Phosphorus for Sports & Fitness

The use of alkalinizing agents, such as sodium bicarbonate, sodium citrate, and phosphate salts (potassium phosphate, sodium acid phosphate, and tribasic sodium phosphate) to enhance athletic performance is designed to neutralize the acids produced during exercise that may interfere with energy production or muscle contraction.¹ Some double-blind studies, though not all, have found that sodium bicarbonate or sodium citrate typically improves exercise performance for events lasting either 1 to10 minutes or 30 to 60 minutes.^{2, 3, 4, 5, 6, 7, 8, 9, 10} The amounts used are 115 to 180 mg of sodium bicarbonate or 135 to 225 mg of sodium citrate per pound of body weight. These amounts are dissolved in at least two cups of fluid and are taken either as a single ingestion at least one hour before exercise or divided into smaller amounts and taken over several hours before exercise. Performance during periods of less than one minute or between 10 and 30 minutes is not improved by taking alkalinizing agents.^{11, 12, 13, 14, 15} Sodium citrate may be preferable to sodium bicarbonate because it causes less gastrointestinal upset.¹⁶ Another alkalinizing agent, phosphate salts, has been investigated primarily as an endurance performance enhancer, with very inconsistent results.^{17, 18}

People with severe kidney disease must avoid excessive phosphorus. Based primarily on animal studies, some authorities have suggested that excess intake of phosphate is hazardous to normal calcium and bone metabolism,¹⁹ but this idea has been challenged.²⁰ Phosphoric acid–containing soft drinks have been implicated in elevated kidney stone risk,^{21, 22} but not all studies have found this relationship.²³

Ingestion of excessive amounts of aluminum-containing antacids (such as Di-Gel®, Riopan®, Maalox®, or Mylanta®) can cause phosphorus deficiency.

High phosphorus intake may impair absorption of iron, copper, and zinc.²⁴Ingestion of excessive amounts of aluminum-containing antacids (such as Di-Gel, Riopan, Maalox, or Mylanta) can cause phosphorus deficiency.

Phosphorus is highest in protein-rich foods and cereal grains. In addition, phosphorus additives are used in many soft drinks and packaged foods. Phosphorus is not often present in supplements except for certain calcium supplements, such as bone meal.