Are all dietary protein sources the same? What about supplements: whey vs. soy vs. casein?
Different types of proteins are comprised of differing amounts of essential amino acids (EAA) and have different rates of digestion. For example, whey is more rapidly absorbed than casein. Soy protein contains fewer EAAs than whey or casein. The EAA leucine is a key trigger for building muscle, so leucine-rich foods with rapid digestive properties are best for recovery from resistance exercise. Animal proteins—including plain or chocolate milk, lean beef and tuna—are leucine-rich. Plant proteins contain leucine, but in lower amounts.
Because casein is slowly absorbed, consuming casein-rich foods before bedtime—such as cottage cheese—can help support muscle-building processes throughout the night. This may be particularly important for athletes seeking to maximize muscular growth during building seasons, such as during a pre-season training program.
Do other nutrients consumed at the same time as protein affect muscle recovery?
Yes, you want to enjoy carbohydrates in combination with protein. Carbs are important to refuel muscles, while protein's job is to build and repair muscles. Adding some fat, such as low-fat or whole chocolate milk vs. fat-free chocolate milk, also seems to increase protein uptake. Researchers are unsure why fat enhances protein uptake, so stay tuned!
Does adding protein to a sports drink enhance performance and/or recovery?
Studies suggest no improvement in either endurance or speed (time trial performance). The benefits of having protein in a sports drink relate more to recovery. Protein contributes to slightly higher muscle protein synthesis and glycogen replenishment.
Should I eat protein before exercise to promote post-exercise recovery?
Won't hurt, but may not help. Eating 20 grams of protein 45 minutes before exercise increases amino acid uptake by the muscles to an equal extent as eating protein immediately after exercise. Take note: 20 grams of protein per recovery-dose is plenty. Athletes who consume higher amounts of protein either burn it for fuel or store it as fat.
More: Protein-Packed Smoothies
When athletes lose weight, they also lose muscle. Is there a way to prevent that loss?
About 25 to 30 percent of weight loss relates to muscle loss. To abate this loss of lean tissue, dieters have three options. They can create just a small calorie deficit—as opposed to starving themselves with a crash diet, choose protein-rich meals and snacks, or include resistance exercise twice weekly in their training.
How should vegetarians—particularly vegans—meet their protein needs?
Vegan athletes can successfully meet their protein needs by eating a variety of plant foods. Most grains contain all nine essential amino acids, just in lower amounts than an equivalent serving of animal foods. Hence, vegans need to consume generous portions of plant protein—grains, beans, legumes, nuts, soy—to compensate for both the lower density of the protein as well as the fact that plant proteins are less bioavailable due to their fiber content.
The wisest way for a vegetarian to optimize protein intake is to consume adequate food. If the vegan is undereating, an energy deficit easily leads to muscle loss. Vegans who want to lose fat and not muscle will want to focus their limited food intake on protein-rich plant foods.
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