Phosphorus for Sports & Fitness
Phosphorus is an essential mineral that is usually found in nature combined with oxygen as phosphate. Most of the phosphate in the human body is in bone, but phosphate-containing molecules (phospholipids) are also important components of cell membranes and lipoprotein particles, such as HDL and LDL (“good” and “bad” cholesterols, respectively). Small amounts of phosphate play important roles in numerous biochemical reactions throughout the body.
Why Do Athletes Use It?*
Some athletes say that phosphorus helps improve endurance.
What Do the Advocates Say?*
Phosphate is an important component of the high-energy compounds essential for muscle function, as well as compounds that participate in oxygen delivery to muscle. Phosphates can also act as acid neutralizers, which might have effects on fatigue. Some studies have shown that phosphate supplementation improves endurance performance, but others have not.
How Much Is Usually Taken by Athletes?
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.2,3,4,5,6,7,8,9,1 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.11,12,13,7,9 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