Morning grogginess could be more dangerous than feeling drunk for shift workers, according to recent research.
The dozy feeling experienced after waking up after eight hours’ sleep damages the thought processes even more than 24 hours of sleep deprivation or several hours of drinking alcohol, scientists have warned.
“This is the first time anyone has quantified the effects of sleep inertia,” professor Kenneth Wright from the University of Colorado said.
“We found that cognitive skills of test subjects were worse upon awakening than after extended sleep deprivation.”
Many public sector workers, including medical staff and firefighters, could be at risk when performing critical tasks while suffering from sleep inertia, according to the study.
“For a short period at least, the effects of sleep inertia may be as bad as or worse than being legally drunk,” Wright said.
The researchers monitored volunteers for six nights and found that grogginess was apparent for up to two hours after waking.
But the most severe effects of sleep inertia generally started to go away within the first 10 minutes.
The researchers have called for more studies to measure the effects of nap interruption and ‘recovery sleep’.