We spoke recently with our resident fatigue doctor, Dr. Doug Potter, who is one of the few people in his industry who balances both medicine and leadership skills. He works in environments that are risky and remote, helping management make smart choices for the health of their workers, and helping employees understand why one week they might feel energetic, yet the next week they can’t keep their eyes open.
It’s all a matter of timing, and management can use these simple tips about shift worker fatigue to keep it all straight.
Going from day shift to night shift can be managed. In my work with Predictive Safety, we have a countermeasure called “phase shifting” that instructs workers to stay up 90 minutes longer each day to adjust going from day shift to night shift. You’re essentially setting up a longer day, which is easier on an employee’s internal circadian clock than making the body reset itself backward by getting up earlier.
Going from night shift to day shift is harder. It is harder on your employees to go from the night shift back to the day. You need to give them approximately 48 hours to rest and reset so they don’t develop serious fatigue by the end of the workweek. They have to have nighttime sleep. Daytime sleeping is okay, but it’s not really restorative. If their last shift ended at 6 am then one extra night’s sleep isn’t going to cut it. You’re making their circadian clocks go backward, and the body can only adjust up to about 3 hours a day.
“If the employee’s last shift ended at 6 am then one extra night’s sleep isn’t going to cut it.”
Hours off aren’t the only factor. Where you run into a problem with only using shift scheduling to manage fatigue is when people have a hard time sleeping. Sleep apnea is an issue, but it’s not the only one and I get concerned when companies want to use it as a silver bullet that will take care of all fatigue issues. There are so many other factors that affect sleep quality. A spouse that snores, money troubles that keep you awake, a pet that moves around on the bed, noisy neighbors – the reasons are endless.
If they don’t get good quality sleep, then they literally develop “sleep debt”. When that happens, it doesn’t matter if they are working a day shift or night shift. 36 hours with only one extra night to restore their energy is just not going to be enough. After a regular workweek, they need at least 2 sleep periods – at night. You can’t count a day’s sleep as good restorative sleep.
Our predictive fatigue management system asks workers how much sleep they had the night before. It combines that with their work schedule history to arrive at a fatigue prediction that is quite accurate. If you don’t have something like that, then at least make sure your workers have the opportunity for sleep by following the two-night guideline.