Heart Ion Concentrations... blood electrolyte (ion) balance is important for stable cardiac performance. Imbalances in heart ion concentrations are known to cause the heart rhythm and rate disturbances during cardiac arrest (heart attack). All indicators are that Body'Fit pH Fitness has the unique ability to maintain optimal heart electrolyte concentrations even as heart rate reaches training levels.

Increased concentrations of K+ that occur during most exercise can cause heart block, ventricular fibrillation, asystole and reduced heart rate. Body'Fit pH Fitness can be utilized to optimize the amount of Na+, K+ and Ca++ that allow the heart to function normally under all training conditions. Otherwise elevated concentrations of Na+ inhibit inflow of Ca++ which reduces cardiac rate as limits of exercise are reached. Alterations in plasma Ca++ concentrations cause variations in cardiac rhythm and rate.

In the absence of Na+, the heart is not excitable and will not beat because the electric action potential depends on the presence of extracellular Na+ ions. A severe reduction in extra cellular K+ weakens and paralyzes the heart, and a moderate reduction flattens the T-wave, while large increases produce depolarization, loss of excitability, and cardiac arrest. A modest increase in Ca++ increase enhances contractile force, and a very high increase induces cardiac arrest in systole. Removal of extracellular Ca++ reduces contractile force and causes arrest in diastole. The concentration of free Ca++ is responsible for the contractile state of the heart muscle. Mechanisms that raise systolic Ca++ increase the developed force and those that lower Ca++ decrease the developed force. Catecholamines increase the movement and sensitivity of the cells to Ca++. An increase in systolic Ca++ is achieved by increasing the extracelular Ca++ or decreasing the Na+ gradient across the sarcolemma. The sodium gradient can be reduced by increasing intracellular Na+ or decreasing extracellular Na+.