Post-Workout Protein Intake

How Much Protein is actually needed?

Do I need to buy protein powder? Is whey better than casein? Should I pay extra for isolate or hydrolysate? How much should I take?

These are just a few of the many questions surrounding post-workout nutrition.  And unfortunately, with the availability of inflated and conflicting information online, finding a reliable answer has become quite difficult.

Hence, the reason for this article, which tackles the science, delivers the facts, and helps you decide what product and protocol is best for you (and your clients).

Why Post-Workout Protein?

The first thing to understand is the purpose of post-workout supplementation.  Especially since many of you reading this have been purchasing these magic pills and powders for years with no clue why.

Reason #1

Muscle Protein Synthesis, or MPS, which is already elevated because of resistance training. MPS can also be further elevated with the administration of the amino acids in protein.

More MPS Elevation = More Protein Absorption = More Muscle Growth

Reason # 2

The second reason for consuming protein after a workout is to spike insulin levels. Insulin is the storage hormone. In other words, it’s going to shuttle glucose and amino acids into muscle tissue. More importantly, insulin is the hormone that inhibits cortisol.  Simply put, insulin is going to diminish the exercise-induced stress as well as prevent further breakdown.

To sum up, post-workout protein shifts the body from a catabolic state, into an anabolic one.  It does so not only by delivering amino acids that elevate MPS and insulin, but also by inhibiting MPB (muscle protein breakdown) and cortisol.

What Protein is Best?

With respect to type, liquid proteins fare better than solid ones, because of their absorption speed. And of these liquid proteins, whey is superior because of it’s amino acid profile.


Per 25g Leucine EAA BCAA
Whey 3.0 12.4 5.6
Casein 2.3 11.0 4.9
Soy 1.5 9.0 3.4

Note: Just because soy appears in this chart (and the graph below), doesn’t mean it’s a front-runner.  Soy is toxic to humans (in all forms), and research suggests that soy protein isolate actually decreases muscle strength, lowers testosterone, and increases cortisol when consumed post-workout.

The branched chain amino acids (BCAA’s) in whey make sure insulin is maximally stimulated. In particular, the high leucine content is being responsible for the above average elevation in MPS.


Interestingly, this also means you can get a similar effect from taking a leucine-rich BCAA supplement.  This has been shown nicely in this 2008 paper in the American Journal of Physiology Endocrinology and Metabolism. Researchers found a 145% increase in MPS in a group given 20g of ‘leucine enriched’ EAA’s and 30g of carbohydrates 1hr after exercise, compared to 41% in a group given none.


The Health Benefits of Whey

And let’s not talk about the fact that might be missing out on some of the extra health benefits whey offers. Namely it’s content in lactoferrin, albumin and lactalbumin. Those are largely driven to the immune protecting antibodies (IgA), along with amino acids (like cysteine). Together, they support the production of an extremely important antioxidant – called glutathione. This antioxidant can:

  • Improve nutrient absorption
  • Increase serotonin and cognitive function
  • Inhibit the growth of pathogenic bacteria (like E. coli)
  • Reduce oxidative stress and neutralizing toxins
  • Improve fasting glucose and insulin sensitivity
  • Encourage the growth of beneficial (probiotic) bacteria
  • Protect against tumor growth and reducing cancer risk
  • Reduce liver fat
  • Improve bone healing and preventing bone loss
  • Elevate resting energy expenditure and fat oxidation
  • Reduce heart disease risk – blood pressure, lipid profile, and vascular function
  • Improve symptoms of autism and depression
  • Protecte against asthma, eczema and food allergies

Despite conventional thinking, whey is also the protein that we’re less likely to be sensitive to.  Since, unlike casein-rich cow’s milk, it’s the predominant protein in breast milk (3:1), it is more easily digested by humans.

What Whey is Best?

Ask the greased-up meat-stick at your local supplement shop, and he’ll have you purchasing a big expensive tub of Whey Hydrosylate.  But ask the “Real Food” advocates and they’ll send you on a search for raw milk from ethically-raised animals that only graze on the finest blades of grass.

So, why do you listen to?

Well, you listen to what’s aligned with your personal goals.  As if you’re training strictly for disease-prevention and long-term health, Raw Dairy is your best bet, and if you’re training for strictly physique improvements, Whey Hydrosylate (or a BCAA supplement) will suffice.


For those in between (that want it all), your best bet is a high-quality, non-heated (undenatured) whey concentrate or isolate product.  Since these powders still contain many of the immune-boosting properties found in raw dairy, but still elevate your insulin and MPS levels to a respectable level.


When comparing the two directly – isolate or concentrate – it comes down to personal preference.  As, on the one hand, whey concentrate is more affordable, and tends to contain more of the health boosting properties.  On the other hand, whey isolate has a greater impact on MPS, and tends to have less lactate and carbohydrates.

Generally speaking, those exercising with the primary objective of burning fat may want to favour an isolate product. Since, as we discussed at the start, protein powder alone does a pretty sufficient job of elevating synthesis and inhibiting breakdown, there is often little need for extra carbohydrates (and additional insulin).

And similarly, those looking to build muscle, or those looking to fuel a heavy training load (especially if it’s the high-intensity, glycolytically demanding kind) may want to favour a concentrate product (with some carbohydrate), as this is the prime opportunity to replenish their glycogen stores.

Is There an Optimal Dose?

The simple answer is “yes,” though it varies based on the individual.  And recent evidence suggests, that it could also vary based on the workout.

For instance, in healthy young men 0.3g of whey and 0.04g of leucine (per kg of bodyweight) appears to maximally stimulate MPS, but these values need to be higher when looking at older participants because of an increased level of anabolic resistance (decreased sensitivity/absorption).


In 2012, researchers in the British Journal of Nutrition found that a whey protein dosage of 40g (0.5g/kg of bodyweight) was necessary to maximally stimulate MPS in elderly participants after resistance training.

Likewise, recent evidence released in August of this year (2016) suggests that we may need to double these amounts if we’re talking about a full-body training session.  As researchers in the journal Physiological Reports demonstrated greater MPS elevations at 0.6g/kg compared to 0.3g/kg for those taking part in a 3 set, 10 rep routine of chest press, lat pull‐down, leg curl, leg press, and leg extension.  And when you go back and look at the evidence from the past (suggesting 0.3g/kg), you realize that the participants only ever trained the lower body.

Perhaps this suggests that we should be matching the protein amount to the nature of the training session – with greater muscle recruitment requiring greater doses of post-workout protein.


Article credit: Charles Poliquin

Post-Workout Protein – A Closer Look