Proteins are molecules that consist of one or more chains of amino acids. They are a structural component of muscle and other tissues in the body .
Whether you are a competitive weightlifter, bodybuilder or you just want to look your best, you would surely benefit by knowing the ideal nutritional intake protocol needed to maximize muscle hypertrophy and strength. Type, timing and amount of protein intake are essential to meet strength-training goals. Clinical trials are showing that taking protein (especially whey) in combination with strength training improves athletic performance, increases lean body mass, strength, and muscle size [1-8].
How Much Protein Should You Take?
Number of investigations involving strength and endurance athletes have shown that exercise increases the protein and amino acid need . For endurance athletes, exercise can increase the need for protein by 50 to 100%. The need for protein in strength athletes is less clear, however, protein intake in excess may promote muscle developement . Many studies are showing that for maximal muscle hypertrophy to occur, bodybuilders need to ingest from 1.2 to 2.0 grams of protein per kilogram of body weight daily.[1-3] The recommended dietary allowance (RDA) for protein is 0.8 grams per kilogram of body weight which meets the needs of majority of all healthy adults not involved in weightlifting.
Which Protein Source is the Best?
So, the evidence is clear that athletes do benefit from increased protein intake. The focus then becomes on what type of protein to take. There are numerous protein sources available to the consumer. However, there are three sources of dairy protein (bovine milk, casein and whey) typically used in studies of muscle hypertrophy and strength. Quality of protein is often measured in biological value which indicates how efficiently the body makes use of them. Biological value measures protein quality by calculating the nitrogen used for tissue formation divided by the nitrogen absorbed from food . Some protein biological value rankings: Whey – 104, Bovine milk – 91, Casein – 77, Soy protein – 74.
Pic. 1 – Scoop of a protein powder.
Whey has the highest biological value, thus being superior to both milk and casein. Whey is the liquid part of milk that remains following the process of cheese manufacturing . Whey proteins are than separated and purified . There are three main techniques to purify whey protein and each yield s a different whey form (whey powder, whey concentrate, and whey isolate). Compared to whey isolates whey concentrate actually contains more biologically active components . Whey Protein Isolate is the purest source of protein (90% or higher) . Although isolate is the purest form, the manufacturing process often breaks down their structure and loses peptide bonds which reduces the effectiveness of the protein .
Casein forms a gel or cloth in the stomach which results in sustained release of amino acids. Like whey, casein is a complete protein, meaning they both contain a complete set of essential amino acids (EAA) [5,6]. Casein also contains the minerals calcium and phosphorous. Compared to whey, the plasma appearance of dietary amino acids after casein ingestion is slow, lower, and prolonged .
What is the Best Timing for Protein Ingestion?
That is one of the most frequently asked questions and studies are showing that timing is very important factor when it comes to protein ingestion especially in relation to exercise. Cribb et al.  assigned 23 male bodybuilders into two groups for a 10-week resistance weight-training. One group received supplement (40 g whey protein, 46 g glucose and 7 g creatine) before and after a workout, while other in the morning and evening. There were significant differences in body composition in the before and after a workout supplemented group. This group also experienced increased lean body mass and decreased body fat and significantly greater gains compared to “morning and evening” group.
Hoffman et al.  supplemented with protein only. The study concluded, after 10 weeks of training, that supplementation pre/post each workout resulted in greater improvements in 1RM strength and body composition compared to group who consumed supplement in the morning and evening.
One study also showed that adding protein to your breakfast along with a high fiber grain keeps you full for longer which can help you eat less throughout the day and aid you in meeting your weight loss goals .
Side Effects and Concerns
One of the major concerns about protein consumption is associated with renal (kidney) function. Proteins are said to cause renal damage to healthy humans. In healthy population there does not appear to be any adverse effects of a high protein diet. Poortmans et al. concluded that protein intake under 2.8 g/kg does not impair renal function in well-trained athletes . If an individual has an existing kidney disease protein intake should be limited to to approximately half of the normal RDA level for daily protein intake (0.8 grams per kilogram).
Lemon, P. W., and D. N. Proctor. “Protein intake and athletic performance.” Sports Med 12.5 (1991): 313-325.
Phillips, Stuart M. “Protein requirements and supplementation in strength sports.” Nutrition 20.7 (2004): 689-695.
Lemon, Peter WR. “Beyond the zone: protein needs of active individuals.” Journal of the American College of Nutrition 19.suppl 5 (2000): 513S-521S.
Gropper, Sareen S., and Jack L. Smith. Advanced nutrition and human metabolism. Wadsworth Publishing Company, 2012.
Hoffman, Jay R., and Michael J. Falvo. “Protein-Which is best.” Journal of Sports Science and Medicine 3.3 (2004): 118-30.
Boirie, Yves, et al. “Slow and fast dietary proteins differently modulate postprandial protein accretion.” Proceedings of the National Academy of Sciences 94.26 (1997): 14930-14935.
Cribb, Paul J., and Alan Hayes. “Effects of Supplement-Timing and Resistance Exercise on Skeletal Muscle Hypertrophy.” Medicine & Science in Sports & Exercise 38.11 (2006): 1918-1925.
- Hoffman, Jay R., et al. “Effect of a proprietary protein supplement on recovery indices following resistance exercise in strength/power athletes.” Amino acids 38.3 (2010): 771-778.
- Michael W. Smith, MD. Retrieved from WebMD.com at 24. May 2013
Poortmans, Jacques R., and Olivier Dellalieux. “Do regular high protein diets have potential health risks on kidney function in athletes?.” International Journal of Sport Nutrition 10.1 (2000): 28-38.