People who struggle with sleep problems and insomnia are often told to exercise in order to slumber more soundly.
Yet, new research from the Northwestern University Feinberg School of Medicine indicates that it might take a few months of hitting the treadmill before the effects kick in.
In a 16-week study of older women with existing sleep problems, researchers found that it often took four months of consistent exercise before sleep improved, Counsel and Heal reported.
"If you have insomnia you won't exercise yourself into sleep right away," lead study author Kelly Glazer Baron, a clinical psychologist and director of the behavioral sleep program at Northwestern University Feinberg School of Medicine, said in a news release. "It's a long-term relationship. You have to keep at it and not get discouraged."
Despite the lag time, researchers say exercise is still the best solution for people suffering from insomnia.
"Patients with insomnia have a heightened level of brain activity and it takes time to re-establish a more normal level that can facilitate sleep," co-researcher Dr. Phyllis Zee said in a statement. "Rather than medications, which can induce sleep quickly, exercise may be a healthier way to improve sleep because it could address the underlying problem."