When it comes to choosing foods that will improve your exercise performance, there are a few musts. First, always eat a healthy breakfast. This is important every day, of course, but it’s essential on the days that exercise is on your agenda. Skipping breakfast can make you feel light-headed or lethargic while you’re working out.

Start your day with complex carbohydrates and protein.

Too many people rely on simple carbohydrates to start the day. But a bagel or a bowl of cereal won’t keep you feeling full for very long. Try oatmeal, oat bran, or any hot or cold cereal that is high in fiber (at least five grams of fiber per serving), and then throw in some protein, such as an egg, some milk, or yogurt. If you’re making pancakes or waffles, put some cottage cheese in the batter, and then slather peanut or almond butter on top of the finished product.

Carbohydrates have gotten a bad rap thanks to the last decade’s fad diets, but they are actually the body’s main source of energy. It’s just that in our culture, we rely too much on the simple carbohydrates that are found in sweet and processed foods rather than on the complex ones found in whole grains, fruits, vegetables, and beans. It’s the complex carbs that make you feel comfortably full for longer. Whole grains, including whole wheat bread and whole grain pasta, have staying power because you digest them more slowly than the refined grains. They also keep blood sugar levels stabilized.  The bottom line is that about 70 percent of your total daily calories should come from carbohydrates, ideally of the complex variety.

Protein helps replace certain cells in our body that are programmed to die out after a certain amount of time. For example, red blood cells die out after about 120 days, and must be replaced. Protein also helps regulate some essential body processes, such as keeping blood vessels open, and protein supplies energy when carbohydrates are in short supply. Adults need to eat about five ounces of protein a day — and it can come from poultry, meat, fish, dairy, legumes, and even peanut butter.

Boost your fruit and vegetable intake.

When it comes to fruits and vegetables, the recommended “five a day” should be the minimum. Aim to eat afruits and veggies from every color of the rainbow every day. Fruits and vegetables provide fiber, antioxidants, and electrolytes, which are essential to your body. Every time you go to the grocery store, try to choose at least one fruit or vegetable that you don’t eat on a regular basis. For snacks, keep dried fruits at your desk or in your workout bag.

Eat these before exercise.

When it comes to fueling up before a workout, low-fat foods rule. They make you feel more energized than foods made with simple sugars, and greasy food is an exerciser’s worst enemy. Some great pre-workout energy foods include:

Bananas

Bananas are full of potassium and magnesium, minerals you need to replenish when you’re sweating hard.

Berries, grapes, and oranges

These are all full of vitamins and minerals, are easy on the intestines, and give you a quick boost.

Nuts

Nuts are a great source of protein (and essential nutrients), and they will give you sustained energy. 

“Nut” butter

Most grocery stores carry single-serving packets of peanut butter that don’t need to be refrigerated and are easy to keep in your gym bag. You can slather nut butter on an apple, crackers, or a slice of whole-grain bread.  If you don’t like peanut butter, try almond or soy butter.