SWINGING IN a hammock is the best way to guarantee good sleep, research has shown. The gentle rocking motion helps people nod off faster and sleep more deeply, say scientists who studied sleepers’ brainwaves.
“It is a common belief that rocking induces sleep: we irresistibly fall asleep in a rocking chair and, since immemorial times, we cradle our babies to sleep,” said Dr Sophie Schwartz, from the University of Geneva in Switzerland.
“Yet, how this works had remained a mystery. The goal of our study was twofold: to test whether rocking does indeed soothe sleep, and to understand how this might work at the brain level.”
For the study, 12 volunteers were asked to nap on a custom-made “experimental hammock” bed that could either stay still or rock gently. All participants were naturally good sleepers who did not typically nap.
Each took two 45-minute afternoon naps, one with the bed stationary and the other with it in motion. At the same time, their brain waves were monitored by electroencephalogram (EEG) electrodes attached to the scalp.
“We observed a faster transition to sleep in each and every subject in the swinging condition,” said co-researcher Dr Michel Muhlethaler, also from the University of Geneva.
The findings, published yesterday in the journal Current Biology, showed a "dramatic boosting" of certain types of sleep-related brain waves associated with rocking.