Clinical Studies

For maximum muscle growth, it’s not just what you eat, but when you eat it, that makes all the difference.

You are serious about your exercise. No matter what level of athlete you consider yourself to be, when it comes to your workouts, the time and energy you invest into your body is valuable to you. As much as you focus on pushing yourself in the weight room or on the track, mat, or field, what you put into your body immediately before, during and after you exercise may be even more crucial to your results than the actual workout itself. Your pre-,intra-, and post-workout nutrition may be the limiting factor to your overall success and productivity.

Protein, protein, protein!

Our muscles are made of proteins. We already know that lifting heavy things can make your muscles grow – it’s the principle of adaptation. Lift something heavy, do it again and again, soon it will become less heavy. As your body adapts to the external stress of resistance exercise, it becomes stronger. Muscles are stimulated to grow, get bigger, “hypertrophy” and become stronger. Exercise does this by stimulating the body to make more muscle – a process called protein synthesis. But, intense exercise can also stimulate the catabolic processes of protein degradation.

The body tries to build and fortify muscle tissue to become stronger, to get ready for the next workout. But without additional protein being available to the muscle cells during the immediate post-training phase, the rate of muscle tissue breakdown can outweigh the rate of protein synthesis, or muscle growth and repair. Research has shown that muscle hypertrophy can only occur when the rate of protein synthesis (making of new proteins) exceeds the rate of protein breakdown consistently over time. It is impossible, then, to build muscle without the presence of sufficient protein to “feed” the body’s rebuilding efforts.

Recent studies have shown that ingestion of amino acids (molecular components of protein molecules)—specifically the amino acids leucine, isoleucine and valine (known as the branched-chain amino acids because of their structure)—directly support increased protein synthesis rates and improve net-protein balance. The BCAA’s, especially leucine, also play a stimulatory role in the secretion of the anabolic hormones, including insulin, growth hormone and IGF-1, and the direct stimulation of new muscle growth. “Thus, post-exercise amino acid ingestion represents an effective method to maximize the anabolic response to exercise.” (Koopman, et all, 2007)

Koopman also demonstrated that relatively higher doses of amino acids are necessary to support ongoing increased protein synthesis. Doses of 30-40 grams of amino acids immediately following exercise effectively stimulate protein synthesis. Lower doses also support muscle building, but for shorter periods of time.

What To Eat, When To Eat It

Research has shown that heavy resistance training is the most effective way to maximally stimulate muscle building and improve overall body composition. After each workout session, protein turnover rate is increased. This means, simply, that exercise stimulates the process of building muscle; but exercise also results in the increased rate of protein breakdown.

Protein intake is critical to the process of building and preserving lean tissue. And just as importantly—possibly more importantly—the timing of the ingestion of protein is critical to support the process. Protein ingested immediately after exercise has been shown to halt the catabolic processes that result from exercise. Adequate nutrition, specifically sufficient intake of protein in the phases immediately following exercise, will halt the catabolic processes induced by heavy resistance training, and will feed protein synthesis for new muscle growth. Although carbohydrate ingestion has been shown to have a protein-sparing, anti-catabolic effect post-exercise, the ingestion of sufficient protein, specifically the essential and branched-chain amino acids, is critical to promote gains in lean mass, muscle size and strength. And, ingesting your proteins around your workout, pre- and post-exercise, seems to have the greatest impact on both hypertrophy and muscular performance.

As we’ve already stated, research has shown that ingestion of protein as close to the workout as possible dramatically impact the net anabolic response of training. More recent studies have shown even greater anabolic response to resistance exercise when protein supplementation, specifically essential amino acids including the BCAAs were consumed immediately prior to training. Thus, taking protein as close to the conclusion of a training session, and also immediately before training, will most dramatically impact protein synthesis rates.

Pills, powders, or steak and eggs?

When measuring the impact of pre- and post exercise nutrition, we must consider absorption rate of the nutrients into the bloodstream and subsequently into the muscle cells. When it comes to the delivery of protein to the muscle cells for optimal anabolism, the most important factor to consider is the availability to the muscle cells – getting the muscle food to where it belongs, and getting it there when it’s most needed to feed recovery and growth.

We’ve stated that it is optimal to consume protein as close to your workout as possible, before and after training (some studies suggest ingesting BCAA’s intra-workout as well) for the best in muscle building and anti-catabolic effects. The essential and branched chain amino acids, especially leucine, have been shown to have the greatest impact on performance and protein synthesis, as compared to whole protein sources. This is because amino acids are available much more quickly to muscle cells than either protein powders or whole foods.

Essential Amino Acids/BCAAs: These “pre-digested pieces” of protein, are the most critical components to feed muscle growth. Research tells us that consuming essential amino acids, especially leucine, isoleucine and valine, prior to, during and immediately following strenuous exercise will have a positive effect on performance, enhance muscle growth and inhibit muscle breakdown.

Whey protein: milk-source protein, fast absorbing, high relative bioavailability. Use whey proteins within 1-3 hours on either side of workout, or first thing in the morning, for immediate anti-catabolic spike in circulating amino acids.

Casein: slower, sustained absorption into the bloodstream, casein is also a milk derivative. Both casein and whey support protein synthesis and muscle growth. Use casein any other time during the day, when real protein foods are not available. Casein forms a gel-like material in the gut, which gives it a slow, sustained absorptive characteristic. Relatively high bioavailability.

In conclusion, you got to lift big to get big, but you also got to eat big! You have got to eat lots of protein, and you need to get it into your bloodstream, and then into your muscle cells, fast. Avoid muscle breakdown, stimulate and enhance muscle growth, and feed your anabolic mechanisms, pre-during and post exercise, for to get the most out of your hard training sessions!

References:Antonio J, Timing and Composition of Protein/Amino Acid Supplementation. Strength and Cond. J, 2008; 30(1): 43-44 Hoffman JR. Protein Intake: Effect of Timing. Strength and Cond. J, 2007; 29(6): 26-34 Koopman R, Wagenmakers AJ, Manders RJ, et al. Combined ingestion of protein and free leucine with carbohydrate increases post-exercise muscle protein synthesis in vivo in male subjects. Am J Physiol Endocrinol Metab 2005; 288: E645-53 Koopman R, Saris WH, Wagenmakers A, Van Loon LJ. Nutritional Interventions to Promote Post-Exercise Muscle Protein Synthesis. Sports Med 2007; 37(10): 895-906 Phillips SM, Tipton KD, Aarsland A, et al. Mixed
muscle protein synthesis and breakdown after resistance exercise in humans. Am J Physiol 1997; 273: E99-107 Wiloughby DS, Stout JR, and Wilborn CD. Effects of resistance training and protein plus amino acid supplementation on muscle anabolism, mass and strength. Amino Acids 32: 467-477, 2006

– Reprinted with Permission

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