A bath 90 minutes before bed could be the secret to a good night's sleep

Scientists have found that relaxing in warm water before bedtime will help you get to sleep faster and improve overall quality

Scientists have found that a bath 90 minutes before going to bed could be the key to a good night's sleep.

Researchers at the UT Health Science Center at Houston and the University of Southern California analysed more than 5,000 studies that explored the relationship between bathing, or showering, and sleep-related conditions.

The biomedical engineers found that a bath between 40°C and 42°C could increase the speed of falling asleep by ten minutes.

“When we looked through all known studies, we noticed significant disparities in terms of the approaches and findings," said Shahab Haghayegh, the lead author on the study.

"The only way to make an accurate determination of whether sleep can in fact be improved was to combine all the past data and look at it through a new lens."

Both sleep and the body’s core temperature is regulated by the circadian clock, an internal 24 hour rhythm located in the brain’s hypothalamus that determines the sleep-wake cycle.

On average body temperature is 2-3 degrees higher in the late afternoon, or early evening, than during sleep.

But as the body’s temperature rises while sleeping, it can disrupt the sleep and act as a biological alarm clock.

The researchers believe that taking a bath an hour and a half before bed will stimulate blood circulation from the internal core to the hands and feet, in turn, causing a drop in body temperature.

“Therefore, if baths are taken at the right biological time – one to two hours before bedtime – they will aid the natural circadian process and increase one's chances of not only falling asleep quickly but also of experiencing better quality sleep,” said the paper.