and bicep who for 50 minutes badly impersonated a military drill sergeant. "You're here to work!" he'd shout between whistle blows, shaking his head at a 14-year-old girl's sorry attempt at a burpee. It was 1999 and boot camps were springing up all over Los Angeles. The most in-demand instructors yelled the loudest.
While CrossFit and Tough Mudder are strongly carrying the pain-is-gain fitness dictum, elsewhere the fitness landscape is looking unprecedentedly...lazy. Cardio classes are offered in 20-minute sessions, restorative sessions run a full hour, and the most popular fitness apps don't track calories burned but REM cycles.