Some specialists say that young women are more prone than men to nutritional deficiencies, which can impact their energy levels and keep them from fulfilling their athletic potential. A study claims to have found the right supplement mix to address that issue.
Much research lately has been dedicated to showing how changing our dietary habits and doing regular aerobic exercise — such as running or biking — can improve our physical and mental health.
Still, some nutritionists say that, despite efforts to lead healthier lifestyles, women's energy metabolism, in particular — their ability to produce energy out of the nutrients they consume — may be impaired, and through no fault of their own.
Robert DiSilvestro — a nutritionist and researcher at the Ohio State University in Columbus, OH — in collaboration with other researchers, may now have pinpointed the supplementary "shake" of minerals and essential nutrients that could give women the daily energy boost they need.
"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. They tend to eat less meat than men, and menstruation also plays an important role in mineral loss."
The recipe for success that the researchers tested consists of three minerals — iron, zinc, and copper — and two essential nutrients — carnitine and phosphatidylserine — which, they say, women tend not to absorb enough of.
Their results were published in the Journal of the International Society of Sports Nutrition.
The mix that makes us faster runners
DiSilvestro and team conducted two consecutive experiments, over a period of 1 month each. The participants' athletic performance was, in each case, measured once at the start, and once at the end of the study period.
For the first experiment, the researchers recruited 28 female participants aged between 18 and 30; half of these were assigned to take the supplement, while the other half were given a placebo and acted as the control group.
The women who were given the supplement would take it by stirring it twice daily into a drink of their choice. "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," explains DiSilvestro.
"These two nutrients [carnitine and phosphatidylserine], which are needed for cell function, are made by our bodies but also come from food we eat," he notes.
As part of the experiment, the women were asked to engage in a range of aerobic activities: first a 3-mile run, then stationary biking for 25 minutes, and, finally, a test involving stepping on and off a bench.
While all the women were amateur athletes and regularly engaged in running, they did not normally perform the other two exercises they were asked to do during the study.
The researchers explain that this requirement was added on purpose, to understand whether the energy benefits potentially derived from the supplement would extend to a wider rage of physical activities, beyond just running.
Following this first experiment, DiSilvestro and team found that the 14 women who drank their nutritionally packed "shake" ran significantly faster than before, and also compared with their counterparts in the control group. They covered the 3 miles in 25.6 minutes on average, compared with their previous performance of 26.5 minutes on average.
Their performance was also improved in the other two types of exercises. In 25 minutes on the stationary bike, the supplement-takers increased their calculated distance from an average of 6 miles — measured at the beginning of the experiment — to 6.5 miles per average.
They also increased the number of steps in the step test to about 44 from approximately 40 steps in 90 seconds.
Dosage is important
In the follow-up experiment, the researchers were interested in seeing if they could reproduce this effect with a slightly modified version of their dietary supplement, which contained a lower dose of carnitine.
This time, the researchers recruited a new group of women — 36 in total — who were split in the same way and asked to engage in the same exercises. Also, the nutritional supplement was administered in capsule form on this occasion.
In this experiment, the researchers noted a mean decrease of 41 seconds in running time.
These differences are particularly interesting to DiSilvestro, who aims to eventually produce a reliable supplement that could help women to correct their nutritional deficiencies and thus improve their athletic performance.
The researchers note that the dosage of each of the nutrients used in all versions of the supplement were well below dangerous levels, capable of causing undesirable side effects. They also add that, indeed, no side effects were observed at any stage.
DiSilvestro claims that men do not usually experience the same nutritional deficiencies noted in women, but he says that future studies might focus on testing the benefits of such a supplement in the case of vegetarian men, or as an energy-booster for long-distance runners.