As most of us know all too well, the workday never really "ends" anymore.

Even once you're at home in your pajamas, there's always the temptation to check your work email one more time or listen to a voicemail from a client that just came in.

While it may feel like a relief to know that you won't miss anything important, the problem is that never truly shutting off may have some serious consequences for your mental and physical health.

That's according to a recent study led by Jan Dettmers at the University of Hamburg and published in the Journal of Occupational Health Psychology.

For the study, cited this week on Scientific American, the researchers looked at 132 employees (mostly men) in a range of occupations, from transport and logistics to IT and technical services. All participants had certain times when they were required to be "on call," which means they had to be available outside regular working hours to deal with customer requests and other urgent issues.

To measure the specific effects of on-call periods, the researchers focused on a few days when participants were on call and a few days when they worked regular schedules.

Every morning, participants were asked to fill out a survey about their mood, answering questions about their energy levels and calmness. And every evening, they were asked to fill out a survey about their level of detachment--or how often they thought about work.

The researchers also measured participants' morning levels of cortisol, a stress hormone.

Sure enough, on mornings after on-call days, participants were typically in a worse mood and their cortisol levels were higher compared to mornings after regular work days.

Interestingly, it didn't matter whether the participants had actually dealt with any work demands during their on-call period. That finding led the researchers to suspect that it was simply the anticipation of having to handle work issues that affected their mood and stress levels.

Another analysis showed that the impact of on-call periods depended partly on participants' level of detachment. Those who were able to basically stop thinking about work once they got home were less stressed and in a better mood after on-call days than those who couldn't put a stop to their thoughts.

Of course, participants in this study had formal on-call periods, whereas many of us simply feel obligated or are expected to answer emails and phone calls after regular hours. For that reason, these findings don't necessarily apply to everyone.

Yet the takeaway here seems to be that having time to recover from the workday is more important than we might believe. If we're always "on," our wellbeing may suffer -; and it's likely that our performance could decrease in turn.

At the same time, it may not be possible--at least not immediately--to change your manager's expectations about your after-hours availability. A more practical solution may be for you to adopt different coping strategies, like trying to divert your thoughts from work-related issues once you get home, since the participants who said they stopped thinking about work were less stressed than those who continued obsessing.

If you feel like it's really impossible to get some distance from the workday, consider talking to your manager about the situation. If you explain that you'd be more productive if you got a few hours where you weren't expected to be available, they may be more sympathetic than you'd think.

This story first appeared on Business Insider