#ThankGodIt’sMonday! This is the rallying cry of a new movement of work obsessives, according to a widely shared opinion piece on “performative workaholism” in the New York Times. These ergomaniacs encourage each other to “hustle harder”. They drink from water coolers containing floating cucumbers carved with pro-work slogans, such as “Don’t stop when you’re tired, stop when you’re done.”

“No one ever changed the world on 40 hours a week,” Elon Musk, the patron saint of the #TIGM movement announced on Twitter. Musk recommends “80, sustained’” hours a week, “peaking [at] about 100”.

We haven’t always been so work-obsessed. During the middle ages in England, peasants could work just 150 days a year. Until relatively recently, work was seen as painful toil, and best avoided. But something changed in the 16th century – we started to think that work was morally good. Five hundred years on, #ThankGodIt’sMonday has made it saintly. Now we have a Protestant work ethic without the pressure of taking Sunday off to go to church. Instead, we should toil 24/7, taking #workinglate selfies to prove it.

But is putting in long hours any good for us? We know that not working can make us miserable. People who work tend to be healthier. Work can give us a sense of purpose and meaning. It connects us with other people. At a minimum, work provides money as well as something to do with our time.

But too much work can be toxic. Working very long hours can be bad for our health. Ultra-long hours can kill. Ergomania can lead to problems such as depression, anxiety and addiction and can cut us off from friends and family, leaving us with only colleagues. If work disappears, work obsessives often have nothing to fall back on. A job loss can become a deep existential crisis.

Instead of boasting about the hours we work, we would be better off listening to Bruce Daisley, an executive at Twitter: “Go to lunch,” “Get a good night’s sleep,” and: “Shorten your work week.