You eat lots of produce and lean protein, so you’re probably all set with vitamins and minerals, right? If you’re hitting the gym on a regular basis, that may not be the case. Certain nutrients are vital for your muscles to work efficiently, and, “moderate to vigorous exercise increases the loss of some minerals, mostly through sweat,” says Kelly L. Pritchett, R.D., spokesperson for the Academy of Nutrition and Dietetics. Translation: Being active could mean your stores are totally tapped out. Read on to learn which of these essentials you might be missing and how to up your intake to help you perform at your peak.
1. Vitamin B
Lacking the energy to push out those last few reps? Chances are you’re low on this group of micronutrients, which includes vitamins B6 and B12, thiamin, riboflavin and folate. The body uses these to convert protein and sugar into energy and to produce red blood cells. Athletes with low levels performed worse during high-intensity exercise, according to research published in the International Journal of Sport Nutrition and Exercise Metabolism.
Get more from: Tuna, black beans, lentils, peanuts
2. Calcium
Milk does a body good — the commercials didn’t lie. Each additional cup of skim milk consumed per day reduced runners’ incidence of developing a stress fracture by 62 percent, according to a study from the American Academy of Physical Medicine and Rehabilitation. The calcium, along with vitamin D, potassium and protein in the dairy drink significantly increased participants’ bone density — and a strong skeleton is key for any high-impact activity.
Get more from: Milk, yogurt, leafy greens, beans, fortified cereals
3. Vitamin C
Up to half of people who work out in chilly conditions suffer from some degree of exercise-induced asthma. Good news: The citrus that’s in season all winter, like oranges and grapefruit, might help. Vitamin C can reduce coughing, wheezing and shortness of breathe during and after exercise, according to recent research from the University of Helsinki in Finland. It also significantly decreases the likelihood of active people coming down with the common cold.
Get more from: Oranges, strawberries, bell peppers, kale
4. Vitamin D
Soaking up some sun doesn’t just boost your mood — it can pump up your power, too. In a new study from Newcastle University in England, patients reported less fatigue after receiving a dose of vitamin D. Why? Without enough of this nutrient, the mitochondria in muscle fibers can’t adequately regenerate energy after your muscles contract, making you feel tired more quickly.
Get more from: Milk, salmon, trout, egg yolks
5. Vitamin E
If you’re a gym devotee, you can slash the chance of becoming sick by consuming some of this oily antioxidant. Taking the vitamin lowered risk of pneumonia by 69 percent among nonsmokers who exercise, according to a study published in the journal Clinical Epidemiology.
Get more from: Sunflower seeds, almonds, peanut butter
6. Iron
To help your muscles work efficiently, you need to pump some iron — literally! An hour of working out could deplete 5.7 percent of your level of this mineral, which helps red blood cells carry oxygen to muscles. Losing too much of your stores can result in iron-deficiency anemia, which causes fatigue and zaps your endurance during lengthy sessions.
Get more from: Beef, eggs, spinach, broccoli, fortified cereals
7. Magnesium
This mineral is a powerhouse for weekend warriors to pro endurance athletes alike. “Magnesium is a component of more than 300 enzymes involved in energy metabolism, plus it plays a role in bone formation,” says Pritchett. Improved bone density is important for protect yourself from stress fractures during high-impact activities. You lose magnesium through sweat, so munch on some good sources of it before a hard weight-training session or long run.
Get more from: Leafy greens, almonds, halibut, quinoa
8. Potassium
There’s a reason marathoners grab a banana after crossing the finish line: Its high potassium content helps nix cramps and speed up recovery. How? The mineral works with sodium to help your muscles and nerves work properly. Plus, says Pritchett, “It’s the primary electrolyte in intracellular fluid, meaning it plays a big role in balancing water content throughout the body.” Consider it essential fuel following a tough workout or a strenuous outing lasting more than an hour.
Get more from: Sweet potatoes, bananas, avocados, tuna
9. Sodium
It seems like “sodium” is a swear word in the health-o-sphere — and with its prominence in processed and take-out food, it’s true many people need to cut back. But if you’re into endurance events, by sweating out sodium and hydrating with water alone, you could experience heat cramps or hyponatremia, a low concentration of sodium in the blood that can be fatal in extreme cases. “Salty sweaters (who notice a white film on their skin after a workout), heavy sweaters (who produce a high volume of sweat during exercise), people working out in hot, humid temperatures, and endurance athletes need to pay close attention to their sodium intake,” advises Pritchett. For long or grueling sessions, stash some salt packets in a pocket or FuelBelt and eat them mid-workout.
Get more form: Gatorade, pretzels, salted nuts
10. Zinc
Loading up on carbs while limiting protein and fat causes deficient levels of zinc in up to 90 percent of athletes. This can zap your energy and endurance. Likewise, recent research from the United States Department of Agriculture found that limiting zinc intake lessened cyclists’ oxygen uptake — leading them to fatigue more quickly. Make sure you have enough of the mineral for a challenging session by ordering a side of meatballs during your pre-race pasta dinner.
Get more from: Red meat, chickpeas, pumpkin seeds, quinoa
Going overboard with some nutrients can be as detrimental as skimping on them, so talk with your doctor before changing your diet or reaching for any supplements. Figure out the right balance for you — then go out and set a new personal best.