A recent study concluded that taking a 5-minute bath in cold water can improve moods of pleasure, pleasure, and fulfillment, as well as reducing anxiety and worry. The results were published in Biology.
In recent years, swimming outdoors and taking cold showers have become more popular. People who engage in them generally believe that they are beneficial to their health and that they improve their well-being. Recent studies have more or less established that cold water exposure has an effect on the body's immune system and motor functions.
Other studies have demonstrated that regular swimming in cold water can reduce fatigue, alleviate depressive symptoms, and enhance general well-being. Researchers have demonstrated that cold water immersion can improve mood and increase positive emotions. On a biochemical level, exposure to cold water results in the release of neurotransmitters like serotonin, dopamine, and norepinephrine, which play important roles in regulating emotions, stress, and processing rewards.
Ala Yankouskaya of Bournemouth University and her colleagues wanted to know how the mood swings resulting from cold water immersion might be linked to altered brain connectivity and interactions between different large-scale brain networks. They studied this phenomenon using magnetic resonance imaging (MRI).
39 adult participants participated in the study, which was marketed on university campuses and social media platforms (Facebook and Twitter). The participants had to be free of chronic pain, not using medication, have no history of chronic health disorders, not be pregnant, and not have participated in cold water immersion in the previous 12-18 months.
Participants completed an emotional assessment before doing resting-state MRI scans of their brains and a 2-minute electrocardiogram to measure heart activity. After that, they immersed themselves in a cold bath (19.93C 0.13C) up to their collarbones for five minutes.
After drying and dressing up, they went back for an MRI scan and completed the emotional assessment once more. As a reward for their participation, each participant received a 20 GBP (around $25) Amazon voucher.
The results of the study demonstrated that the cold water bath significantly increased the participants' heart rate, and their breathing volume remained constant throughout the bath. Participants reported feeling more positive emotions and less anxious after the cold water bath compared to before.
Two clusters of brain connections that showed significant changes were identified in the MRI data analysis.
"When we perform daily tasks, all of the tiny brain parts are connected to each other in a certain pattern," Yankouskaya said in a press release. "We saw physiological effects—such as shivering and heavy breathing. The MRI scans then showed us how the brain rewires its connectivity to help the person cope with the shock."
The first cluster reflected a greater connectivity between the medial prefrontal cortex and several sections of the salience network. Specifically, there was a stronger coupling between the medial prefrontal cortex and the left anterior insula, the left rostral prefrontal cortex, and the left lateral parietal part of the default mode network.
The default mode network is active during restful sleep and is associated with self-reflection and processing internal thoughts and memories. The salience network is involved in recognizing and directing attention to important stimuli, integrating sensory and emotional information, and aiding cognitive control processes.
After cold-water immersion, the second cluster consisted of positive connections between the frontoparietal network's posterior parietal cortex (associated with attention and cognition), the dorsal attention network's right inferior parietal sulcus, and the right visual lateral network.
The reduction in negative emotions was not linked to changes in brain connectivity. The medial prefrontal cortex and the rostral prefrontal cortex are involved in attention control, emotion, and self-regulation.
“These are the brain parts that control our emotions, help us stay alert, and help us make judgments,” Yankouskaya said. “We expected to notice changes in the connection between these components when participants commented on their feeling more alert, excited, and generally better after their cold bath.”
The research contributes to the scientific investigation of the effects of cold water immersion. However, the study did not include a control group. Also, the literature does not provide complete information on minute details about the brain networks involved.
Ala Yankouskaya, Ruth Williamson, Cameron Stacey, John James Totman, and Heather Massey collaborated on a short-term head-out whole-body cold-water immersion study.