What's The Deal with Protein

If you've frequented the gym any time in the past little while you'll have noticed, or perhaps heard, the little wire sphere bouncing around in plastic bottle, shook by "hardcore-look gym rats" (as is often the term muttered by some of the more slight runners I've bumped into at the gym). Amongst groups of these inverted triangles you may hear utterances of "whey", "casein", "alanine" or something along those lines. What does it all mean? And why should you care too?

Protein is an essential part of your diet. It is needed to keep your body functioning, be it from building and regenerating muscles, down to the intricate nature of how your body works- enzymes and cellular signaling functions. In terms of training and running, protein supplementation has been studied time and time again and proven effective when trying to build or maintain muscle strength and improve regeneration post exercise. Yet, what protein source is the best? When should you take it? Before you work out? During? After? When's the best time to take it? In today's blog we're going to look at some of the science behind protein supplementation.

The Basics

Protein- The basics

Proteins are chains of 20 (or 22 if you add the two additional created by genetic code) Amino Acids, 10 of which are considered essential to human adults. Essential Amino Acids (EAA) are ones that humans cannot create ourselves, we must take them in from external sources in order for us to be able to create some of our own enzymes and proteins. When our body is starved of proteins, we call this being in a state of negative nitrogen balance. Nitrogen Balance = Nitrogen intake - Nitrogen loss. Being in a negative nitrogen balance means you are losing more nitrogen through urea than you are taking in via diet. This creates a whole host of  problems, least of which includes muscle wasting and degradation.

Nitrogen Balance and Amino Acids- Phillips 2004- Nutrition

Thus, to build muscle we want muscle to be in positive energy balance- the reason why protein supplementation post exercise is so important. If you resistance train or work your muscles to the point of exhaustion (any kind of exercise really) you can go into negative protein balance. By eating food loaded with protein or supplementing with amino acids, you can decrease the breakdown of muscle protein and maintain a positive balance needed to gain muscle mass and maintain muscle growth- especially important for those shorter-end running events or recovering after long runs for distance athletes.

Protein Balance and degradation- Phillips 2004-Nutrition

But what's the optimal dose? How much protein supplement do I have to take to get the maximum effects? is it just the one scoop that they give me? or do I need two? What's the deal? Much research has shown that the perfect dose is right around 20g of protein post workout. You're more than welcome to take more, but the relationship between the fractional biosynthesis rate (FSR) and protein intake is asymptotic, not linear. This of course varies person to person based on individual physiology, but the fact remains that the process is saturable, there are only so many amino acid transporters that we have to be able to move amino acids into our body. 

The leveling off of Protein Synthesis Rate with increase supplementation- Moore 2009- Am J Clin Nutr.

So, if protein supplementation is good, all amino acids must be good right? Not so, Essential Amino Acids are just that, essential (Emphasis). 18g/day of EAA has the same benefits as taking 40g/day of whole source/mixed sources of amino acids. There seems to be something about EAA, specifically one in particular- Leucine, which is playing the role of muscle bio synthesis. 

So, you've looked around for the best source of protein but wait! You've hit a snag! You've come across sites that claim their protein source is the best! 

Whey- Milk derived protein source

"Why protein (the highest quality and the best form of protein) is incredible stuff. It provides the body with the necessary building blocks to produce amino acids that are used for building muscle tissue. Whoa! Nearly every bodybuilder know the importance of protein supplementation. Studies have been conducted that compare whey whey protein to other sources. They have found that whey protein contains the perfect combination of overall amino acid makeup... and in just the right concentrations for optimal performance in the body." ~bodybuilding.com/store/whey

Casein- Beef derived protein source

"Beef protein is specifically designed to allow the recycling of amino acids back toward the muscle-building pathway and prevents and prevents the build-up of debilitating toxic scavengers such as ammonia. This amazing product is the only protein with this technology that is capable of recycling aminos back into the anabolic muscle building pathways for increased nitrogen retention and improves muscle growth and performance." 

~fabmuscles.com/index.php?main_page=product_info&products_id=230

Two hilariously written product descriptions about two different protein sources. Odd that Soy protein didn't have such a hilariously macho write up...

Regardless of the hilarity of the body building sites, the question still remains, which protein source is the best? 

Whey vs Casein vs Soy

Most supplements on the market today are made of whey-derived sources of protein. Whey is considered a "fast" source of protein, casein a "slow" source, and soy falls somewhere in between as an intermediate source. Ingestion of whey, when compared to casein, results in rapid gastric emptying and quick amino acid spike within the blood (why it is referred to as a "fast" source- it is digested and enters the blood faster than casein). However, because it enters the blood so quickly, it also results in a larger insulin spike- likely due to the higher Leucine content in whey than in casein.

Whey Insulin Spike vs Soy & Casein In Blood- Tang et al 2009-J Appl Physiol

Leucine blood concentrations Whey vs Soy vs Casein- Tang at al 2009-J Appl Physiol

Each group was matched for essential amino acid content, 10g total, yet the big differences were because of Leucine content and the insulin spike. And while some may scoff at such a high insulin spike, challenging that it damages your body and increases your chance of type II diabetes, this suggest that the spike of insulin is required to increase biogenesis of the muscle.

But what about a functional measurement of muscle synthesis? Well, it would appear that Whey has the highest fractional synthesis rate of the three protein sources. 

FSR Whey vs Casein vs Soy- tang et al 2009-J appl Physiol 

*However, casein is called a slow reactor for a reason. The time scale of the previous data MAY have been to short and it didn't last long enough. Unlikely, but perhaps a flaw in the previous study to consider.*

Importance of Timing

So you've selected Whey protein as your choice for a recovery supplement. Now what? When should you take it in relation to working out for best results? Well, depending on the length of your planned workout, ingesting before may be more beneficial. Protein takes time to be broken down into usable amino acid fractions (~45min). By ingesting before your workout, you are "priming" the system and setting it up for immediate use post exercise. It may be worth splitting your 20g protein dose into two doses- 10g before and 10g after. Protein synthesis is still highest post meal/exercise, but you can prime the system to speed the process along.

Recommendations

So how much do we actually need? 

-Sedentary people need need about 0.8g/kg body weight/day of protein

-Strength athletes needs about 1.4  to 1.7g/kg body weight/day

-Endurance Athletes: 1.2-1.4g/kg body weight/day

Protein use can seriously improve performance because o the gains seen through faster recovery. It is important to keep this in mind while training and looking to get the most out of your athletic performance. 

Check out our the Runner's Mark website for more info and be sure to check out some of our protein supplements in our shop section.

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