Wellness in the workplace isn’t just for large companies. Here’s how small businesses can build a culture of health.

Over the past decade, wellness has grown into a $4.2 trillion company. In the crowded market of self-improvement, hardcore health innovations jostling with softcore supplements in the jade egg domain. In the meantime, “busy” culture has a kind of work worship leaving many people burned out and wondering how much they should really expect (or give into) their job. Amid all this, well-being in the workplace is on the rise; more than 80 percent of large companies and 50 percent of small companies have implemented such programs. Despite their ubiquity, big questions remain about what exactly works.

That’s something that Dr. Ron Goetzel has devoted his career to. Goetzel is a senior scientist and director of the Institute for Health and Productivity Studies at Johns Hopkins, as well as VP of applied research for IBM Watson Health. He says the first idea worth considering is how we think about what “works.” Traditionally, the measure of success has been return on investment (ROI), or what a company saves on lower health care costs and less absenteeism, given how much they have invested in wellness initiatives. Goetzel does a lot of these analyses. It has been run since 1994 The health project, which awards an annual award to companies with demonstrably effective wellness initiatives. He led a recent study showing that a portfolio of 26 of these companies significantly outperformed the S&P 500 over a 14-year period. The 26 companies that truly invested in wellness achieved stock returns of 325 percent, versus the S&P 500’s 105 percent. Data suggests that well-executed wellness programs actually pay off.