Low Zinc Intake May Sap Exercisers' Energy
(NY, Reuters Health, 6/3/05)

Henry C. Lukaski of the U.S. Department of Agriculture's Human Nutrition Research Center in Grand Forks, ND, and team, put 14 active young men on a low-zinc diet for 9-weeks and on the same diet supplemented with 15 mg of zinc for 9 weeks. The investigators assessed the subjects’ cardiovascular fitness using two types of stationary exercise bike tests and found a decline in fitness when zinc intake was low as compared to when it was supplemented. Blood tests confirmed that the low-zinc regimen decreased the body's stores of the mineral and lowered the activity of carbonic anhydrase enzymes, which depend on zinc. The researchers speculate that lowered levels of these enzymes, which help rid the blood of carbon dioxide, compromise the body's ability to dissipate the increases in carbon dioxide that exercise produces. These results suggest that adequate zinc intake is essential for maintaining exercise capacity.

(American Journal of Clinical Nutrition, May 2005)