Aerobic exercise is part of a healthy lifestyle, and so is good nutrition. Eating right has a lot to do with the success of your aerobic activities, whether you are beginning to walk every day or are training for a marathon.
Good nutrition is eating the right amounts of the right foods. We need a balance of carbohydrates, proteins and fats. For people who enjoy aerobic activities, about half of the calories should come from carbohydrates, 20% from protein and 30% from fat.
Carbohydrates: Carbohydrates supply energy. We use some carbohydrate energy immediately, store some as glycogen in our muscles and liver and store the rest as fat. Glycogen reserves provide energy for about two hours of aerobic activity.
We need to eat the right kinds of carbohydrates. Carbs with a high glycemic index are metabolized rapidly and cause blood sugar and insulin levels to rise quickly. They are useful if you need a quick energy boost, but the boost won’t last long and often leaves you feeling more tired than ever within an hour or so. These foods—often made with processed sugars and grains—should be eaten sparingly and along with other foods that will sustain energy over a longer time.
Complex, low-glycemic carbs are the mainstay of an aerobic exerciser’s diet. These consist of whole grains, legumes, fruits and vegetables. In addition to healthy carbohydrates, they contain vitamins, minerals, phytochemicals and other micronutrients that are important for health.
If you exercise for long periods of time and/or at high intensity, you can deplete your glycogen stores. You hit the wall; suddenly you feel fatigued and can’t keep up your pace. You can prevent that by carb loading—eating more complex carbohydrates—for about 24 hours before working out. A high carb snack with some protein before your workout will help, too. Then eat an energy bar or have a carbohydrate-containing sports drink at least every two hours during training, and refuel afterward with another carbohydrate and protein-containing snack.
Protein: We use protein to build and repair muscle and other tissues. Growing people need lots of protein; adults need less. Lean meat, low-fat dairy products and high-protein vegetable sources (legumes and grains) are good protein sources.
Fat: Hear this: you need some fat in your diet. Fat is an essential nutrient, and our bodies use it for nervous tissue growth and repair. That means brains and nerves. Fat is an essential part of the membrane that surrounds every cell in your body and it controls the chemical reactions in those cells. Fat is also needed for our bodies to manufacture biochemicals like hormones.
The problem with Western diets is that we usually eat too much fat, and it’s the wrong type of fat. You need to get about a third of your calories from fat, but that doesn’t mean that a third of your food should be fat. Fat has more than twice as many calories as carbs and proteins do. A little goes a long way. Avoid saturated fat (fat from meat, lard, butter) and transfat, and make sure to get some monosaturated fat (olive oil, canola oil) and omega 3 fats (fish, flax seed, green vegetables).
Water: Water isn’t a nutrient, but you need it. Lots of it while you’re exercising. Drink at least 8 cups every day and more on the days you work out. Drink two glasses of water an hour before your workout and a glass every thirty minutes while you are exercising.
Good nutrition will give you the energy for aerobic exercise.