Exercise

Doctors increasingly view exercise as the single most powerful medical intervention available. Observational studies suggest one minute of exercise correlates to an additional five minutes of life as humans age. Stanford researcher Euan Ashley discusses our current understanding of how exercise provides benefits at the cellular level.

Exercise has dramatic effects on human biology, including reducing some of the long-term harms associated with chronic stress. Its effects are also pronounced in the brain, including improved memory retention, sleep, cognitive functioning, and more.

Cardiovascular exercise has been found to boost the gut's population of beneficial bacteria, and exercise overall decreases the likelihood of developing a "leaky gut," a condition in which a porous gut lining allows bacteria to leak into the bloodstream and cause inflammation.

Placing muscle under increased load or stress causes damage that requires rest to repair, leading to stronger, more enduring muscle over time. Muscles adapt to such increasing demands by improving their efficiency with approaches that include increasing the number of mitochondria housed in hundreds of thousands of muscle cells.

Physical activity can turn beneficial genes on and harmful genes off, without altering the underlying DNA code. This engaging article explains the epigenetic mechanisms that take place with exercise and ultimately result in improved metabolism, lower inflammation, and optimized brain function.

When we want to move a muscle, a signal travels from the brain and into the muscle cells in question, sparking a chemical reaction that causes the muscle's smallest contractile units—sarcomeres—to shorten, forcing the muscle to contract.

VO2 max is the maximum rate at which the body can use oxygen to aerobically produce energy—adenosine triphosphate—for use during intense exercise. Aerobic exercise increases VO2 max, counteracting age-related decline by increasing the body's capillary count and remodeling the heart's left ventricle, increasing the amount of blood it pumps.

The origins of modern progressive resistance exercise are traced to ancient Greece, where a repeat Olympic victor carried a calf every day until it grew into a full-sized cow. This 56-minute comedy and history podcast journeys through the rise of modern bodybuilding, which took off during the 19th century.

Modern fitness stems from the revolution in the knowledge we have of the human body, its cardiovascular systems, how muscles work, and more. Nonetheless, people through the centuries have had fitness regimes—including one university student whose fitness plan was preserved in an obscure document found between a manuscript.

Prolonged inactivity, like sitting for long periods, slows metabolism, weakens muscles and bones, and impairs insulin function. When these negative changes persist over time, the cumulative result is an increased risk of cardiovascular disease, diabetes, and many cancers.