
Too Little Magnesium Makes One Work Harder
By Judy
McBride April 7, 1997Older people whose heart rate soars and
energy dives during aerobic exercise may want to take a closer look at their
magnesium intake, according to new Agricultural Research Service findings. In a study, a group of post-menopausal women experienced a significant drop
in their work efficiency when their magnesium intake was reduced to a little
more than half of the Recommended Dietary Allowance for three months. That
occurred even though blood magnesium levels showed no sign of deficiency, the
study leader reports today at the Experimental Biology 97 meeting in New
Orleans. The study is the first to look at the effect of low magnesium intakes on the
physiological function of people over age 55. According to the latest
USDA nationwide food consumption survey,
fewer than one-third of people over age 50 consume the recommended amount of
magnesium through their diet. During the study, the low-magnesium diet affected the womens
physiological function in three ways as they cycled on an ergometer. First,
they spent 10 to 15 percent more energy, as indicated by a rise in oxygen
consumption, compared to when they were getting ample magnesium. Second, their
heart rate increased about 10 beats a minute. And third, the amount of
magnesium stored in their muscle tissue dropped measurably. Watching your diet takes on new meaning with these findings. But its
easy to get ample magnesium in a low-fat diet, the scientist said. Eat more
vegetables, especially dark leafy greens; more whole wheat and other whole
grain breads, cereals and pastas; and more dried beans. Scientific contact: Henry C.
Lukaski, ARS Grand Forks Human
Nutrition Research Center, Grand Forks, N. D., phone (701) 795-8353,
[email protected]. U.S. Department of Agriculture | |