Protein shakes have long been a staple in the fitness and bodybuilding communities, lauded for their muscle-building prowess.

While they’re principally used and promoted as a post-workout recovery tool, that doesn’t mean this is the only time you should take them.

In fact, the whole idea of the “post-workout window” has come under scrutiny.

This leads to the question, should you drink protein shakes even on your rest days?

The debate has been ongoing, with some arguing that protein shakes are only necessary on workout days to aid in muscle recovery and growth. However, we’re here to take a firm stance: YES, you should absolutely drink protein shakes on your rest days.

And we’re not just saying this off the cuff; we have science-backed reasons to support this claim.

The Importance of Protein

Protein isn’t just the buzzword of bodybuilders; it’s the building block of life itself. There are some theories that life began by the correct composition of amino acids, proteins, extreme heat, and atmospheric gas.

While this is a theory, we do know that protein is among the three macronutrients and plays a pivotal role in muscle repair and growth.

When you work out, you’re essentially tearing your muscle fibers, and it’s protein that swoops in to repair these tears, making your muscles stronger and more resilient. This process is known as muscle protein synthesis, and it’s the golden ticket to gains, strength, and overall physical well-being.

But here’s the kicker: most people are falling short in the protein department. According to various studies, the average adult doesn’t meet their daily protein needs, especially if they’re physically active. [1]

The Recommended Dietary Allowance (RDA) for protein is about 0.8 grams per kilogram (or 0.36 grams per pound of body weight) for sedentary adults. But if you’re active or aiming for specific fitness goals, you may need up to 2 grams per kilogram.

That’s a lot of chicken breasts and lentils, my friends. And let’s be real, who has the time or stomach space to consume that much food every day? This is where protein shakes come in handy, offering a convenient and efficient way to meet your protein needs, even on rest days.

The Under-discussed Aging Factor

Aging is inevitable, but becoming frail doesn’t have to be. As we age, we often lose muscle mass and strength—a condition known as sarcopenia [2]. This isn’t just an aesthetic issue; it’s a health concern. Reduced muscle mass increases the risk of falls, fractures, and a general decline in quality of life. It can even lead to more severe health issues like osteoporosis and cardiovascular diseases. [3]

The good news? Adequate protein intake can mitigate these effects. Protein isn’t just for the young gym-goers; it’s crucial for older adults who want to maintain their muscle mass and strength. Studies have shown that higher protein intake can help offset the muscle loss that comes with aging, especially when combined with resistance training. [4]

Now, you might be thinking, “I’m too old to be chowing down on steaks all day.” And you’re probably right. But that’s where protein shakes come into play. They offer a convenient, digestible, and efficient way to get high-quality protein without the hassle of preparing and eating large meals. Plus, many protein shakes come with added nutrients like vitamins and minerals, making them a well-rounded option for those looking to preserve muscle mass and strength as they age.

If you’re interested in exploring different types of protein shakes, you can check out blogs on the best plant-based protein powders or lactose-free protein powders to tailor your protein intake to your specific dietary preferences and needs.

The Science Behind Protein Intake on Rest Days

When it comes to muscle growth and repair, it’s a 24/7 job for your body. Contrary to popular belief, your muscles aren’t just growing during or immediately after a workout; they’re constantly in a state of turnover. This means that protein synthesis (building up) and protein degradation (breaking down) are ongoing processes that happen every day—yes, even on your non-workout days.

You don’t build muscle in the gym, you build it when you’re recovering from the gym.

So, there’s this study I found in the Journal of Sports Medicine from 2015. It’s pretty interesting because it suggests that protein supplementation can really help boost muscle mass and performance – but there’s a catch. It works best when your training routine is on point, meaning you’ve got the right frequency, volume, and duration. What’s cool is that it shows the importance of keeping up with your protein intake even on rest days. This way, you’re more likely to maintain and grow those muscles, even when you’re not hitting the gym. [5]

So, the science is clear: your body needs a steady supply of protein to support muscle growth and repair, and this doesn’t take a day off just because you do. By incorporating protein supplements into your diet on rest days, you’re giving your body the building blocks it needs to recover, grow, and prepare for your next workout. It’s not just about muscle repair; it’s about maintaining lean muscle and optimizing your weight loss journey.

How Much Protein Do You Need?

The amount of protein you need can vary based on several factors, including your age, sex, health status, and level of physical activity. However, general guidelines do exist to give us a starting point. As I mentioned, the Recommended Dietary Allowance (RDA) for protein is about 0.8 grams per kilogram of body weight for sedentary adults. But if you’re active or aiming for muscle growth, this number can jump up significantly.

On training days, some studies recommend between 1 to 1.6 grams of protein per kilogram of body weight, depending on the intensity and type of your workout. This ensures that you’re providing your muscles with enough raw material for repair and growth. [6]

The Post-Workout Window Myth

Now, let’s address the “post-workout window” myth. The idea that you must consume protein within a specific time frame post-workout for optimal muscle repair has been largely debunked. Research shows that muscle protein synthesis can actually peak up to 48 hours post-workout. This means that your protein needs on rest days are not drastically different from training days. [7]

Therefore, aiming for at least 1.2 grams per kilogram of body weight is a good rule of thumb for rest days as well. Why keep protein intake high on rest days? Because muscle recovery isn’t a switch that you turn on and off. It’s a continuous process that requires consistent nourishment. By maintaining a steady intake of protein, you’re ensuring that your body has what it needs to repair and build muscle, even when you’re not actively stressing them in the gym.

So, whether it’s a training day or a rest day, skimping on protein supplements is not an option if you’re serious about your health and performance. Protein supplements can be a convenient and effective way to meet these needs, especially when whole-food options are not readily available.

Protein Shakes vs. Whole Foods

Adding protein powder to shaker bottle

When it comes to meeting your protein needs, both protein supplements and whole foods have their merits. Let’s break it down:

Protein Shake Benefits

A. Explanation of Protein Supplements and Their Benefits:

Protein supplements are a quick and efficient way to get a concentrated dose of high-quality protein. They’re often made from whey, casein, or plant-based proteins like pea or hemp.

B. Convenience:

One of the biggest advantages of protein supplements is their convenience. You can easily carry a protein supplement in your bag and drink it on the go, making it easier to meet your protein requirements if you have a low protein diet throughout the day.

C. Muscle Recovery:

Protein supplements are often formulated with additional nutrients and amino acids that can aid in muscle recovery. This makes them a popular choice for post-workout nutrition.

D. Meeting Protein Needs:

For those who struggle to meet their protein needs through whole foods alone—perhaps due to a busy lifestyle or dietary restrictions—protein supplements can be a valuable addition to their nutrition plan.

Protein Shake Drawbacks

A. Potential Drawbacks:

While protein supplements are convenient, they can also be expensive per serving compared to whole food protein sources like chicken. Although this depends. Overall, the cost is usually not drastically different.

B. Negative Effects:

Some protein supplements may contain added sugars, artificial sweeteners, or other additives that you might want to avoid.

C. Impact on Overall Nutrition:

Relying too heavily on protein supplements can also mean missing out on the other nutrients that whole foods provide, such as fiber, vitamins, and minerals.

Protein supplements are a handy and quick way to boost your protein intake, whether you’re in a rush or just finished a workout. But it’s essential to remember that they shouldn’t be your sole source of nutrition. The best approach is a balanced one – mixing protein supplements with a diverse range of whole foods. This combo ensures you get a wide array of nutrients, contributing to both your overall health and performance.

Why Do Rest Days Matter?

The Concept of Muscle Recovery

Rest days are not just about giving yourself a break from the gym; they’re an integral part of the muscle-building and recovery process. When you work out, you’re essentially creating micro-tears in your muscle fibers. These tears are a good thing—they signal the body to rebuild and repair, leading to stronger, more resilient muscles. However, this repair process doesn’t happen during the workout; it happens during the rest periods between workouts. [8]

The Role of Protein on Rest Days

You might think that because you’re not actively exercising, your protein needs decrease on rest days. That’s a common misconception. In reality, your body is still hard at work repairing and rebuilding muscle tissue, and it needs protein to do so effectively. Protein provides the essential amino acids that act as the building blocks for this repair process.

In fact, consuming high protein on rest days can be just as important, if not more so, than on training days. This is because the muscle repair process can continue for 24-48 hours post-exercise, depending on the intensity and duration of the workout. Therefore, skimping on protein on your rest days can actually hinder your recovery and muscle growth. [7]

The Benefits of High Protein Intake on Rest Days

High Protein Intake on Rest Days: A Key to Lean Muscle Preservation

So, we know that protein is crucial for muscle recovery and growth. But what about those precious rest days when you’re not pushing yourself at the gym or with intense workouts? Do protein supplements still have a role to play on these days? The answer is a resounding yes.

Maximizing Lean Muscle Gains

It’s easy to fall into the trap of cutting back on your protein intake during rest days, thinking that you only need it when you’re in the midst of an active workout. But here’s the deal: that’s a pretty common misconception. Your muscles aren’t on the same calendar as your rest days. They’re always working, repairing, and growing, whether you’re sweating it out in the gym or not.

Keeping up with a high protein intake on your rest days is a smart move to ensure your body has the essential building blocks for muscle recovery. It’s not just about patching up the little muscle tears from your workouts; it’s also about safeguarding your lean muscle mass, especially if you’re on a weight loss journey. When you opt for protein supplements on your rest days, you’re basically giving your body the amino acids it needs to keep up its muscle maintenance work.

Carbohydrates and Protein Supplements: A Winning Combination

Protein supplements are a great way to amp up your protein intake on rest days, but it’s essential to remember that a balanced approach is the key. Carbs, sometimes unjustly criticized in certain dieting trends, have their own important role to play. When you combine carbohydrates with protein, it can actually boost the use of amino acids for muscle repair and recovery.

So, when you’re on your rest days, think about adding protein supplements to your routine along with a balanced dose of carbohydrates. This combination can really turbocharge your muscle recovery and help you stay on track with your fitness goals.

Some of the Common Myths Debunked

Myth 1: Protein Shakes Are Only for Workout Days

One of the most pervasive myths is that protein supplements are only necessary on days when you’re hitting the gym. As we’ve already discussed, your muscles are in a constant state of repair and growth, even on rest days. Protein supplements can provide a quick and convenient source of high-quality protein that aids in this recovery process.

Myth 2: Too Much Protein Is Harmful

Another common misconception is that consuming too much protein can lead to kidney damage or other health issues. While it’s true that excessive protein intake can be harmful for individuals with pre-existing kidney conditions, for the average healthy adult, higher protein intake within a balanced diet is generally safe and can be beneficial for muscle growth and recovery.

This study in the Journal of Nutrition and Metabolism from 2016 looked at resistance-trained men who followed a high-protein diet for a whole year. The study found that this diet didn’t mess with their blood lipids, liver, or kidney function – all these crucial health markers stayed in the clear. Despite eating more calories while on the high-protein diet, these guys didn’t pack on extra fat. So, it looks like for these fellas, going high on protein didn’t harm their health and didn’t lead to a fat gain either. [9]

Myth 3: Protein Shakes Make You Gain Unwanted Weight

Some people fear that drinking protein supplements on rest days will lead to weight gain. However, protein supplements, when incorporated into a balanced diet, do not inherently cause weight gain. In fact, protein has a higher thermic effect than carbohydrates or fats, meaning your body uses more energy to digest it, which can aid in weight management. [9]

Myth 4: Plant-Based Protein Is Inferior to Whey Protein

Whey protein is a complete protein source, containing substantial quantities of BCAAs (branched-chain amino acids) that actively promote muscle protein synthesis. Plant-based proteins like pea or hemp can also provide all the essential amino acids when combined correctly. They are a viable option for vegetarians, vegans, or those with dairy allergies and can be just as effective for muscle recovery. Read more about the best plant based protein powders here.

Myth 5: The “Anabolic Window” Is Crucial for Protein Intake

The idea that there’s a narrow “anabolic window” post-workout during which you must consume protein has been largely debunked. Protein synthesis occurs over a longer period, and consuming protein before or several hours after a workout can still contribute to muscle growth and repair.

By dispelling these myths, we can make more informed choices about our high protein intake, optimizing our muscle growth and recovery, whether it’s a workout day or a rest day.


Should you take protein shakes when you’re not working out?

Yes, protein shakes can be beneficial even on rest days. Your muscles are in a constant state of repair and growth, and a steady intake of high protein can aid in this process. Protein shakes offer a convenient and efficient way to meet your protein needs.

How often should you drink protein shakes?

The frequency of protein shake consumption depends on your individual protein needs, which can vary based on factors like age, activity level, and specific fitness goals. However, it’s generally a good idea to spread your protein intake evenly throughout the day to maximize muscle protein synthesis.

Do protein shakes help with muscle recovery?

Yes, protein shakes can significantly aid in muscle recovery. They provide a quick source of high-quality protein that can accelerate the repair and growth of muscle fibers, thereby enhancing recovery and reducing muscle soreness.

Does muscle soreness mean not enough protein?

Not necessarily. While inadequate protein intake can impair muscle recovery, soreness is often a result of micro-tears in the muscle fibers during intense exercise. It’s a natural part of the muscle-building process. However, adequate protein can help mitigate the extent of soreness and speed up the recovery process.

What else helps speed up muscle recovery?

In addition to adequate protein intake, other factors like proper hydration, sufficient sleep, and the inclusion of anti-inflammatory foods in your diet can aid in muscle recovery. Active recovery techniques such as stretching, foam rolling, and light aerobic exercise can also be beneficial.

Can I take TWO protein powder shakes on rest days?

While there’s nothing wrong with this in a pinch, in general, your goal should be to get most of your protein from a well-balanced diet with whole foods. However, if your protein needs are high and it’s challenging to meet them through whole foods alone, adding an extra protein shake on rest days can be a practical solution. Just ensure it fits into your overall dietary plan and doesn’t lead to excessive calorie intake.

Bottom Line

So there you have it, the protein shake verdict is in, and it’s a resounding YES for rest days. Whether you’re crushing it at the gym or indulging in some well-deserved downtime, high protein intake remains a key player in your fitness journey.

But remember, it’s not just about bulking up. Protein is the ultimate architect behind the scenes, tirelessly working to repair and maintain your muscles. It’s the silent hero that keeps you strong, no matter your age or fitness goals.

And let’s debunk those myths while we’re at it. Protein shakes aren’t just for workout days – your muscles don’t punch a timecard. They’re always in construction mode, whether you’re lifting weights or lifting your remote control.

And the idea that protein shakes will pack on unwanted pounds? That’s not the whole story. When incorporated into a balanced diet, protein can actually help you manage your weight better.

So, take those protein shakes, keep your muscles fueled, and don’t forget to mix in some carbs for an added boost. Whether you’re aiming for gains or just preserving the muscle you’ve got, protein supplements on rest days are your secret weapon.

Remember, it’s not just about the numbers on the scale. It’s about how you feel, how you move, and how you show up in the world. So keep sipping those protein shakes, nourish your body, and get ready to conquer your fitness journey, one rest day at a time.


1. Wu G. Dietary protein intake and human health. Food Funct. 2016 Mar;7(3):1251-65. doi: 10.1039/c5fo01530h. PMID: 26797090.

2. Ardeljan AD, Hurezeanu R. Sarcopenia. 2023 Jul 4. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 32809648.

3. Yu X, Sun S, Zhang S, Hao Q, Zhu B, Teng Y, Long Q, Li S, Lv Y, Yue Q, Lu S, Teng Z. A pooled analysis of the association between sarcopenia and osteoporosis. Medicine (Baltimore). 2022 Nov 18;101(46):e31692. doi: 10.1097/MD.0000000000031692. PMID: 36401390; PMCID: PMC9678526.

4. Paddon-Jones D, Rasmussen BB. Dietary protein recommendations and the prevention of sarcopenia. Curr Opin Clin Nutr Metab Care. 2009 Jan;12(1):86-90. doi: 10.1097/MCO.0b013e32831cef8b. PMID: 19057193; PMCID: PMC2760315.

5. Pasiakos SM, McLellan TM, Lieberman HR. The effects of protein supplements on muscle mass, strength, and aerobic and anaerobic power in healthy adults: a systematic review. Sports Med. 2015 Jan;45(1):111-31. doi: 10.1007/s40279-014-0242-2. PMID: 25169440.

6. Wu G. Dietary protein intake and human health. Food Funct. 2016 Mar;7(3):1251-65. doi: 10.1039/c5fo01530h. PMID: 26797090.

7. Phillips SM, Tipton KD, Aarsland A, Wolf SE, Wolfe RR. Mixed muscle protein synthesis and breakdown after resistance exercise in humans. Am J Physiol. 1997 Jul;273(1 Pt 1):E99-107. doi: 10.1152/ajpendo.1997.273.1.E99. PMID: 9252485.

8. Schoenfeld BJ. Does exercise-induced muscle damage play a role in skeletal muscle hypertrophy? J Strength Cond Res. 2012 May;26(5):1441-53. doi: 10.1519/JSC.0b013e31824f207e. PMID: 22344059.

9. Antonio J, Ellerbroek A, Silver T, Vargas L, Tamayo A, Buehn R, Peacock CA. A High Protein Diet Has No Harmful Effects: A One-Year Crossover Study in Resistance-Trained Males. J Nutr Metab. 2016;2016:9104792. doi: 10.1155/2016/9104792. Epub 2016 Oct 11. PMID: 27807480; PMCID: PMC5078648.

About the Author

David is a writer and strength coach and co-owner of Roman Fitness Systems. In addition to helping run RFS, he’s also the head editor for, the official website of the Strength and Conditioning Association of Professional Hockey. You can also check out his Instagram, he’s pretty easy on the eyes.

Source link


Please enter your comment!
Please enter your name here