Fitness fuel: What to eat, when to eat

If you're starting a new exercise routine this new year, you probably want to know what to eat — and when to eat it — to support your new fitness goals.

There is plenty of information about eating before or after workouts, and several schools of thought about loading up on carbs versus proteins. What works and what doesn't? Here are a few tips to keep in mind about eating to fuel your exercise regimen.

Watch your portion

Loading up on a big meal before you work out is a huge no-no because it can make you feel lethargic — and even cause stomach cramps or diarrhea. But if you don't eat enough, you won't have enough energy to enjoy and optimize your exercise time.

The Mayo Clinic offers the following guidelines:

• Large meals. Eat least three to four hours before exercising.
• Small meals. Eat two to three hours before exercising.
• Small snacks. Eat an hour before exercising.

Eat after you exercise

The Mayo Clinic also recommends eating a meal that includes protein and carbs within two hours after an exercise session. If you aren't hungry right after, try a sports drink or juice to replenish carbohydrates lost during the workout. Try foods such as yogurt, fruit, peanut butter, string cheese, crackers, nuts or a regular, well-balanced meal.

Protein helps muscles recover and grow, and the best time to give your body much-needed protein is right after exercise. It doesn't have to be from a protein shake, either. Have a hard-boiled egg, glass of milk or a whey protein shake. But remember that more isn't better — you only need 10 to 20 grams of protein to deliver the amino acids necessary to build and recover muscle, according to sports dietitian Christine Rosenbloom, PhD, RD, CSSD.

Avoid certain foods before exercise

While a salad may be a healthy meal, having one before you work out isn't a good idea because it is harder to digest and likely does not provide sufficient carbs to deliver energy. Also, pay attention to your body -- if certain foods cause digestive discomfort, avoid them as pre-workout meals.

Pay attention to timing

Obviously, if you work out in the morning, you may not have time to digest a full meal, so stick to lighter fare. Good pre-workout foods include apples, almonds, turkey, grapes, berries or a whey protein shake. If you work out later, you can do it after a larger meal, or have a lighter snack and eat after. Forget about trying to work out at the "best time" of the day, experts say. Just get the activity in when you can and plan your food around it.

Be aware of the activity

If you are practicing yoga that's less rigorous than, say, spinning, you may need less fuel. You also want to pick something that digests quickly, because hanging upside down will not help food go down more quickly.

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