In New York, gyms, commitments to which swell every January before being forgotten by Presidents’ Day, can trace their history to a man named Friedrich Ludwig Jahn, who began teaching outdoor athletics classes in Berlin early in the 19th century. Jahn taught gymnastics on devices of his own invention: balance beams, parallel bars and so on.

Over several decades, gymnastics societies, Turnverein, whose members were called Turners, spread around Germany. The fitness centers that evolved functioned also as political clubs for those who supported democratic reforms in the German states. When a war came in 1848, many Turners fled to the United States, where they set up their athletic societies in New York, Philadelphia, Baltimore and other major cities. Politics played a part.

Every era gets the fitness culture it is meant to have. The aerobics craze, propelled by Jane Fonda, took off in the 1980s when the hedonism that distinguished the ’70s began to give way to a new urban ethic of busyness, long hours and the march toward more and more money. Beginning in the ’90s and continuing into this century, cities like New York and Los Angeles saw the rise of high-end gyms (David Barton, Equinox), which ensured that working out, like drinking coffee, would become another socially tiered experience with occupiers of top tax brackets doing it one way and secretaries and civil servants another — left to leg lifts in front of their televisions or discounted gyms that did not aim to make you feel special.

More recently we have seen the explosion of boutique fitness studios like Barry’s Bootcamp, Pure Barre and Soul Cycle, the last of which is now in virtually every neighborhood in Manhattan south of 96th Street, the Hamptons and other places around the country where real estate values send jolts through the collective nervous system of ordinary people. Soul Cycle, like certain iterations of yoga, has been such a success in the current moment in part because it makes submission to a luxury-brand experience feel like spiritual enrichment. On some level it aims to alleviate your guilt. The $34 you are spending on 45 minutes of stationary biking is going to improve you as a person, and the world, in turn, will be a better place for all of your growth.