How it works

Exercise reduced stress signals and increased prefrontal cortical signals, Tawakol said.

“Both are attractive changes in the brain,” he said.

The prefrontal cortex is the part of the brain responsible for executive function, which are the cognitive processes that control behavior, Tawakol said.

And stress signals in the brain are associated with things like inflammation, higher sympathetic nervous system activity, higher blood pressure, and diseases that thicken or harden the arteries, he added.

In part, exercise appeared to reduce heart disease risks by reducing the stress signals, Tawakol said.

These findings are just associations, however. Because the researchers observed participants rather than conducting a randomized trial with a control group, they cannot say for sure that the exercise caused the reductions or what the mechanisms are that underlie it, he said.