Getting enough of five key minerals will supercharge your workout and strengthen your muscles, bones and heart. Here’s how to safely up your intake.
Getting enough of five key minerals will supercharge your workout and strengthen your muscles, bones and heart. Here’s how to safely up your intake.
Vitamins may be the nutritional superheroes everyone talks about, but minerals deserve an equal share of the spotlight. They play a key role in muscle strength and flexibility, bone density, and heart and lung health, research shows.
That makes them especially important for fit women who exercise regularly, says Liz Applegate, the director of sports nutrition at the University of California, Davis.
What’s more, studies report that activities like cardio and strength training can actually drain your stores of minerals.
“Zinc and magnesium are lost through sweat during exercise,” says dietitian Kim Larson, a spokeswoman for the Academy of Nutrition and Dietetics in the US. And endurance training may deplete calcium, according to a study in the Journal of the International Society of Sports Nutrition.
That’s a big problem, since most of us aren’t getting enough of these minerals to begin with. “Healthy, active women tend to focus on eating more fruits and vegetables and less meat,” Liz says.
While a produce-packed diet is indisputably healthy, meat is a top source of minerals like iron and zinc, she explains. As a result, women who avoid animal protein tend to fall short.
Fortunately, you can up your intake and get exactly what your body needs without going paleo. Use the smart strategies here to make these five minerals your priority.
Iron
It’s essential to help you power through your workouts. “When you exercise, your muscles take in oxygen from your bloodstream, and iron helps that process,” Kim explains. “If your iron stores are low, you’ll feel tired and lethargic.”
The longer and more intense your workout is, the more of the mineral your body requires. For instance, distance running may increase your iron needs by as much as 30 per cent, Kim says.
But finding the right balance is tricky: Too much iron can cause symptoms like joint pain and fatigue. Liz suggests that you aim for the recommended daily allowance of 18mg.
The typical diet supplies just 6mg of iron for every 1,000 calories consumed, so she advises eating iron-rich foods such as fortified cereal (look for one that contains no more than 9mg per serving), beef (85g has 2.9mg) and shellfish (one medium oyster has 4mg).
Vegetarians are especially vulnerable to iron deficiency because plants contain a type of iron, known as nonheme iron, that the body has trouble utilising.
If you’re not a meat eater, pair iron-packed legumes and dark leafy greens with vitamin C–rich foods such as broccoli and bell peppers, which help your system better absorb the mineral.
Calcium
This bone-building champ also regulates muscle contractions, which influences how hard and long you’re able to exercise, Kim says. Women who work out four to five times a week should get the recommended 1,000mg to 1,300mg a day, says Stella Volpe, a nutritionist and exercise physiologist at Drexel University.
Yet around 62 per cent of us are falling short, according to a study in The American Journal of Clinical Nutrition. “If you don’t take in enough calcium, your body will leech it from your bones, leaving you susceptible to fractures,” Stella says.
To get your fill, eat dairy products like yogurt (170g of the plain, low-fat type has 311mg) or fortified dairy substitutes (one cup of almond milk contains 450mg), kale (one cup, cooked, has 940mg) and sardines (one 100g can holds 351mg).
Magnesium
It helps your muscles use oxygen and glucose, making it critical for strength and endurance, Kim says. But the harder you work out, the more magnesium you lose. Research shows that during exercise, athletes sweat it out.
To keep your levels from dipping too low, you need 320mg a day. But women get just 274mg on average, a US Department of Agriculture survey found.
Bridge the gap with magnesium-rich whole foods like dark leafy greens (one cup of cooked spinach has 157mg), nuts and seeds (30g of almonds contains 77mg), and brown rice (one cup has 84mg).
Also smart: limiting yourself to no more than three cups of coffee and one alcoholic drink a day, Kim advises. Too much caffeine and alcohol depletes magnesium levels.
Zinc
You’ve heard that it can boost your immunity, but it’s important for muscle recovery, too. “Zinc works to repair tissues after exercise,” Kim explains. “It also helps your body metabolise carbs, fats and protein.”
Fit women need 9mg to 12mg of zinc a day, Liz says. The best sources are beef (85g contains 4mg), shellfish (85g of lobster has 3mg) and cheddar cheese (60g holds 2.6mg).
Zinc is also in chickpeas (one cup, cooked, has 1.7mg), quinoa (one cup, cooked, contains 2mg), and pumpkin seeds (a ¼ cup has 2.7 grams).
Potassium
This powerhouse helps every cell in your body use glucose for energy. Without enough potassium, your muscles get tired sooner, your reflexes are slower, and you may feel shaky or nauseated.
Trouble is, most women don’t even get half the recommended 4,700mg a day, according to Liz’s research. So it’s crucial to fill your diet with potassium-rich foods.
Despite what you’ve heard, bananas are not the best source. One medium banana contains just 422mg of the mineral. Better options include white beans (one cup, cooked, has 1,000mg), one medium baked russet potato (952mg), spinach (one cup, cooked, holds 839mg) and dried apricots (½ cup contains 755mg).
Maximise Your Mineral Intake
Choose Organic.
The farming practices that are used to grow supersize pest-resistant crops sap produce of minerals like calcium and iron, according to a landmark study in The Journal of the American College of Nutrition. Organic produce has more nutrients, says Dr Frank Lipman, the founder of the health company Be Well.
Spread the Goodness Around.
The body can absorb only so much of any mineral at a time. “When you try to get 100 per cent of the daily value in one meal, you actually take in less of it,” explains nutrition and fitness expert Liz Applegate. Eat no more than half of the recommended daily allowance in one sitting.
Don’t Fill Up on Fibre.
Get too much of it and you risk speeding minerals and other important nutrients through your digestive system before you have a chance to fully absorb them, Liz says. To prevent this, stick with about 25g of fibre a day, distributed evenly between your meals and snacks.
