by Jeff S. Volek, Ph.D., R.D.
We all know that protein is an integral part of a healthy diet, and absolutely necessary for physically active individuals. But not all proteins are created equal.
Highest Quality Protein
protein is a very high quality protein which, along with casein, makes up the major proteins in milk. Whey contains all the essential amino acids and therefore scores very high on all methods used to score protein quality. In fact, whey protein is superior to all other sources of protein when you consider how much of the nitrogen (protein is about 16% nitrogen) is retained in the body relative to the amount of nitrogen absorbed. This criterion method of protein quality is referred to as the biological value (BV), and whey protein has the highest score of 100.
A growing body of literature shows that appropriate use of whey protein can maximize muscle size and strength gains from resistance training in addition to having other health-promoting effects. 3 Studies Show Whey Builds Muscle Better
A recent study compared whey versus casein protein supplementation on strength gains and body composition in subjects engaged in a 10-week resistance training program. Results showed superior gains in lean body mass and strength in the whey group. In a follow-up study, the same investigators divided bodybuilders into four groups: a whey protein group, a whey protein plus creatine group, a carbohydrate supplementation group, or a carbohydrate supplementation plus creatine group. All subjects were engaged in resistance training. Body composition and muscle fiber size were determined. Subjects in the whey protein group demonstrated greater gains in strength, lean body mass, and type II muscle fiber area than the carbohydrate only group. The addition of creatine to the whey resulted in even more dramatic increases in strength, lean body mass, and cross-sectional area of muscle fibers.
In another study, men who supplemented with whey protein had greater increases in lean body mass compared to a placebo group after 6 weeks of resistance training.
These studies provide strong evidence that whey protein can have a major influence on muscle size and strength gains with resistance training in a relatively short period of time. Whey Prevents Damage Caused by Overtraining
Whey protein contains beta-lactoglobulin, a rich source of branched-chain amino acids (BCAAs). Our laboratory recently examined the effect of an amino acid supplement (rich in BCAAs) on muscular strength during short-term resistance overtraining (each muscle group trained 5 days per week). As we expected, maximal squat and bench press strength significantly decreased in the placebo group after one week of overtraining (-5.2% and -3.4%, respectively) whereas the performance by those who supplemented with amino acids was unchanged (-0.4% and -1.2%, respectively), indicating that providing additional essential amino acids, in particular BCAAs, can prevent the acute stress response associated with short-term overtraining. Whey May Keep Your Immune System Happy
Whey proteins have other health-promoting benefits as well. Whey is a rich source of cysteine, the rate-limiting amino acid for synthesis of the antioxidant glutathione. Whey protein can increase glutathione levels and protect against oxidative damage. There is also research showing whey protein can be useful for patients with cancer and high blood pressure. Recent evidence indicates whey is also effective at increasing antibody responses, which help fight off antigens. Thus, whey supports your immune system. How Whey Helps Low-Carb Dieters
Whey proteins are ideal for use with low-carbohydrate weight loss diets. Because whey is a high-quality protein with a high biological value, you can maintain nitrogen balance and lean body mass and lose more fat while consuming fewer calories if whey protein is consumed. The extra BCAAs in whey are also beneficial during low-carbohydrate diets because they can be oxidized (burned) as an energy source when carbohydrate availability is low. The Best Time of Day to Consume Whey to Maximize Muscle Building
Timing of protein intake is essential to maximize the anabolic response to resistance exercise. In particular, a protein source that contains all the essential amino acids and one that is rapidly absorbed is needed in order to take advantage of the critical window around a workout for muscle growth. Whey protein is ideal for this purpose. Protein synthesis was stimulated about 400% above pre-exercise values when a protein supplement containing all the essential amino acids was consumed 1 or 3 hours after a bout of resistance exercise. Consumption of this same protein supplement immediately before exercise resulted in greater net muscle protein synthesis compared to consumption of the supplement at various times after exercise. Thus, the timing of supplement ingestion (i.e., immediately before exercise) is critical to maximize the anabolic response. These same investigators reported that the acute anabolic response to 15 grams of essential amino acids (the amount found in about 30 grams of whey protein) provided before and immediately after resistance exercise is additive and indeed reflects the 24 hour response. In other words, protein supplementation before and after resistance exercise improves protein balance when measured over an entire day.
Further emphasizing the importance of timing, a recent study reported that early intake of a protein-carbohydrate supplement after a workout is more effective at increasing skeletal muscle size and lean body mass than a supplement consumed several hours later.
To recap, I would recommend supplementing with protein both before and immediately following a workout in order to reap the maximum benefit to your muscles. A fast-absorbing protein source with ideal ratios of essential amino acids, like whey protein, is necessary to maximize this anabolic effect. Who Should Take Whey Protein?
Whey protein is an excellent, high-quality protein source with advantages over other proteins. Research shows whey may support greater increases in lean body mass and decreases in body fat as part of a resistance training program. Certain constituents of whey may also promote antioxidant status and a healthy immune system. Since exercise, in particular excessive exercise, can result in compromised antioxidant and immune status, whey might be particularly effective in individuals who exercise intensely on a regular basis. Whey also offers benefits for individuals of all ages just wanting to maintain or enhance health even if one is not very physically active.