Definition: "An ergogenic aid is any substance or phenomenon that enhances performance "

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Pre-digested protein during workout stimulates muscle growth

Consuming small quantities of protein during a weight workout increases the protein production in your muscles, write researchers from the University of Maastricht, the Netherlands, in the American Journal of Physiology.

The researchers got ten young test subjects to do a whole body weight-workout. During the training session the athletes were given something to drink every 15 minutes.

The composition of the drink varied. On one occasion the athletes were given 0.15 g sugars per kg bodyweight per hour. [CHO] Half of this consisted of glucose sugars, and the other half maltodextrin.

On the other occasion the athletes were given proteins in addition. [CHO+PRO] The subjects were given 0.15 g PeptoPro per kg bodyweight per hour on top of the sugars. PeptoPro is a hydrolysed protein that the body absorbs ultra fast.

What’s interesting about the Dutch study is that the test subjects trained at the end of the day, so they had already eaten. Their meals were composed of 60 percent carbohydrates, 14 percent protein and 26 percent fat. In studies like this the researchers usually get their subjects to train on an empty stomach. As a result, most studies on the effects of protein before or after training say little about real-life situations.

The researchers discovered that ingesting protein during the training session enhances muscle tissue build up.

The breakdown of protein in the body is 8 percent lower in the CHO+PRO group, and protein production is 33 percent higher.

The researchers are not sure exactly how the protein supplementation causes this effect. Ingesting normal protein before training stimulates muscle build up because the protein means the muscles have more amino acids available after the training. The muscle cells need that protein for recovery. But PeptoPro – which consists of fragments of protein chains composed of two or three amino acids - enters the bloodstream almost immediately. So maybe it’s worth making sure that there’s an increased supply of amino acids to the muscles during a training session. The scientists suspect that this enhances the growth stimulus of the workout.

"Even in a fed state, protein co-ingestion prior to and during resistance type exercise improves whole-body protein balance and stimulates muscle protein synthesis during exercise", the researchers conclude. "Protein co-ingestion prior to and during resistance type exercise might be advocated to further improve skeletal muscle reconditioning during resistance-type exercise training."

Athletes who want to experiment with their protein intake during a training session probably won’t notice anything if they use ordinary proteins. It takes too long for the digestive system to break down the protein into pieces that are small enough to enter the bloodstream. But you could try pre-digested amino acids in a preparation like PeptoPro.

Am J Physiol Endocrinol Metab. 2008 Jul;295(1):E70-7.

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