Being physically active might help people with bipolar disorder fight off depressive symptoms.
Around 4.4 percent of adults have bipolar at some point in their lives.
Depression is even more prevalent, both in the U.S. and across the globe.
In fact, about 8 percent of people over the age of 20 in the U.S. have depression, according to the Centers for Disease Control and Prevention (CDC).
With 300 million people living with depression, the World Health Organization (WHO) describe it as the "leading cause of disability worldwide."
New research may help alleviate depressive symptoms, particularly in people with bipolar disorder.
A team led by Vadim Zipunnikov, Ph.D. — an assistant professor in the Department of Biostatistics at the Johns Hopkins Bloomberg School of Public Health in Baltimore, MD — found that increased physical activity improves mood and energy levels for those living with the condition.
How physical activity affects mood
Zipunnikov and colleagues asked 242 participants, aged 15–84, to wear activity tracking devices and keep electronic diaries of their mood and energy over the course of 2 weeks.
The participants — 150 of whom were female — used the diary four times per day to assess their perceived energy and mood using a seven-point scale that ranged from "very tired" to "very energetic" and from "very happy" to "very sad."
The researchers accounted for each individual's daily routines and designated four time points throughout the day: one in the morning, one at lunch, one at dinner time, and one at bedtime.
Overall, the study found that higher physical activity at any one of these time points correlated with better mood and higher energy levels at the following time point throughout the day.
The correlations also worked the other way around, meaning that higher energy levels at one point in the day were associated with higher levels of physical activity at the next time point.
These beneficial effects were strongest in a subgroup of 54 study participants who had bipolar disorder.
Also, the new research found that more physical activity was associated with a shorter sleep duration that night, but more sleep correlated with less physical activity the following day.
As the authors explain, examining sleep, physical activity, mood, and energy all at the same time is highly important for people with bipolar disorder because both sleep and activity influenced the participants' psychological well-being.
According to Zipunnikov, "Systems regulating sleep, motor activity, and mood have typically been studied independently. This work," he goes on, "demonstrates the importance of examining these systems jointly rather than in isolation."
He adds that the study "exemplifies the potential for combining the use of physical activity trackers and electronic diaries to better understand the complex dynamic interrelationships among multiple systems in a real-time and real-life context."
Zipunnikov and colleagues conclude, "These findings suggest that interventions focused on motor activity and energy may have greater efficacy than current approaches that target depressed mood."