Protein Series Post #2 – Supplementation

by Roberta MacPhee, RD on March 13, 2014

Disclaimer: this is a HUGE topic!  There are thousands of different brands and types of protein supplements on the market and new ones emerging daily. In this particular post I plan on discussing the heavy hitters in the protein supplement world: whey, casein, soy and other emerging plant proteins.  These are very brief discussions on each type – keep in mind that I could write multiple blog posts on each type on their own, there is a lot to discuss!  However, I am attempting to focus solely on descriptions of each and rates of absorption..let’s see how this goes! For those that missed my Protein 101 post, I recommend reading it before continuing to read this post!

Whey Protein
If you walk into any supplement store in Canada you will see hundreds of different brands of whey protein – this is the most popular type of protein supplement and the most widely researched.  Whey protein is a “complete protein” derived from milk and is most commonly produced as a supplement in two forms: whey concentrate and whey isolate.  Isolate is the superior product as it is more concentrated (confusing, I know!) and has only small amounts of other compounds in it, such as lactose, therefore making it more appealing and acceptable for a larger number of people.  Whey protein is considered a “fast absorbing” protein and research shows that when ingested immediately after exercising (or no later than one hour post exercise) it helps to promote muscle protein synthesis and speed up the recovery/repair of muscle tissue and fibers.
Casein Protein
Casein is also derived from milk and is similar to whey in that it is also a “complete protein” providing all essential amino acids. However, it is very different from whey in the speed of absorption.  Casein is absorbed at a slower, more prolonged rate.  Protein supplements that are mainly composed of casein proteins are not as widely available as whey supplements as the demand is not as high (supply and demand!).  They can still be beneficial for muscle protein synthesis and repair, however not as many amino acids will get to those tissues when needed most (in that critical 1hr post exercise window) so depending on the level of damage or need, you may be at a disadvantage if you rely on casein protein supplements post exercise.

Soy Protein
Soy protein supplements are derived from soybeans and are therefore classified as a plant protein, however they do provide all essential amino acids and therefore are “complete” and comparable to whey and casein supplements.  Like whey, soy protein supplements are produced as either concentrate or isolate varieties.  Again, like whey, the isolate form is the more concentrated and widely available form.  In terms of speed of absorption and recovery/repair of muscle tissue post exercise, soy protein supplements are more similar to casein – they are slower to be absorbed.

Other Plant Proteins: Pea, Hemp, Rice, etc
These types of protein supplements are “incomplete proteins” as they do not contain all the essential amino acids needed to build and repair tissue.  Some of these types of proteins are newer to the market and therefore have limited available research on amounts and speed of absorption, however we know that they are incomplete therefore making them an inferior choice to a whey, casein or soy protein.  In terms of rate of absorption, one study classified rice protein isolate as an “intermediate” protein – it is absorbed a little faster than casein, but slower than whey.  Many people will choose these types of proteins based on a diet they are following or allergies.

Choices, Choices, Choices..
So, how do you know which supplement is right for you or if you even need one in the first place?  Well, that depends on a number of factors such as what type of exercise you do, how often, when your next bout of exercise will be and what your current diet looks like.  If you are considering a protein supplement, talk to Bethany before choosing.  These can be expensive products and you want to make sure you are choosing the right one – everyone’s needs are different!
Something I need to make note of before “signing off” on supplements is a message that was repeated in almost every research article, paper and book I read:  you need to make sure you are getting enough protein in your diet to ensure you are not using protein as a source of energy during activity BUT most recreational athletes (exercise 3-4x per week) can achieve muscle protein synthesis and repair with whole foods and a daily protein intake of approximately 1.2-1.7grams/kg – so have a look at your current intake before heading to your nearest supplement store!  Also, suggested amounts of 10-20grams protein post exercise were said to be adequate, which can be easily consumed using whole foods (i.e. ½ – ¾ cup Greek yogurt).  This is highly dependent on the exercise completed and the pre exercise snack/meal (if any) but it provides a reference point to consider.

P.S – speaking of pre-exercise snacks/meals..stay tuned for some new research on this topic in a future blog post, interesting stuff emerging on this topic!

Clark, N. (2008). Nancy Clark’s sports nutrition guidebook (4th ed.). Chestnut Hill, MA: Human Kinetics
Jager, R. et al. (2013). Comparison of rice and whey protein osolate digestion rate and amino acid absorption. Journal of the International Society of Sports Nutrition: 12
Rubin, B., Hashim, J., Sharp, S., and Antonio, J. (2012). Thermic effect of soy vs. whey protein – a pilot trial.  Journal of the International Society of Sports Nutrition: 26
Poortmans, J.R., Carpentier, A., Pereira-Lancha, L.O., and Lancha Jr., A.(2012).  Protein turnover, amino acid requirements and recommendations for athletes and active populations.  Brazilian Journal of Medicaland Biological Research 45(10). 875-890.
Dietitians of Canada, American College of Sports Medicine, and the American Dietetic Association Joint Position Paper (2008). Nutrition and Athletic Performance.

Previous post:

Next post: