You chug them down after every workout like your life depends on it, but do you really know if protein shakes do anything? There are scientific studies covering various topics such as the best time to take them, the best type to use, and why they may or may not benefit you.
Supplement companies can often make things confusing with bold claims solely for marketing purposes. The market value of protein supplements alone is worth over USD 12.4 billion. This article aims to cover your most common questions and the most important information you should know. Feel free to skip over the points that don’t apply to you.
1. Why Should You Care About Protein?
Making sure you’re getting adequate levels of protein in your diet will accelerate your progress, enhance your recovery, and have a positive impact on your overall health and longevity.
Just a few critical functions of protein include:
- Providing a structural component to bodily tissues and cells.
- Providing a source of nitrogen. Nitrogen balance is the key to gaining lean muscle mass and preventing muscle breakdown when losing body fat.
- Cell signaling for various biochemical processes, including muscle growth and fat loss.
- Gluconeogenesis and forming glucose for energy when carbohydrates are restricted.
- To help maintain and optimize key hormones.
2. How Does Protein Benefit Muscle Growth?
Whether you’re looking to get bigger, stronger, leaner, or recover faster, enough protein can help optimize adaptations to training.
Protein works in the body to provide benefits such as:
- Increased muscle mass.
- Prevention of muscle breakdown and promotion of muscle recovery.
- Increase your ability to lose body fat and stick to a diet plan due to its satiating effect.
- Besides the effects on body composition, it will also improve the overall health of your body, such as better skin, stronger nails and hair, and a better immune system.
3. How Much Protein Should You Have in Your Diet?
If you’re training hard 1.6-2g of protein per kilogram of bodyweight is a good starting point. So someone weighing 75kg (165lbs) should have a maximum of 150g of protein per day.
Various studies have been quoted as recommending several daily protein targets:
- In a thorough review, Wilson & Wilson recommend 1.2-2.2g per kilogram of total body weight for strength training athletes.
- Helms et al. recommended 2.3-3.1g of protein per kilogram of fat-free mass (lean mass) in lean resistance-trained athletes under hypocaloric conditions (i.e. using low-calorie diets).
- The ACSM position stand suggests 1.2-2g per kilogram per day to support muscle repair, remodeling, and adaptation. While the upper limit of 2g/kg/day might be better when retaining muscle mass during times of calorie restriction.
- In a meta-analysis of 49 studies, Morton et al. showed no significant effects on fat-free mass above 1.6g/kg/day.
If you require a macronutrients calculator you can find one here.
4. What Factors Effect How Much Protein Is Needed?
This is just one example of how a diet needs to be individualized according to your training, goals, and even genetics.
Some of the main factors that affect how much protein you should have included:
- Are you surviving or are you thriving? If you want to optimize training adaptations and thrive then your protein intake should be higher than a typical government recommended RDA. During intense periods of training or dieting protein intake should make up a slightly higher proportion of your total calorie intake, whereas, during maintenance phases of training, intake should be closer to the lower end of what’s recommended.
- If you are eating lower calories to drop body fat, contrary to belief you should consume a higher percentage of total calories as protein versus if you were in a calorie surplus. This helps to preserve lean muscle mass and allows more freedom to drop carbohydrate and fat intake.
- Endurance athletes should strive to stay at a low bodyweight so as their power to bodyweight ratio is maximized, and their movement economy is improved. A lower protein intake might be considered to limit gains in lean body mass.
- There have even been some suggestions that genetics affect your protein needs. The closer to the equator you can trace your genetics from, the less protein you will need while being able to “tolerate” more carbohydrates. The further away you are from the equator the more protein you may have in your diet.
- Since both carbohydrates and protein have similar nitrogen sparring effects, if you consume a lower carbohydrate diet it should be advised that your protein intake be higher to help compensate.
- The older you are the less protein you need. Studies in the elderly show minimal effects of a high protein diet on strength and muscle mass.
- If your current levels of muscle mass are higher, then an increased dosage of protein is recommended throughout the day. Helms et al. suggest 2.3-3.1g of protein per kilogram based on your lean mass and not total body weight.
5. Is a Higher Protein Intake Safe?
Yes, but there are some exceptions.
Higher levels of protein consumption are safe in most, however, consider whether you have a family history, or have ever suffered from kidney issues. A review of past research by showed those with existing kidney disease should restrict protein intake, although for those with no preexisting conditions a high protein intake does not affect kidney function.
If you have a family history the best advice it to always seek the advice of a qualified medical professional before undertaking a high protein diet.
6. How Does Protein Consumption Relate to Resistance Training?
Not what you think, or what you may have been told. Remember, train to stimulate, not annihilate!
- Before training: If nutrition and training are correct the body will be in a positive net protein balance; synthesis will be greater than breakdown.
- During training: The body will be in a negative net protein balance. Tissue breakdown contrary to popular belief stays the same during training, however, the synthesis of new proteins drops. Breakdown eventually exceeds synthesis as the duration of training goes on. The body is constantly breaking down and repairing at the same time. To gain muscle mass you want the repair to be happening at a faster rate than the breakdown. The longer your workouts, the longer it takes you to get the muscle building stimulus you need the more unnecessary breakdown will occur.
- Post training: For a short while net protein balance will remain negative, mostly because your body has stopped synthesizing new proteins. Breakdown slightly increases at this point but in the hours to come protein synthesis rapidly rises to exceed breakdown, and to a level that exceeds pre-training. This is where adaptations are made and where it’s essential that your body is provided with the right nutrients in order to assist in tissue repair.
7. Do Post-Workout Protein Shakes Work?
Yes, here’s why.
During a workout, your body will be in a negative net protein balance. As building of new proteins grinds to a halt, protein breakdown increases. After training muscle protein synthesis eventually increases and breakdown reduces, creating a positive nitrogen balance. That’s just basic science, and we understand this mechanism in the most part.
Using protein and supplying your body with the amino acids that it needs around these key times is vital in helping to increase muscle protein synthesis as well as decrease protein breakdown. Because of this, a higher net protein balance can be achieved which helps to promote gains in lean muscle mass, strength, and muscle recovery.
Ingesting amino acids or whey protein in the post-workout period has typically been shown to produce a twofold increase in muscle protein synthesis and other factors that contribute to muscle gain.
Of note, carbohydrates alone without protein typically result in half the response of whey protein or essential amino acids. So, although carbohydrates are important, in order to build muscle size and strength, supplying your body with protein is twice as important.
8. When Should I Drink My Post-Workout Protein Shake?
The truth is nobody knows if there is perfect timing for post-workout shake consumption. Some researchers have put forth the notion that timing of post-workout protein intake may be superior to absolute daily protein intake. You could then assume that the timing of protein intake around your workout achieves a greater effect than when consumed any other time of day when total daily protein intake is the same.
It has been suggested that adequate protein intake in the post-workout window is vital for optimizing muscle protein synthesis, protein breakdown, creating a positive net protein balance, and stimulating training adaptations.
For these essential mechanisms to be activated, several chemical processes need to take place, and hormonal secretion plays a vital role. Both increased amino acid availability (hyperaminoacidemia) and insulin secretion (hyperinsulinemia) are important for maximizing the anabolic and recovery potential of muscle.
Some studies have shown there to be a post-workout anabolic window, however, others have not. In a 2016 meta-analysis, Schoenfeld et al. showed no effect of timing protein intake for strength or hypertrophy adaptations.
The duration of this post-workout window has also shown to be varied (if it even exists), and while some have shown 15-30 minutes as optimal, some have shown the window to last as long as two hours or more.
Based on what we do know, it may be suggested that although protein shakes can be a great tool post-workout, it would make no big difference whether you were to have it immediately post-workout or an hour afterward. Total daily protein intake should be your priority, followed by timing.
9. How Much Protein Should I Have in My Post-Workout Shake?
If you have carbohydrates post-workout then plan to have at least 25g of protein with 50g of carbohydrate. If you are choosing not to consume carbohydrates, then 50g of protein should do the job. For specific targets, 0.48g per kg of body weight has been suggested, meaning an 80kg individual would consume 38g of whey protein post-workout.
In order to increase both hyperinsulinemia and hyperaminoacidemia in the post-workout period, a mixture of both “fast” acting proteins and high glycemic carbohydrate is recommended. Some of the most conclusive evidence suggests that a 2/1 to 3/1 ratio of carbohydrate to protein is most effective for recovery, using anywhere between 20-30g of protein with 40-90g carbohydrate.
However, if restricting carbohydrates in order to “spike” insulin levels to the same degree having 50g of fast-acting protein can achieve near the same effect. The most important part is that you consider whether carbohydrates fit within your current approach and factor this into your daily totals.
10. Should I have a Protein Shake Before My Workout?
It could help!
Increased levels of amino acids within the blood from ingestion of amino acids before or during exercise, as opposed to after exercise, may counter the net loss of muscle protein that happens during a workout.
Amino acids before a workout may cause less tissue breakdown and hence create a more anabolic environment. Therefore, a combination of amino acids via a protein or amino acid supplement, such as essential amino acids (EAA), can be consumed in order to increase amino acid availability. Schoenfeld et al. showed pre versus post-workout protein intake to potentially have a similar effect on muscular adaptations.
11. How Long Before My Workout Should I Have a Protein Shake?
Having your protein shake 30 minutes beforehand should allow some of those amino acids to be floating around in your bloodstream by the time you begin your workout if the right protein sources are ingested. Therefore, an EAA or a hydrolyzed protein drink may be best when consumed pre-workout.
12. What Type of Protein Is Best Post-Workout?
Whey protein is the most research-proven and can commonly be found in three main forms:
- Whey concentrate: This form of protein typically contains the lowest percentage of protein per 100g. This is due to concentrate undergoing less processing to produce the product. A good quality whey concentrate should contain 75% protein per serving. Several bioactive fractions of whey concentrate contribute to its immune boosting potential including beta-lactoglobulin, alpha-lactalbumin, glycomacropeptide, and lactoferrin. Whey concentrate has also been shown to increase the body’s production of glutathione, an extremely potent antioxidant sometimes referred to as the body’s master antioxidant.
- Whey isolate: Contains a larger percentage of protein per serving. It’s produced when whey concentrate is further processed and purified using techniques such as crossflow micro-filtration, ultra-filtration, reverse osmosis, or nano-filtration. The rate of absorption is typically about the same between concentrate and isolate, however, isolate may be the best choice if you want the highest amount of protein per serving.
- Whey hydrolysate: This is whey isolate that has been further broken down, producing smaller peptides that are rapidly absorbed into the bloodstream.
It’s important to note that although some would consider whey concentrate to be the lowest quality of protein versus isolate and hydrolysate. Due to its protein content alone, whey concentrate contains some potent immune boosting properties you might want to consider.
13. What If I Can’t Use Whey?
As an alternative, brown rice protein, pea protein, or hemp protein are good choices if whey isn’t an option.
There are limited studies using plant-based proteins on muscular recovery and adaptations. This is largely because these are a newer trend, but also they don’t have as favorable amino acid profile as whey.
Total protein content of some of these can come close to a whey concentrate, but it is the EAA and branched-chain amino acid (BCAA) profile that are of most importance. Brown rice protein may be one of the best alternatives to whey, but a whey isolate can have a 39% greater EAA content and 33% greater BCAA content.
They are also typically lower in the amino acid leucine, which has been shown independently of other amino acids to activate key signaling pathways associated with muscle protein synthesis. A protein meal should contain approximately 4g of leucine to hit the required leucine “threshold,” something that it much harder to achieve with plant-based proteins.
14. Should I Use a Protein Supplement Before Bed?
In reality, it’s not essential but it could aid muscle recovery.
For most people, overnight sleep is your longest period of fasting and what we refer to as the post-absorptive phase. Overnight, muscle protein synthesis drops while muscle protein breakdown elevates, leading to a more catabolic state.
Muscle tissue breakdown is used to “feed” the tissues of the gut, liver, intestines, and other organs around the splanchnic region, so a slow digesting form of protein and a steady stream of amino acids throughout the night may, therefore, help reduce muscle catabolism.
15. Can My Post-Workout Protein Be Used Before Bed?
What works the best post-workout will probably work the worst before bed.
After around 1 hour of having a whey protein shake the blood amino acid levels are elevated by about 300%, after 2 hours drop to about 92%, and after 4 hours you’re back to baseline. This is great for that post-workout window but not so good for an overnight fast. On the other hand, casein produces a moderate but prolonged spike in blood amino acid levels for around 4-5 hours before there’s a drop-off.
Res et al. showed that casein protein 30 minutes before bed was able to be digested and absorbed by the body, allowing for greater muscle recovery and overnight adaptations to take place. Casein protein can clot in the stomach allowing a steady “drip feed” of amino acids throughout the night.
Studies have shown the addition of a small amount of whey protein to the casein, such as in a milk protein blend or timed-release protein, could drip feed the muscles for a greater time than casein alone, potentially up to 8 hours, and even help to improve sleep quality.
This could potentially be due to the different ways in which casein and whey work, and likely they have a synergistic effect when taken together. Whey protein has also been shown to enhance sleep quality and next-day alertness.
The take-home point here is that 30 to 40g of protein 30-60 minutes before bed or as a late evening snack, depending on preference, should be considered good practice when trying to build muscle and strength. If eating this close to bed affects your sleep quality, then try having your shake two hours before bed instead.
Put Protein to Work
Your total daily protein intake is more important than your post-workout protein timing. Protein shakes have been shown to be effective both pre and post-workout, but if a specific “window” of opportunity exists remains unclear.
A slower release protein shake or wholefood protein source may also be beneficial before bed. It would be reasonable to suggest that although protein shakes aren’t essential, they are at least a convenient and cost-effective way to help you hit your total daily protein intake.