Pre- And Post-Workout Protein Supplementation:


Getting In Enough Protein

Ok, so as you all know protein is absolutely essential for growth and repair of muscle tissue.  Pretty standard stuff! If you want to increase your size and strength development, then you are going to need good old protein to be able to do that successfully. No surprises there! Typically, most people can get away with around 0.8g protein per kg bodyweight daily, but if you are planning on lifting the cold hard iron, then your protein requirements are going to be much higher. Probably in a range of 1.2-2.0g per kg bodyweight daily. 

After all, this is pretty logical, with the increase in weightlifting, the extra volume and intensity you will be doing, is going to be putting your muscles through great deals of stress. Therefore, the extra protein is going to be essential in facilitating the optimal repair of your muscles, from this increased stress. So, what are we saying? Basically, protein is essential for growth and repair of muscle tissue, and becomes even more essential once you start subjecting your muscles to the iron.

Pre- and Post-Workout Supplementation: Can It Optimise Your Training Results?

One thing you might see many weightlifters doing is having some source of protein either before a workout, after a workout, or both! The rational for this is simple: protein synthesis. Protein synthesis is simply the building up of new proteins using amino acids and it’s really important! No protein synthesis, no new proteins synthesised and no new growth and repair of muscle tissue. Since protein synthesis requires amino acids, supplementing with protein/(like whey powders, milk, branched chain amino acid supplements) will provide those amino acids that can be readily used for protein synthesis. Having a readily available pool of amino acids can then ensure optimal protein synthesis in response to resistance-training stimuli, leading to potentially more size and strength development over time. But, what does the science actually tell us?

An important question to ask then:

Does supplementing with protein/amino acids pre- and post-workout lead to increases in size and strength in people over those that don’t supplement with protein or, in place of, supplement with a non-protein source pre- and post-workout?

What Does The Science Tell Us?

So, there has actually been a sizeable amount of research done on protein supplementation pre- and post-workout. Some people will tell you it’s essential if you want to successfully build up your size and strength. Others, will simply tell you: ’it really doesn’t matter whether or not you supplement pre- and post-workout with protein/amino acids, the difference in gains is negligible and simply blown way out of proportion through marketing tricks’. So like everything, there are two sides. Well, whatever side you choose, you might want to have a look first at the current research.

Why? Well, in fact, it has been found through a number of studies (some are listed below) that pre- and post-workout protein supplementation does lead to increases in lean body mass, hypertrophy, training session recovery, physical performance, as well as strength! So it all sounds really encouraging! 

Stark et al, 2012 compiled an array of studies, which demonstrated promising effects on size and strength development in response to pre- and post-workout protein/amino acid supplementation (I won’t list them all, but I will put down a few of the key ones!). 

•Study 1 (Post-Workout Only)•

In this study, 23 untrained men and women were split into three groups. Group 1 were given 20g casein at 1 hour post-workout. Group 2 was given 20g whey at 1 hour post-workout and Group 3 was given artificially sweetened water at 1 hour post-workout. The workout consisted of heavy leg resistance training. 

The results?

For both groups 1 and 2, a positive net muscle protein balance was observed, but not for group 3 (positive net protein balance is simply that protein formation was greater than protein breakdown – what you need for muscle growth!). 

The conclusion?

That the proteins in whey and casein resulted in an INCREASE in protein synthesis following training. 

•Study 2 (Post-Workout Only)•

In this study, 56 untrained males were split into three groups and underwent 12 weeks of 5 days per week resistance-training. Each group was given one of three beverages (each of 500 ml), and administered immediately and one hour following the workout. Group 1 was given fat-free milk. Group 2 was given an isocaloric, isonitrogenous, macronutrient-matched soy-protein and group 3 was given a isocaloric carbohydrate beverage. 

The results?

Measuring 3 days after the 12 week workout, it was found that those in group 1 and 2 (not 3) demonstrated significant increases muscle protein synthesis, bodyweight, decreased body fat and an increase in lean body mass.

However, the results of group 1 (fat-free milk) were significantly greater than those observed in group 2 (soy-milk). This is due to the lower bioavailability of soy than fat-free milk (bioavailability is simply the ease at which the body can absorb nutrients).

This meant that less protein was available to the body from soy in comparison to fat-free milk. This would have resulted in lower amino acid availability for muscle protein synthesis. 

The conclusion?

Post-workout supplementation with milk proteins (over non-protein sources) can act to boost muscle protein synthesis, resulting in increases in bodyweight, lean body mass and body fat reductions. 

•Study 3 (Pre- And Post-Workout)•

In this study, 33 strength trained men were split into two groups (+ a control group). Each group conducted a 10-week resistance training program. Group 1 consumed over the 10 week period a protein supplement comprising of a hydrolysed collagen-, whey- and casein-isolate both pre- and post-workout. Group 2 consumed over the 10 week training period the same protein supplement but this time once in the morning and once in the evening. The control group was not given the protein blend. The average calorie intake for each group was similar (and at their maintenance)

The results?

It was found that in both group 1 and group 2, there were no changes in body compositions with supplementation. Timing of supplementation here had no impact.

In both groups 1 and 2 there were significant increases in strength (1RM bench) over the control group.

The differences in 1RM bench strength between groups 1 and 2 were not significant, indicating timing of protein supplementation here had no impact on bench press strength. 

The conclusions?

Protein supplementation might help with the strength increases seen here in someones workout program. But the timing of this protein supplementation seems to have no major impact.

It’s also important to note that the participants all ate at maintenance calories (not sufficient for hypertrophy). This could explain the lack of changes changes in body composition with protein supplementation. Perhaps if the participants were eating above their maintenance, the results might have been different. 

•Study 4 (Pre- And Post-Workout)•

In this study, pre- and post-workout supplementation was used to investigate effects on recovery from resistance-training. 15 strength trained men were split into two groups. Group 1 were given pre- and post-workout protein isolates (consisting of hydrolysed collagen, whey and casein, with a mix of branch chain amino acids). Group 2 were given a pre- and post-workout placebo of maltodextrin. Each workout consisted of performing an initial 1RM on squat, bench, deadlift and lunge exercises (visit one), then on the second visit, performing at least 10 repetitions on each exercise at an intensity of 80%. On the next two visits (3 and 4), participants had to perform the exercises at the same weight as the last two visits (1 and 2), but this time, try to perform as many repetitions per set for 4 sets, as possible. The time between each visit was 24 hours. 

The results?

It was found that the group receiving the pre- and post-workout protein blend could perform more repetitions on visits 3 and 4 in comparison to those receiving the pre- and post-workout placebo. 

The conclusions?

That pre- and post-workout protein supplementation plays a role in enhancing weight training performance as well as recovery between sessions. 

•Study 5 (Pre- And Post-Workout)•

Unlike the studies above, which are relatively short-term in nature (10-12 week resistance training periods), this study looked at assessing the long-term effect of pre- and post-workout protein supplementation (21 weeks of resistance training). Here, participants were assigned 1 of 3 groups. Group 1 was given a 15g whey protein supplement, pre- and post-exercise. Group 2 was given a pre- and post-workout placebo. Group 3 was given no supplement and told to carry on with their normal exercise activities. Groups 1 and 2 performed 2 resistance sessions per week composing of upper and lower body multi-joint (compound) movements. 

The results?

It was found that group 1 (given pre- and post-workout protein supplementation) had exhibited greater increases in overall muscle hypertrophy than groups 2 and 3. 

The conclusions?

Pre- and post-workout protein supplementation is useful in promoting increases in muscle hypertrophy

Looking at these studies, it’s clear that there is mounting evidence to suggest that pre- and post-workout supplementation with protein can act to enhance a range of outcomes in response to resistance training: hypertrophy, lean body mass, strength, total bodyweight, recovery and exercise performance. As seen from the above studies, this seems to occur in both trained and untrained individuals, over a short-term training period (10-12 weeks), over long-term training periods (21 weeks) and, for a range of different protein sources (milk, whey, casein and soy).

Ok, so all sounds very promising, but there are a couple of important questions still to ask:

Why might pre- and post-workout protein supplementation have these positive effects on resistance training outcomes? What is happening at the physiological level?

When should pre- and post-workout protein supplementation be administered? We know there is a positive effect, but are their specific pre- and post workout windows of effectiveness? What happens if we take a pre-workout too early or too late?

What happens to pre- and post-workout protein supplementation effectiveness as progress (in terms of size and strength development) starts to slow down, as in very advanced trainers? 

Although there is are no clear answers to account for what was observed in these studies, it’s likely that they might arise from the positive changes in the magnitude and duration of muscle protein synthesis (MPS) (Reidy and Rasmussen, 2016). Why? Well, Reidy and Rasmussen explained that post-resistance training protein supplementation had a clear enhancing effect on both the magnitude and duration of MPS. The changes in MPS activity that occur after exercise in the presence of protein supplementation, could account for the positive changes observed in a range of resistance-training outcomes. 

The ‘Muscle Full’ Effect

Even though at this point it’s not exactly clear how post-exercise protein supplementation changes the MPS, it may be due to the ‘muscle full effect’ (Anderson and Smith, 2012).  Sounds weird but simply put, the muscle full effect is how a muscle maintains homeostasis (constant mass). This is important because muscle tissue is undergoing a constant state of breakdown and repair through MPS and MPB (muscle protein breakdown). In a fasted state, periods of stress and exercise, MPB will be greater than MPS. In the fed state, MPS will be greater than MPB. The ability of muscle tissue to balance out MPS with MPB (also known as nitrogen balance), is what allows it to maintain a constant mass.


Figure From Anderson and Smith, 2012. To show the magnitude and time course of MSP (black line) and the amino acid content in circulation for MSP (red line)  in response to exercise. Notice the ‘lag’ between the red and black lines. When the muscle is full, it no longer needs the remaining amino acids. This is why the black line remains elevated (amino acid content in circulation) even when the MSP has dropped right down. 

In order to understand the muscle full effect, it’s important first to look at nutrition what’s happening with MPS in response to food intake. Essentially, when you eat, you are in an anabolic state (MPS is greater than MPB) and when you fast, you are in a catabolic state (MPB is greater than MPS). When food is digested, the available amino acids from that food, will enter the blood circulation and head into the muscle (known as an amino acid flux – sounds cool!). These amino acids can be utilised by the muscle for MPS in order to replace muscle proteins lost to a range of different energy processes in the body (MPB). However, because it takes time for the amino acids to be derived from food, enter the blood stream and then flow into the muscle, there is a ‘time lag’ between amino acid circulation and MPS onset. However, once MPS gets going, you will find that MPS will keep going until the muscle has replaced these lost proteins and returns to homeostasis (muscle ‘full’ – MPS balanced with MPB). Even though the concentration of amino acids in circulation is still high, the muscle doesn’t need them. 


This could also explain why the MPS is increased in magnitude and duration following exercise with post-exercise protein supplementation. During exercise you are essentially in a catabolic state (MPB is greater than MPS) and so you are probably going to be needing a quicker and longer MPS after exercise to switch the muscle back into an anabolic state (in order to balance out the increased MPB during exercise). After all, it’s a little counter productive if you stay in an anabolic state after exercise! Not good for maintaining and making new gains! As a result, exercise is likely to delay the muscle full effect allowing for a longer influx of amino acids from the blood into the muscle for a longer and greater peak in MPS. This is why protein supplementation probably has a beneficial effect after a workout. The supplemented protein can supply the quantify of amino acids needed to prolong the MPS. 

In terms of nutrient timing, Anderson and Smith suggested that it might not actually matter. Why might this be the case? Simply because it has been found that exercise can increase the sensitivity of muscle tissue to nutrient uptake after training. Moreover, this increased sensitivity can last up to 24 hours, which means it doesn’t matter if you take the protein supplementation pre- or post-exercise. However, depending on the extent of MPB during your exercise session (depending on intensity, volume used etc.), it may not be wise to wait too long to get MPS back up to par! 

In a study published by Hiroyasu Mori, 2014 it was found that the nitrogen balance in trained men was significantly lower than in untrained men. Nitrogen balance is simply the balance between MPS and MPB. When the nitrogen balance is positive, this means that MPS is greater than MPB and thus favours muscle growth. A reduction in positive nitrogen balance would signal that the MPS exhibited in trained individuals post-exercise was shorter in duration and peaked earlier in contrast to the MPS exhibited by the untrained group. This would suggest that an attenuated MPS would likely lead to lesser production of muscle building proteins as training experience increased.

My Recommendations:

It’s clear that pre- and post-workout protein supplementation can have a positive impact on resistance training outcomes (although the effectiveness is likely to vary depending on your level of training experience!).

In the grand scheme of things, the major results will still come from keeping track of your calories and having an optimal training program in place. It’s not clear how big of a long-term impact pre- and post-workout protein supplementation would have in comparison to training and nutrition alone.

Overall, it’s not quite clear what exactly the balance is between calorie intake, optimal training programming and pre/post-workout protein supplementation in size and strength development. But I believe that calorie intake and training programming are going to account for the majority of progress you make.

Any questions, ask away!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this:
search previous next tag category expand menu location phone mail time cart zoom edit close