Everyone's constitution is different. Some are naturally robust with excellent physical fitness, while others have inherently weaker constitutions, making them prone to illness and easily breathless from minimal exertion. This is highly undesirable. Can't those with weaker constitutions improve their health through effort? So how does exercise transform the body?
Enhanced Mental Function
The magic begins in the brain.When exercise begins, electrochemical signals are sent from the cerebral cortex, traveling through neurons to the junctions where they meet muscle fibers.
Exercise increases blood flow to the brain, prompting brain cells to operate at a higher level. This makes you more alert and awake during activity, with enhanced focus.Regular exercise repeatedly triggers this surge in blood flow and neural stimulation. These changes enhance brain function while preventing diseases and slowing aging—including Alzheimer's, Parkinson's, and even stroke. Fat loss and muscle gain During exercise, the body initially relies on glycogen for energy. After 20 minutes, when glycogen reserves are depleted, fat is mobilized for fuel.Therefore, to burn fat, the duration of exercise is key—the longer you exercise, the more fat you burn. Moreover, once fat becomes the primary fuel source, your body's energy levels surge rapidly. In the first 20 minutes, burning 1 mole of glycogen produces 2 moles of ATP. However, during aerobic metabolism involving fat, burning 1 mole of fat generates 120 moles of ATP. This is why you feel a surge of energy after exercising for a while.
Improved Gastrointestinal Digestion
During exercise, as the body redirects more blood to muscles, certain systems and functions deemed non-essential receive reduced blood supply—such as digestive absorption in the gastrointestinal tract.
However, the intestines possess abundant smooth muscle tissue, leading to increased peristaltic activity.
Enhanced Kidney Water Metabolism
During exercise, the kidneys filter blood faster and absorb more water to help the body retain fluids. Simultaneously, adrenal secretion increases, releasing more stress hormones and elevating adrenaline levels. This accelerates the heart rate, enabling the heart to pump more blood throughout the body.
Skin becomes smoother
After exercise, the body generates heat like any engine and requires cooling. The skin manages this process. Skin blood vessels rapidly dilate, increasing blood flow to the skin surface. As skin temperature rises and perspiration increases, heat dissipates through sweat into the air, simultaneously expelling bodily waste products.
Stronger heart
During exercise, increased heart rate accelerates blood circulation, delivering more oxygen throughout the body at a faster pace. While resting, the average person's cardiac output is about 5 liters per minute; intense exercise can boost this to 30 liters per minute, enhancing the elasticity of your heart's blood vessels.Scientists studying renowned marathon runner Clarence Dema discovered his coronary arteries were larger than average, a benefit of his lifelong training. Exercise also stimulates new blood vessel growth, helping prevent high blood pressure. Lung capacity increases When exercise begins, blood vessels in the lungs dilate, breathing rate increases, and breaths become deeper.Since the number of alveoli and lung volume remain constant, obtaining more oxygen requires mobilizing additional alveoli. Typically, we utilize less than one-third of our alveoli, with a ventilation rate of only 6 liters per minute. During intense exercise, as more alveoli become active and breathing accelerates, ventilation rapidly increases, reaching a maximum of 120–150 liters per minute. This helps strengthen your lung function.
Increased bone density
Bone mass peaks in adulthood before gradually declining. Exercise helps maintain a higher peak density and slows this decline.During exercise, joints and bones bear 5–6 times your body weight, stimulating bone cells to multiply significantly and thereby increasing bone density.
Weight-bearing exercise is particularly effective in counteracting osteoporosis.