Your Post Workout Protein: Are You Getting Enough?

For some time now it has been the accepted recommendation that to get maximum muscle protein synthesis (MPS) after weight training then you need to consume 20–25 grams of good quality protein post workout. When you get maximum muscle protein synthesis, you’re getting the best repair and building of muscle cells and ultimately, muscle mass.

There have been some minor variations to this with age related recommendations pushing it to 30 grams for those in their forties or older, but the base principles have remained the same for some time now.196

Until recently!

Researchers in the UK started to wonder if this broad population based recommendation made sense for everyone. They wondered if people with large muscle mass would get the same benefit as those with less muscle mass. It would seem a logical conclusion that the more muscle mass you have, the more protein you would need to kick of the muscle building and repair process. So being scientists they came up with a study to answer the question…

Does lean body mass (a person’s weight minus the amount of body fat they carry) affect the amount of protein required post work out for maximal MPS?

Why do we even take protein after weight training?

When performed effectively, weight training causes damage to the muscle cells. Following this “damage”, protein is essential to stimulate the process of growth and repair of the muscle. If you want to get the best results from your weight lifting efforts, then you want to get the maximum amount of MPS you can achieve. Because maximal MPS is essential in this recovery process, the amount of protein required to achieve it has been intensively researched, and it’s from these studies that the figure of 20–25 grams of protein has been established.

While 20 or 25 grams seems like a reasonable number based on the available data, this number has not been tested for muscle mass. Surely people with greater muscle mass would need to increase the amount of protein required after exercise to reach their maximal MPS. They certainly seem to need more at the all you can eat buffet! To look at this question, researchers in a recent study tested the idea that those with greater lean mass (i.e. had more muscle) require more protein to stimulate maximal MPS after training. 197

What did they discover?

Not what they were expecting!

Their hypothesis was that lean body mass would affect the amount of protein needed to get maximum MPS. They tested this by having two different study groups, the first included subjects with low muscle mass (defined as lean body mass (LBM) less than or equal to 65 kilograms) the second group of subjects were those with a higher muscle mass (they had a LBM of 70 kilograms or more). So now they had two groups to test their hypothesis, but they added another variable — The amount of protein ingested after training. These two groups were split again into two groups (four groups in total), one was given 20 grams of whey protein isolate (WPI) dissolved in water immediately after a whole-body resistance exercise program, the others given 40 grams of WPI after exercise.

What they discovered was contrary to the hypothesis, for both the low muscle mass group and the higher muscle mass group, the MPS changes were similar between both groups at the two different dosages. Therefore, the logical conclusion was disproved (I love science)!

What was even more surprising (and the reason for this article!), when all the subjects were combined the researchers did discover a statistically significant result. Despite which lean body mass group the subjects belonged to (either having higher or lower muscle mass), after whole-body weight training the MPS was 20% higher with 40 grams of whey protein compared to 20 grams of whey protein.

This study showed that 40 grams of whey protein isolate induced greater MPS than 20 grams in both high and low LBM groups. But what about the results from all those previous studies suggesting that MPS after exercise is maximized after ingesting 20–25 grams of high-quality protein?

Just tell me how much protein to take after a workout!

One of the best explanations for the variation in dosage recommendations comes down to not asking how much muscle someone has, but how much muscle did they use during exercise?

Many of the studies that recommended the 20–25 grams of protein for maximal MPS after exercise used leg-only workouts, whereas the present study used a whole-body workout protocol.198, 199

It may be that the greater overall amount of muscle mass activation during exercise may influence protein requirements for maximal post-exercise protein synthesis.

Although more research is needed with larger experimental groups (and with different age groups), the evidence is sufficient to suggest that those consuming only 20–25 grams of good quality protein after training may benefit from taking 40 grams. If you are looking to get the best muscle building response from a full body weight session it is important to get enough of a high-quality protein. But are we better to just get enough, and is there any harm in getting too much?

This study suggests that bumping up post-workout protein consumption from 25 to 40 grams will get the best results.

At worst, if you end up consuming “excess” protein I don’t think the extra 60 calories from the 15 grams of additional protein is likely to disrupt even the most stringent of diets.

What do you think? Are you willing to boost your post workout protein drink towards 40 grams? Give us your opinion in the comments below.

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