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 By: Shamir Karmali
This article will introduce the subject of whey protein in the context of resistance training. This article will not evaluate branded supplements. It will discuss the scientific evidence surrounding an active ingredient. I am not affiliated with any supplement company and thus these articles are non-bias. If it works it works, if it doesn't it doesn't.
  Click Image To Enlarge.This Article Will Introduce The Subject Of Whey Protein In The Context Of Resistance Training.
Whey is a type of protein found in milk. It is digested and absorbed into the body very fast which has led to people suggesting its use in acute states of muscle catabolism, e.g. after a workout or upon waking in the morning. Essentially whey protein with fat and carbohydrate (lactose) removed so that less than 90% of the product is composed of protein (i.e. less than 90g out of every 100g). Hydrolysed whey protein is where peptides are further broken down to make absorption faster.
 Click Image To Enlarge.Whey Is A Type Of Protein Found In Milk.
There are a variety of benefits of consuming whey protein, these include:
We are only going to discuss the last point in this article.
Resistance training results in increases in lean body mass (LBM) through a variety of mechanisms. One such mechanism is by causing micro-tears in the muscle fibers. Once we eat and insulin levels rise, the body shuttles more protein into the muscles to make the cells bigger (hypertrophy) and consequently stronger so next time it will not tear as easily. (Note that although muscle size is not the only factor affecting strength, it is a very important factor).
 Click Image To Enlarge.Resistance Training Results In Increases In Lean Body Mass (LBM) Through A Variety Of Mechanisms. Because weight training is a catabolic activity (it breaks down the body tissues such as muscle), it is logical that upon completion of the workout, one would want to reverse this to an anabolic state as fast as possible. This is where whey protein comes in. Whey protein is said to have:
As such whey protein is associated with a short, sharp rise in plasma amino acids and greater protein synthesis than slower digesting proteins such as casein. However due to whey's rapid absorption and short-lived effects, casein may be more efficacious for longer-term prevention of protein breakdown.
Essentially whey protein would be best to acutely increase protein synthesis and at all other times, slower digesting proteins like casein would be useful to prevent muscle breakdown.
Biological value simply refers to how much of the protein ingested is broken down and used to synthesize proteins the body needs. It is expressed either as an absolute number (called the 'true percentage utilization') or percentage relative to another protein (this is called percentage utilization relative to another already established and utilizable protein source, most commonly egg). Egg protein is the 'gold standard' and is thus given a value of 100%. Whey protein isolates have been found to reach BVs greater than 100%.
 Click Image To Enlarge.Whey Protein Isolates Have Been Found To Reach BV's Greater Than 100%. Theoretically, this should mean whey protein is a more efficient protein source than the gold standard of egg. BV can be seen as an indicator of the quality of protein.
BV depends on several factors; its preparation (e.g. cooking may denature proteins), concomitant vitamins and minerals (which may compete or enhance absorption) and most importantly amino acid profile. There are 9 essential amino acids (EAAs) meaning your body can't make them and they must be obtained from the diet. The amino acid that usually limits the biological availability of protein is lysine.
This also explains why sources of protein such as pulses, starches, fruits, etc. have low biological value - as they lack at least one of the essential amino acids. This is what is meant when people refer to a protein-containing food as 'incomplete'.
Outcomes assessed included body composition (by dual energy x-ray absorptiometry, DEXA), muscular strength (1 repetition maximum, 1RM) and plasma glutamine levels (as a marker of protein synthesis) Results: The hWPI group gained more LBM, loss more fat and added more to their 1RM than the casein group. No differences were seen between groups regarding plasma glutamine levels. Conclusions And Criticisms: This study suggests that hWPI may confer greater benefits from resistance training programs than the same amount of protein (isonitrogenous) in a different form (casein). However the sample size was very small and thus underpowered to rigorously assess the outcomes discussed above. Furthermore the duration of the study was short and thus no comment can be made on long-term benefits of hWPI. Lastly this study did not investigate whether there was an optimal time to consume protein.
Outcomes assessed included body composition, muscular strength and muscle hypertrophy properties (cross-sectional area-CSA, muscle fiber type and contractile protein content). Results: The PRE-POST group showed greater improvements in 1RM, LBM, body fat % and markers of muscle hypertrophy (CSA, contractile protein content, type II muscle fiber hypertrophy) than the MOR-EVE group. Conclusions And Analysis: Similar criticisms as discussed above apply to this study, i.e. it has a small sample size, was of short duration, etc. How much we can attribute the results of this study purely to WPI is difficult considering other ergogenic supplements such as creatine were given. Nevertheless this study clearly demonstrates that despite the individuals consuming their normal diet, there was still a clear difference between groups and a clear effect of supplement timing. Therefore the best time to consume WPI is just before and just after a workout.
 Click Image To Enlarge.The Best Time To Consume WPI Is Just Before And Just After A Workout.
The mechanisms behind whey protein supplementation and protein synthesis are beyond the scope of this article. However, they occur on a variety of cellular and molecular levels. Proposed molecular targets include the mTOR (mammalian target of rapamycin), p70-S6k and pax7 gene. There is also evidence that it affects overall balance of protein turnover by manipulating cysteine levels and thus reducing the urea cycle and muscle catabolism.
A variety of factors may affect the results achieved by taking WPI. These include adjuncts such as creatine monohydrate, carbohydrates (to provide insulin spikes) and blends of different proteins (e.g. WPI with casein). Although blunted responses to protein have been associated with increasing age, there is evidence that even elderly individuals may derive benefit from high protein meals/supplements. Whey protein may be suitable for all ages and levels of performance status (i.e. recreational, sports athlete, etc). The optimum quantity is about 2 grams per pound of bodyweight.
Protein supplements comprise a large proportion of products in the bodybuilding market. This article has looked at some of the evidence to support its use for recreational bodybuilding purposes. However the benefits may not be limited to this group only, and may be of use in a variety of other contexts such as in medical diseases (e.g. wasting states). Nevertheless WPI may offer an efficient and convenient method of improving body composition and performance in resistance training.
References:
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