Exercise increases energy and focus by triggering adrenaline release, which stimulates norepinephrine release in the brain.

“A brain-to-body-to-brain “arousal loop”. Movement= energy.”

“Exercise does indeed give you energy. It burns caloric energy, but it gives you neural energy by way of increasing epinephrine transmission from locus coeruleus. And presumably if the exercise is intense enough, adrenaline, epinephrine release, from the adrenals within your body, as well.”

“exercise gives us energy when we move our body the adrenals release adrenaline and the adrenaline acts through two different so-called parallel Pathways within the body but again it doesn't cross the bloodb brain barrier so then there's a series of what we call signaling relays or circuit relays up to the locus culus and then a sort of analog it's different but an analog to epinephrine norepinephrine is released within the brain and lo and behold we have elevated levels of both bodily energy and brain energy in Focus”

“There is absolutely nothing trivial about using exercise as a way to stimulate a sort of cascade of this neural circuit from the adrenals, up the vagus, and into locus coeruleus, in order to wake up your brain networks that are involved in motivation, focus, and learning.”

“He discovered that the brain areas that control movement of the large musculature, when those become active, they actually activate the release of adrenaline when we move. And the adrenaline then feeds back on those circuits.”