About 25 years ago, a new concept emerged in exercise physiology. This involved cellular swelling or cell hydration. The first studies on this involved liver cells. Examination of the cells or hepatocytes showed that when the cells were replete with water anabolic processes within the cell were instituted. Conversely, when cells were dehydrated, catabolism or the breakdown of the cell ensued. Not long after this initial finding, the cellular swelling/anabolic effect was found to also exist in muscle tissue. Simply put, when your muscle cells are hydrated, anabolic effects dominate over catabolic or breakdown effects. Of course, this has implications for those involved in bodybuilding, sports, or any type of fitness activity, as well as general health. A loss of muscle with age, known as Sarcopenia, is considered a risk for impending mortality. So even people not involved in exercise, fitness, or bodybuilding activity would nonetheless want to keep their cells hydrated.
One type of training known as blood-flow restriction training (BFR) involves placing a cuff on the arms or legs near the muscles that are being exercised. This cuff partially restricts blood flow to the working muscle and promotes the accumulation of metabolic waste products that can induce muscular fatigue but are also now known to act as anabolic signaling factors in muscle. This is also known as Metabolic Stress, which is one of the three requirements for promoting muscular hypertrophy. The other two are muscular damage and mechanical tension within the trained muscle. The effect of restricting blood flow to trained muscles is so potent that muscular size increases can occur using as little as 20 to 40% of one-rep maximum weight. In contrast, with traditional training, the usual suggested minimal weight resistance used to promote increased muscular size and strength is 75% of one-rep maximum weight.
After completing a maximal low load, high repetition set that leads to muscular failure, intramuscular levels of ATP drop by about 30 to 40%. This is significant because ATP or adenosine triphosphate is the most elemental energy source in cells. All calories that you consume from any source, whether it's from protein, carbohydrates, or fats, are eventually converted into ATP in the mitochondria portion of cells. Creatine phosphate, which is creatine complexed with phosphorus, acts as a backup to ATP to help replenish ATP through contributing phosphate groups to the depleted ATP. But with continued exercise, creatine in muscle is also depleted. In the meantime, byproducts of muscle or ATP metabolism increase in muscle. These byproducts include ADP, AMP, adenosine, nitric oxide, and lactate. These metabolites are known to increase blood flow to working muscle, but the increased blood flow to muscle alone won't boost muscular hypertrophy. Instead, the accumulation of muscle metabolic byproducts along with increased acid production in the muscle by way of hydrogen ions, along with the lowered oxygen delivery to muscle caused by . . .