Given that a rise in muscle mass is based on the balance between increased protein synthesis and reduced catabolism - it begged the question: "could a combination of both be BETTER?"
So another study (2) looked at both whey and casein AFTER resistance training, with the authors noting: "It could be argued that the combination of whey and casein would be an optimal choice post exercise."
Then there was more research (3) that looked at plain old milk (80% casein 20% whey) compared to soy milk (rapidly digesting) - and found milk to be the superior option.
To quote from the paper's conclusion: "Consumption of low-fat milk appears to create an anabolic environment following resistance training and over the long term with training, it appears that greater gains in lean mass and muscle hypertrophy can be obtained. Furthermore, milk may also lead to greater losses of body fat when it is consumed following resistance training."
So it seems the combination of the two is better then just the faster absorbing whey or soy option, that is still touted by many as your best choice.
Now if you have no issues with lactose, or you're on a tight budget - then milk could be a great post-workout option for you!
THE POST WORKOUT BLEND
Aim for 0.5 grams of PROTEIN per KILOGRAM of bodyweight.....with about roughly 70% coming from WHEY and 30% from CASEIN, in light of the milk research (3).
PRE-WORKOUT
Whey protein is the much better option here.
The higher spike in blood amino acid levels is what we're after, right before we begin training, to prevent any breakdown of muscle mass whilst we train.
Furthermore, whey protein results in a 8.5% HIGHER resting energy expenditure (4) 24 hours after your workout, meaning you're burning MORE calories!
This is due to the high metabolic cost of protein synthesis - the building and repairing of new muscle.
SHOOT for 20-25g of WHEY protein before training.
BEFORE BED
The other time in which Casein protein can be beneficial is BEFORE bed.
Given the 7-8 hours it takes to digest, it's the perfect option for optimal blood amino acid levels whilst you sleep!
However, a similar effect can be achieved with a meal high in protein with casein products (e.g. milk or cottage cheese) together with fats and vegetables to slow digestion.
But the benefit of casein in this regard is that it will provide you enough for your overnight fast, for minimal calories.
(Not that fasting is as bad as some people might think - read more
HERE.)
So go with which ever option appeals more to you!
ABSORPTION TIMES
Here's some data on the rate in which protein powders absorb:
|
Protein type
|
Rate of Absorption (g/hour)
|
|
Pea Protein
|
3.5
|
|
Milk Protein
|
3.5
|
|
Soy Protein Isolate
|
3.9
|
|
Casein Isolate
|
6.1
|
|
Whey Isolate
|
8-10
|
You can see that whey isolate is the fastest absorbing of the lot, digesting at around 8-10 grams an hour.
BIOLOGICAL VALUE
The other benefit of protein shakes (whey especially) is that they are exceptionally high in what's called a biological value.
A biological value is a score that looks at the nitrogen that enters your body, versus how much is actually absorbed.
|
Protein type
|
Biological value
|
|
Hydrolysed whey
|
100
|
|
Whey concentrate
|
100
|
|
Whole egg
|
100
|
|
Beef/poultry,fish
|
79-83
|
|
Soy
|
74
|
|
Casein
|
71
|
|
Milk
|
91
|
Table adapted from (5).
You can see how effective whey protein is in this regard!
SHAKES v WHOLE FOODS
A combination of both is important.
Protein shakes are ideal for in around workout times due to the faster spike in amino acid levels they provide, and the high biological value score they carry, as outlined above.
They are much easier to digest then whole foods, and are MUCH more convenient. Given they are taken with water, they assist with the rehydration process.
Some people find whole foods harder to eat after training, not to mention they might not be getting the adequate protein/carbohydrate ratio from their chosen meal.
However, for all other meals of the day, whole foods are your best option!
Stay Fit, Stay Flexed!
REFERENCES
(1) Boirie Y, Dangin M, Gachon P, Vasson MP, Maubois JL, Beaufrere B. Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci USA. 1997, 94(26):14930-5.
(2) Reitelseder S, Agergaard J, Doesing S, Helmark IC, Lund P, Kristensen NB, Frystyk J, Flyvbjerg A, Schjerling P, Van Hall G, Kjaer M, Holm L. Whey and Casein labeled with L-[1-13C] leucine and muscle protein synthesis: effect of resistance exercise and protein ingestion. Am J Physiol Endocrinol Metab. 2011 Jan; 300(1):E231-42. doi: 10.1152/ajpendo. 00513.2010. Epub 2010 Nov 2.
(3) Roy BD. Milk: the new sports drink? A Review. J Int Soc Sports Nutr. 2008 Oct 2;5:15
(4) Hackney KJ, Bruenger AJ, Lemmer JT. Timing protein intake increases energy expenditure 24 H after resistance training. Med Sci Sports Exerc. 2010 May;42(5):998-1003.
(5) Kreider RB, Kleiner SM. Protein supplements for athletes; need v convenience. Your Patient Fitness 2000;14(6):12-18.
