The body actively resists change and maintains its current state (homeostasis). To stimulate muscle growth, you must apply a stress greater than what it has previously adapted to, forcing it to reinforce itself. This requires a "bloody good reason" to change.

The standard 5-gram dose of creatine is effective for muscle performance but insufficient to saturate the brain. To leverage creatine's neuroprotective and cognitive-enhancing effects—such as improved function when sleep-deprived or aging—a higher daily dose of 10 to 15 grams is necessary.

Physical activity stimulates the release of Brain-Derived Neurotrophic Factor (BDNF), crucial for neuron growth, via two mechanisms. Muscles release a protein (a myokine) and the liver, in response to exercise stress, releases a ketone (beta-hydroxybutyrate). Both cross the blood-brain barrier to stimulate BDNF production.

A study on identical twins revealed that the twin with greater leg strength had a larger brain and better cognitive function over a 10-year period. This suggests that lower-body resistance training is a uniquely potent and specific intervention for preserving brain mass and preventing Alzheimer's.

High-stakes mental tasks are physically taxing; a top chess player can burn 600 calories sitting at a board. Physical conditioning is not just for athletes; it directly builds gray matter and enhances executive function, providing the stamina needed to make good decisions under cognitive stress in a professional environment.

While BDNF is associated with exercise's brain benefits, the BDNF produced in muscles doesn't readily cross into the brain. Instead, lactate produced during intense exercise enters the brain and acts as a signaling molecule, stimulating local BDNF production and improving hippocampal function.

A study requiring participants to perform a grueling HIIT protocol (4 sets of 4 minutes at 85-95% max heart rate) three times a week resulted in significant improvements in hippocampal structure and function. Remarkably, these benefits were maintained for several years after the trial ended.

A study on "low-fit" adults (exercising <30 mins/week) showed that starting a modest cardio regimen of two to three 45-minute sessions weekly for three months yielded significant cognitive benefits. This included improved performance on memory tasks classically dependent on the hippocampus, demonstrating a low barrier to entry for brain health.

Each workout releases a cocktail of neurochemicals, including dopamine, serotonin, and the growth factor BDNF. This "bubble bath" for the brain directly stimulates the growth of new cells in the hippocampus, making it larger and more resilient, which improves long-term memory and can delay dementia.