Physically active women who took a monthly supplement containing essential minerals sliced nearly a minute off a three-mile run – and gained other aerobic benefits, according to a study appearing in the Journal of the International Society for Sports Medicine.
The supplements, developed by a team of researchers led by Dr. Robert DiSilvestro at Ohio State University, included five key micronutrients, including iron, copper and zinc, that are often found in low levels among women.
“We know that young women, in particular, often have micro-deficiencies in nutrients and that those nutrients play a role in how cells work during exercise,” said DiSilvestro, a professor of human nutrition at Ohio State and the lead author of the study.
The first portion of the study assessed how 28 women performed on three activities measuring aerobic output – a three-mile run, a 25-minute ride on a stationary bike, and a step challenge that counted how quickly a person could step up and down from a bench.
Women who took the supplement for a month prior to the tests reduced their three-mile time from an average of 26-and-a-half minutes to just over 25-and-a-half minutes. Women who took the supplement also increased their mileage during the 25-minute bike ride from six miles to about six-and-a-half miles. The women taking the supplement saw improved results on the step test, as well.
No similar effect was seen among the 14 women who were given a placebo, in this case a supplement containing no micronutrients.
Why Women Can Benefit
In addition to the iron, copper and zinc, the supplements also contained two other important nutrients – carnitine and phosphatidylserine, which are a combination of amino acids and fatty acids.
“I decided to start with minerals that are commonly low – or thought to be low in many diets – and brought in some of the supporting cast. These two [amino acid] nutrients, which are needed for cell function, are made by our bodies but also come from food we eat,” DiSilvestro said.
Due to lifestyle and other factors, these types of micronutrients, which have previously been tied to aerobic and cardiovascular performance, tend to reside in low levels among women, according to the researchers.
“[Women] tend to eat less meat than men, and menstruation also plays an important role in mineral loss,” noted DiSilvestro.
The researchers recruited groups of women between the ages of 18 and 30 who were already physically active and had a history of running. With their exercise history, the women were less likely to receive a boost in performance from simply working out more than usual, noted the researchers.
A follow-up study to the initial performance assessment involved an additional 36 women. Taking the same supplements, the women in the second portion of the study slashed their three-mile run times by an average of 41 seconds. That confirmed to researchers that their micronutrient elixir was producing real results.
Based on the promising results, DiSilvestro is working to develop the supplement as an over-the-counter product, which he believes can help improve aerobic performance.
“The run-time drops in people at this stage of life were pretty large when they took the supplement. And in the placebo group, we saw little change,” DiSilvestro said.