Protein Shake Before Or After Workout: Maximise Your Results

Written by Ben Carlisle

Last updated on: Mar 22, 2022

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You can drink a protein shake before or after a workout. The aim of a protein shake is to boost your protein consumption and provide the essential amino acids necessary for muscle recovery and growth. With regards to whether there is an optimal time to drink a protein shake the research is conflicted. Read on to find out more…

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The Purpose Of Using Protein Powder When Training

When followig a training program the purpose of a protein shake is to make sure you are hitting the required protein levels to reach your goals. The Recommended Daily Allowance of 0.36 grams of protein per pound of body-weight (0.8 grams per kg) is not a guide on consumption of protein for muscle recovery and growth. It is to avoid a protein deficiency. In order to provide your body with enough protein to for muscle recovery and the development of lean muscle tissue a significantly higher total protein intake will be required (1).

Research has found the use of protein supplements combined with prolonged resistance training significantly enhances muscle size and strength. Increased age has been found to reduce this effect. Whilst increased training experience has been found to enhance it. The study also found a protein intake greater than 1.6 grams per kg of body-weight combined with resistance training did not further contribute to lean muscle gains.

Despite this the study recommended it may be prudent to take a dosage of 2.2 grams per kg of body-weight to maximize gains in lean muscle tissue. It also stated older individuals have anabolic resistance. This means they will need higher amounts of protein to achieve similar rates of muscle protein synthesis of younger individuals in order to stimulate muscle tissue growth (2).

Other research recommends a daily dosage of between 1.4 and 2.0 grams of protein per kg of body-weight to maintain or gain muscle mass. It is advised these protein doses are evenly distributed, every 3 to 4 hours throughout the day.

The same research state a higher protein intake may be necessary for resistance trained individuals to maintain muscle. There is also an agreement the optimal protein intake to maximize muscle protein synthesis is dependent upon age and the amount of resistance training the individual has completed. Additionally, protein shakes are recommended to contain 700 to 3000 mg of leucine in addition to a balance of essential amino acids (3). Whey protein powder would be a suitable choice to achieve this.

Is It Better To Drink A Protein Shake Before Or After A Workout?

In scientific literature there are two main schools of thought when it comes to the best time to take protein powder. They are; timing is irrelevant, drinking a protein shake post workout is optimal and drinking protein pre workout is optimal. There is also the 'anabolic window theory'.

The Anabolic Window Theory

The anabolic window theory is based off the premise of the body being in an anabolic state after resistance training. This involves a range of cellular processes which aid muscle repair and trigger muscle growth. This is fuelled by protein and carbohydrates. The theory believes there is a small post workout time frame of approximately 30 minutes to fuel this anabolic response. It claims the consumption of protein and carbohydrates is vital for increasing protein synthesis, reducing muscle protein break down and replacing muscle glycogen. Although a popular theory, there is no conclusive scientific evidence to confirm it is true.

However a study stated, as it is not possible to determine the impact of nutrition on any individual muscle protein. It advises to optimise muscle protein synthesis post workout, until better method to prevent muscle protein breakdown are known (7).

The Time You Drink A Protein Shake Is Irrelevant

Research from “The International Society of Sports Nutrition” believe the best time to take protein depends on the individual and there are benefits from taking protein powder pre-or post-workout. It also states the anabolic effect of exercise last 24 hours. But is likely to diminish at a faster rate as time elapses from workout completion. The position they take on pre-or post-workout protein shake consumption is resistance exercise and protein ingestion stimulates protein synthesis. The combination of both is synergistic when protein is taken before or after resistance exercise (3)

Additional research supports the positive impact of protein supplementation on the lean body mass of adults regardless of whether it is consumed pre or post workout (4). Further studies refute the anabolic window theory. One states despite the apparent biological plausibility of the strategy adequate protein intake in combination with resistance exercise is the key factor in maximizing muscle protein synthesis. It goes on to mention if a peri-workout anabolic window does exist. This window would likely be greater than one hour either side of resistance training (5). Whilst another study found pre- and post-workout protein consumption had similar effects. It went on to state these findings rejected the contention of a narrow anabolic window (6).

Taking A Protein Shake Post Workout Is Optimal

Consuming protein after a workout helps stimulate muscle protein synthesis. This is important to inhibit muscle protein breakdown post exercise. Research has found the ingestion of approximately 20 grams of protein during or immediately after exercise is sufficient to maximise post exercise protein synthesis rates (8). Further research has state from a pragmatic standpoint taking a protein post exercise is an opportunity to consume nutrients. And despite scientific literature refuting claims of an anabolic window closing within an hour of training, there is no disadvantage from assuming there is an anabolic window. From a performance and recovery perspective it appears it is beneficial to follow the anabolic window philosophy until a better alternative is scientifically proven (9).

Taking A Protein Shake Pre Workout Is Optimal

One study stated the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. It also mentioned to build muscle and strength to maximum potential, a 10-12 week resistance training program containing upper and lower body compound movements should be followed (10).

Other studies suggest the ingestion of free amino acids and carbohydrates before exercise lead to superior anabolic response from the exercise compared to ingestion post-workout. However, it does go on to state the difference between protein ingestion pre-and post-exercise is not apparent (11).

What Is The Benefit Of Taking A Protein Shake Close To A Workout?

Protein powders are an easy, effective and quick way to get protein into your system. This is especially useful after a strenuous workout. Muscle protein anabolism is acutely elevated following resistance exercise. This can be further enhanced from the ingestion of protein. This makes protein shakes an effective nutritional strategy for restoring the acute loss of contractile function which occurs following strenuous exercise (12).

Taking protein powder before or after a workout is only 1 factor when it comes to achieving your goals.

Factors Other Than Protein Shake Timing

Whether you take a protein shake before or after  workout is not the most important factor in ensuring you reach your health, fitness and sporting goals. The 3 most important factors in determining your success are:

Overall Protein Intake

As mentioned earlier a daily protein intake of between 1.6 and 2.2 grams per kg of bodyweight is optimal if you are pursuing lean muscle gain.

For athletes, the recommended protein intake will vary depending upon the number of calories consumed. In situations where a calorie deficit is being maintained a daily protein intake as high at 1.8 to 2.0 grams per kg of bodyweight is recommended. The reason for this is to promote fat loss whilst preserving muscle. In times where there is not a calorie deficit a daily protein consumption of between 1.3 and 1.8 g per kg of bodyweight is recommended (13).

For weight loss it has been found higher-protein diets which contain a daily intake of protein between 1.2 and 1.6 grams per kg of bodyweight provide improvements in appetite and body weight management (14). This is also supported by the satiety improvements caused by consuming more protein.


Protein synthesis is stimulated by resistance exercise, then further enhanced by the ingestion of protein. Without this initial increase from resistance training your results will not be maximised. This is especially true when pursuing goals relating to retaining muscle, increasing strength and growing lean muscle tissue (15).

Resistance training is a crucial piece of the puzzle when pursuing most goals. It has been found protein synthesis is elevated by 50%, 4 hours after intense resistance training. Then by 109% 24 hours after the training. These levels don’t return to normal levels for 36 hours after training. These elevated levels for 36 hours after training can make a significant difference in the speed at which your goals are achieved (16).

It has been found the benefits of resistance training are far reaching beyond improved physical performance and muscle brains. Research has found these benefits include improve movement control, walking speed, functional independence, cognitive abilities, self-esteem and reduced visceral fat. It has also been found to reverse specific aging factors in skeletal muscle (17). This shows adding resistance training and increased protein intake (using protein shakes or dietary protein) into any training plan can help goals be achieved faster.

For fat loss, aerobic training, resistance training and a combination of the two have been found to be effective. The use of aerobic training and the combination of resistance with aerobic training proved to be the most effective way to reduce fat and bod-weight. Whereas resistance training alone and in combination with aerobic training being found to improve lean body mass the most.

The following protocol is recommended if you have time constraints; If reducing weight and fat is the primary objective aerobic training should be prioritised. And if reducing fat is the objective resistance training should be prioritised.

However, if there is time for both resistance and aerobic training they should be incorporated into your training program (18). No matter which type of training is used the use of protein powder will be beneficial. It will provide the body with the essential amino acids needed to support muscle recovery and build muscle tissue. Whilst stimulating protein synthesis and increasing satiety.

In fact, research has found although resistance training alone helps with the reduction of fat loss. The use of diet alone is superior. And when combined together fat loss results were maximized (19).

Protein Ingestion Timing, Quantity And Distribution

Research has found the timing and distribution of protein intake following resistance exercise has an impact on the anabolic response of skeletal muscle. 3 different protocols where analysed; 8 dosages of 10 grams of protein every 1.5 hours. 4 dosages of 20 grams of protein every 3 hours. And 2 dosages of 40 grams of protein every 6 hours. It was found 4 dosages of 20 grams of whey protein every 3 hours was the most effective protocol for stimulating protein synthesis throughout the day (20). This suggests this dosage would be optimal to maximise the results of resistance training. An example of implementing this protocol would be 20 grams of dietary protein in 3 meals and one 20-gram dose using a protein powder post workout.

Calorie Intake

A calorie deficit is the most important factor in weight loss (21). If a deficit is not maintained weight will not be lost. Extreme calorie deficits may not be beneficial for weight loss as they are very hard to maintain.  Thus, the best type of diet for weight management is one that can be maintained in the long term. A small calorie deficit over time will result in long term sustainable weight loss. Increasing protein intake can help with maintaining a calorie deficit as it helps improve satiety. This makes it less likely a diet will go into surplus due to binge eating.

To build muscle the creation of an energy surplus is often recommended by sports nutritionists. However, research states this is not conclusive as this recommendation is normally based off the assumed energy stored within the muscle tissue. This does not account for other energetically expensive processes and metabolic responses to an energy surplus. To gain muscle with subsequent fat gain a better understanding of these dynamics would be needed (22). The research paper goes on to advise a conservative surplus if muscle growth is the objective with an initial surplus of 1500 to 2000 calories per day. It also states changes in body composition should be monitored carefully and any necessary adjustments made.

Further research analysis competitive male bodybuilders has found greater energy intake in combination with resistance training induces greater increases in both muscle mass and body fat (23).

These findings suggest if body fat is not an issue more calories will result in maximum muscle gain but with the drawback of extra fat being accumulated. And if lean muscle gain is preferred calories should be added conservatively with the results carefully monitored.

For athletes who train in excess of 90 minutes per day research has found the following recommended energy intakes; 50 calories per kg of bodyweight  for males and 45 to 50 calories per kg of bodyweight for females (24). In order to keep weight body composition at ideal levels for sporting performance, weight and body-fat should be measured frequently. If any deviations from optimal weight or body-fat levels are noticed adjustments should be made.

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What Happens When You Drink A Protein Shake After A Workout?

Using protein shakes after your workout helps to enhance protein synthesis and provide the body with the essential amino acids to fuel muscle recovery and growth. Although this can be achieved with dietary protein, protein shakes offer a convenient way to provide the body with immediate protein post workout. This results in elevated blood amino acids which will be transported straight to the muscles.

The speed at which this protein is released will depend if the protein powder used is fast or slow releasing. Whey protein is a n example of a fast releasing protein and casein protein is an example of a slow releasing protein. If post workout recovery is your primary concern a fast releasing protein will be better. However, if you are on a diet and trying to stay feeling full to maintain a calorie deficit taking a slow releasing protein shake such as casein protein may give you better results.

Can You Eat Food With A Protein Shake After A Workout?

You can eat a meal or snack alongside your post workout protein shake. People often do this if they workout on an empty stomach. It has become a regular regime for many people who do intermittent fasting or workouts focusing on burning fat.

If you train without eating, you will most likely be starving post-workout. The reason for this is because you burn all of your energy reserves during your workout. This would be an example where eating your first meal with a protein shake would be beneficial.

You probably shouldn't eat a meal and protein shake before a workout session because it can get too heavy on your digestive system and make you feel ill. A small snack like an energy bar might be fine, but anything more too close to a gym session will leave you feeling bloated and can even slow down your training and cause nausea.

Consult a health practitioner or nutritionist before starting any supplementation to determine what works best for your body type, needs, and goals, especially if you have any underlying health concerns.

When Is The Best Time To Drink A Protein Shake?

Despite conflicting scientific literature regarding whether you should drink a protein shake pre or post workout. The available evidence suggests post workout would be the most beneficial time to take a protein shake. The reason for this is despite some research rejecting the anabolic window theory, no disadvantage is given to taking a protein shake immediately after a workout. It is agreed protein ingestion is beneficial for muscle protein synthesis which means a post workout protein shake will give you this benefit whilst covering you if the anabolic window theory is true. However, whether you decide on a pre or post workout shake the impact on your results is likely to be minimal.

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