Researchers now suggest a simple form of therapy that could help people improve their sleep quality. Full-body cryostimulation, which involves exposing the body to extremely cold temperatures, may offer a solution for those struggling with sleep issues.
A recent study found that individuals who underwent daily cryostimulation, spending five minutes in a chamber cooled to -90°C, showed improvements in sleep quality after just five consecutive sessions. There was a marked difference in how men and women benefitted from the therapy, with women experiencing greater improvements than men.
"The use of cold for therapeutic purposes goes back to ancient Greece. But we still don't know the exact amount of cold needed to produce sleep benefits," said Olivier Dupuy, a researcher of the study in a news release.
During the trial, 20 participants: nine women and 11 men, underwent daily cryostimulation for five days. After exposure to the cold, the participants went about their normal daily activities until bedtime, avoiding alcohol and other factors known to affect sleep.
Their physiology and sleep patterns were monitored using brain activity sensors, a wrist actigraph, and heart rate sensors. Additionally, participants' perceived sleep quality was assessed using a questionnaire the following morning. To assess the effect on sleep, participants repeated the trial without cryostimulation.
"Our sleep architecture analysis revealed a significant increase in the duration of slow-wave sleep during nights following cryostimulation compared to nights without cryostimulation. Slow-wave sleep, considered the most restorative phase of sleep, increased by an average of 7.3 minutes during the first two sleep cycles," Dupuy said.
One important finding was that a single cryostimulation session was not enough to improve sleep; the benefits only appeared after five consecutive sessions.
The researchers noted that after three or four therapy sessions, the perceived sleep quality of women improved from an average of 3.4 to 3.9 and their perceived level of anxiety decreased from 43 to 38.
"Women and men did not have identical responses. This suggests that the dose of cold should be adjusted according to gender, although this requires further study," Dupuy added.
Although the study focused on individuals without sleep issues, the researchers believe cryostimulation could be particularly beneficial for those with sleep problems.
In addition to improving sleep quality, researchers suggest cryostimulation may help athletes recover from injury and could benefit people with chronic inflammation or mild dementia.
