As much as exercise hits your body with a barrage of feel-good hormones, it also puts your body in a state of stress. From your gut to your heart, every cell is working hard to maintain all bodily functions while you work out. That’s why it’s so important to get proper nutrition and fuel your body with foods rich in vitamins and antioxidants. “Exercise produces stress on the body, and that increases the need for certain nutrients that the body might otherwise be able to produce enough of,” says Ashley Koff, RD, founder of The Better Nutrition Program and Espira by AVON nutritionist.
Take the amino acid, glutamine, for example. “Your body produces it, but when your body is under stress during exercise, you need more of it to repair muscle, including the digestive tract lining,” Koff says. Read on to learn what vitamins, macronutrients and amino acids are crucial for building and maintaining muscle.
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You already know how important it is to drink enough H2O for replenishing fluids before, during and after a workout. But staying properly hydrated also aids digestion and nutrient absorption. “Hydration is more than just quenching thirst; it means water carries nutrients to the muscles for them to do their work,” Koff says.
Best sources: Straight from the tap, or vegetables and fruits
Protein is one of the most essential macronutrients for muscle growth and repair because it’s packed with amino acids that your body does and doesn’t produce. That’s why it’s important to have protein post-workout to restore these muscle-building macronutrients. “Proteins not only helps rebuild and build lean body mass, but they’re also a core part of enzymes and hormones that help communicate with the body to repair itself,” Koff says.
Best sources: Dairy, lean meats, beans and other legumes, seafood, soy and eggs
Calcium does more than help build strong bones and prevent osteoporosis. Koff says the mineral is responsible for triggering muscle contraction. Muscles are comprised of two protein filaments: myosin and actin. When muscle contraction occurs, these filaments slide over each other to convert ATP (adenosine triphosphate), aka the way your body stores and uses energy. The more you exercise, the more ATP your body needs to keep your muscles moving.
Best sources: Yogurt, fortified milk and cereals, cheese, tofu and spinach
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Feeling more tired than usual? A magnesium deficiency could be to blame. As one of the best de-stressing minerals, magnesium is essential for muscle relaxation and preventing cramps, Koff says. Together with calcium, magnesium works to help reduce blood pressure and promote better sleep.
Best sources: Leafy greens, beans and other legumes, squash, nuts and seeds and whole grains
You might have heard of non-essential (meaning your body can produce it) and essential (meaning your body can’t produce it) amino acids, but there are also conditionally essential amino acids. Koff says your body needs more conditionally essential amino acids, such as glutamine, during intense workouts. “Glutamine helps repair muscle tissue, including the lining of the digestive tract, especially when the body has experienced stress during high-intensity exercise, like weightlifting and HIIT,” Koff says. Glutamine is also important for maintaining gut function and boosting the immune system.
Best sources: Chicken, fish, beef, dairy, eggs and spinach, Brussel sprouts and fermented foods
6. Vitamin D
The sunshine vitamin is probably best known for ensuring strong bones, but it’s also critical for strong glutes, biceps and everything in between. Koff says, “Vitamin D is linked to healthy hormones like testosterone, which helps with muscle maintenance and growth.” A daily dose of D can also improve your mental health and help reduce anxiety. Because not that many foods are rich in vitamin D, some doctors and nutritionists recommend taking a supplement.
Best sources: Fatty fish, like salmon and sardines, fortified yogurt, milk and orange juice, mushrooms and eggs
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Just like calcium and magnesium, potassium is a key electrolyte in muscle contraction. But it’s also essential for carrying other nutrients to your muscles. “Potassium brings water, along with other nutrients, into muscle cells. They work in opposition to sodium,” Koff says. Potassium helps your kidneys flush out the excess sodium in your body, Koff explains. What’s more: New studies have shown that people who don’t get enough potassium are at higher risk for hypertension and heart disease.
Best sources: Bananas, squash, sweet potatoes, broccoli, chicken and salmon.
Contrary to what you might believe, carbs are one of the best building blocks of muscles. “They’re the key nutrient to support muscle growth and repair,” Koff says. As the best source of glycogen, carbs help fuel your workouts and rebuild muscles more effectively post-workout. Runners aren’t the only ones who can benefit from carb loading. Everyone from weightlifters to HIIT enthusiasts need to restore glycogen stores after an intense sweat session.
Best sources: Whole grains, vegetables, fruits and beans and other legumes
Vitamin B12 (cobalamin) belongs to a set of eight B vitamins known as the vitamin B complex. But what sets B12 apart is it assists in creating red blood cells, which contain hemoglobin that binds to oxygen. “[Iron] builds red blood cells, which carry oxygen to muscle, and helps metabolize protein and fats for use in muscle building and repair,” Koff says.
Best sources: Poultry, meat, fish and dairy
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If you want to know why Popeye was slamming down cans of spinach, it’s because the leafy green is packed with iron, a mineral that “brings oxygen to muscle tissue,” Koff says. It also helps regulate metabolism and promotes a healthy immune system. Without enough iron, your red blood cells can’t carry oxygen to your muscles and the tissues that need it.
Best sources: Leafy greens, lean beef, poultry, fish, eggs and fortified whole grains
Muscle cramps are one of the most common sleep complaints. The good news: Beta-alanine, a non-essential amino acid, has been shown to help people stave off muscle cramps from doing intense workouts, says Koff. “Beta-alanine helps produce carnosine, which balances the pH in muscles and fights against lactic acid buildup that leads to fatigue and cramping,” she says. Koff also says that vitamins C and E can help combat inflammation from excessive exercise. “Vitamin C helps with muscle repair as it supports collagen production, and vitamin E helps remove free radicals produced after a workout,” Koff adds.
Best sources: Animal protein and plant-based foods, like asparagus, edamame, seaweed, turnip greens and watercress
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