How Does Exercise Make You Better At Handling Anxiety?
Researchers have long wondered how exercise affects our brain. They became especially interested since it was discovered that exercise not only prompts the creation of new brain cells which are known to be very excitable, while also creating an overall pattern of calm in other areas of the brain.
When neurons are created they are often very excitable and can activate at the slightest stimulation, which is very useful for quick thinking and memory, but it can also be an issue with handling stress. The average stress a person deals with everyday is far from a life or death level situation, having a large amount of these young, excitable neurons going off at the same time can cause excess stress.
As the New York Times reported, animal studies have shown that physical exercise does in fact create these excitable young neurons in abundance, especially in the hippocampus, the portion of the brain associated with thinking and emotional responses. But, to researchers confusion, exercise has also been shown to reduce anxiety in human and animal trials.
Princeton researchers sought to answer that question with a study of mice, published in The Journal of Neuroscience, in which half of the mice were allowed to run on wheels at their desire, and others who were not allowed access to exercise and sat quietly in their cages.
The mice who were allowed to run showed signs of newborn, volatile cells, as well as an abundance of excitable neurons, but there was also a significant presence of another type of neuron specifically designed to release a neurotransmitter GABA, which inhibits brain activity, keeping certain neurons from easily firing. These neurons simultaneously calmed the brain while useful cells were being created, keeping them from going off unless they were really needed.
To understand how these neurons were functioning, the scientists then exposed the remaining mice in ice-cold water for five minutes, inducing stress and anxiety in non life-threatening levels. They then inspected their brains for markers that neurons had recently fired, which they found in abundance in both the runners and the sedimentary mice. These markers indicated the mice had all clearly undergone fair amounts of stress.
The mice who were allowed to run however, also showed evidence that stress activated the neurons which released GABA in large amounts, calming the mice after the event and keeping unnecessary anxiety maintained.