Should You Drink Protein Shakes on Rest Days?

Nutrition plays a critical role in health and fitness. Protein, in particular, gives your body the building blocks it needs, whether you’re looking to build muscle or stay fit and healthy.

Gulping down a protein shake after a tough workout is a convenient way to give your body that building material. But should you drink protein shakes on rest days, too?

In this article, you’ll learn the importance of protein for reaching your fitness goals, whether you’ve hit the gym that day or not. 

Can You Drink Protein Shakes on Rest Days?

The short answer is yes, you can definitely drink protein shakes on days you’re not working out.

should you drink protein shakes on rest days: gulping down a shake

It is essential to consume enough protein on both training days and rest days. Protein is vital for muscle recovery and repair, and your body needs it just as much on rest days as it does on workout days.

However, if you are already getting enough protein from your diet from whole foods, there is no need to supplement with protein shakes on rest days. 

That doesn’t mean that it’s a bad idea to use a protein powder to boost your daily protein intake on off days. On the contrary, there are times when a shake is ideal, like when you’re in a hurry and don’t have time to sit down for a meal.

What Is Protein?

Protein is an essential nutrient that helps your body build and repair tissues like your muscles, skin, and organs. Think of it like a construction worker in your body, fixing and maintaining things.

Protein also supports other functions in your body, like hormone production and immune function.

You can find protein in foods like meat, fish, eggs, and beans or supplements like protein powder.

After you eat, your body breaks down the protein into amino acids. Just like you build different things with different Lego blocks, your body uses amino acids to do various jobs, including making your muscle fibers grow bigger and stronger.

should you drink protein shakes on rest days: protein

For anyone with an active lifestyle, protein plays a vital role in your muscle health, energy levels, and performance and is key whether your goals include fat loss or muscle gain.

Read more:

>> Protein for Strength Training: The Ultimate Guide

How Much Protein Do You Need Every Day?

Both in the US and Europe, general recommendations say that you need around 0.8 grams of protein per kilogram (0.36 grams per pound) of body weight each day. Some experts think that number is too low, but in general, it’s enough to maintain good health for the average person.

However, it’s not enough for fitness enthusiasts or athletes who want to see good results from their training. That little protein will make muscle gain slow going.

  • The American College of Sports Medicine recommends 1.2–1.7 grams of protein per kilogram of body weight (0.5–0.8 grams per pound) per day to increase muscle mass or if you engage in strenuous aerobic training.1
  • The International Society of Sports Nutrition goes even further and suggests that strength athletes and those who want to build muscle should aim for at least 1.4–2.0 g protein/kg (0.65–0.91 grams per pound) body weight/day.2

In short, physically active individuals need a higher protein diet than the average guy – more than twice more in some cases.

Eating that much protein from whole foods can be challenging, and getting some of it from a shake or two can help you reach your protein goals without stuffing yourself.

Best Protein Sources for Muscle Gain

Here is a list of protein sources loosely ranked for muscle-building potential:

  • Milk and dairy products (milk, yogurt, cheese, cottage cheese, greek yogurt, quark, casein- and whey protein powder)
  • Eggs
  • Red meat (beef, pork, lamb, game, ostrich, and other lean meats)
  • White meat (chicken, turkey)
  • Fish and seafood
  • Soy-based foods (tofu, tempeh, edamame, soy protein powder)
  • Quinoa
  • Beans, lentils
  • Nuts, almonds, seeds
  • Whole grains

Protein powder can be made from most of the foods in the list above, making them very versatile and diverse for meeting your protein needs.

What Are Protein Shakes and What Do They Do?

Protein shakes are concentrated sources of protein like whey, casein, egg, or soy. They either come pre-packaged and ready to drink or in the form of protein powder you mix in water, juice, milk, or another beverage of your choice.

should you drink protein shakes on rest days: protein powder

The protein you get from a shake performs the same functions as any other dietary protein: it builds and repairs almost everything in your body.

Protein shakes are no better or worse for muscle growth than other high-quality protein sources, even if the ads for protein supplements sometimes suggest that they have almost magical properties.

The benefits of protein supplements lie in their convenience and in helping you meet your daily protein needs.

Are Protein Shakes a Good Source of Protein on Non-Workout Days?

If you are serious about your training, your nutrition must be on point every day, whether you hit the gym or take a day off for rest and recovery.

Your muscles don’t grow while you train but in the hours and days after you leave the weight room. Your muscle tissue is extra sensitive to protein for 24 hours or more after a training session. That means your daily protein requirements are as high on recovery days as on training days.

Do you need one or more shakes to get the necessary protein on rest days? Nope. But they can be a great way to boost muscle protein synthesis and reach your protein target any day of the week.

What Are the Benefits of Protein Shakes?

Nutritious protein-rich foods should always be the foundation of your diet, but supplementing your protein intake with a shake or two offers several advantages.

  • First and foremost, protein shakes are a convenient and easy way to boost your protein intake. They can be especially helpful if you have a small appetite and struggle to meet your protein needs through food alone.
  • Protein is essential for muscle growth. Chugging a protein shake after a workout helps your muscles recover and rebuild. Eating a regular protein-rich meal does the same thing, but not everyone can or wants to sit down to eat after training.
  • Protein shakes can aid with weight loss. Protein maintains muscle mass duringh a calorie deficit when your goal is to lose body fat, makes you feel full and satisfied, and helps you eat fewer calories.

When Is the Best Time to Drink a Protein Shake on Rest Days?

Unlike some dietary supplements that are best taken before or after a workout, you can drink a protein shake at any time and get the full benefits.

Your body doesn’t know where the protein you eat or drink comes from. It just knows that you just gave it what it needs for muscle building. When the essential amino acids appear in your blood, they flip a switch and tell your body, “Hey! We have a delivery of building blocks – time to build lean muscle mass!”

The result is an increase in muscle protein synthesis, the rate at which your body creates new muscle tissue.

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That increase is even greater after a resistance exercise session, but the protein you eat on your off day serves the same purpose.

Great Times to Chug a Protein Shake

  • Some people don’t feel like eating in the morning—a shake boosts muscle protein synthesis without filling your stomach.
  • If a meal is low in protein, adding a shake can give you the right amount of protein for muscle gain.
  • A bedtime protein drink keeps your amino acid levels high throughout the night and helps you build muscle when you sleep.
  • You can also drink protein shakes as a meal replacement or as a snack between meals. They can satisfy your sweet tooth, helping you stay away from unhealthy options while giving your muscles a nice boost.

The bottom line is that you can drink a protein shake at any time on rest days: in the morning when you wake up, before you go to bed, or with or between meals.

The most important thing about protein consumption on rest days is the total amount you get, not the timing. Also, protein from “real food” will work just as well at any of the times mentioned above. A protein shake is a good option but not a must.

Which Protein Powder Is Best?

When choosing a protein powder, you are met with seemingly endless options, which can be confusing.

We can put protein supplements into two categories: animal-based and plant-based.

Animal-Based Protein Powders

  • Whey protein
  • Casein protein
  • Milk protein (a combination of whey and casein protein)
  • Beef protein
  • Egg protein, most often egg white protein
  • Collagen protein

Plant-Based Protein Powders

  • Soy protein
  • Hemp protein
  • Rice protein
  • Pea protein
  • Nut or seed protein
  • Vegan-friendly protein blends that include several different plant-based protein sources

Differences Between Animal and Plant-Based Proteins

  • Animal-based proteins contain enough of all the essential amino acids the human body needs to build muscle. The exception is collagen protein, which is not considered a complete protein. It might offer some benefits for skin and joint health but don’t rely on it if your goal is building muscle.
  • Plant-based proteins have too little of one or more amino acids, except for a few, like soy protein. Your body is very good at combining amino acids to form a complete protein out of incomplete ones, so as long as you eat a varied diet, it doesn’t matter much.
animal protein and plant protein

Different Types of Protein Powder

Choosing a protein comes down to your own preferences. Or intolerances – going for a milk protein if you have lactose intolerance is not the best idea for obvious reasons.

There is little to no evidence that using a particular protein supplement leads to more significant muscle gains than using another.

The most popular and common are whey, casein, and soy protein.

  • Whey protein is a “fast” protein from milk. Your body breaks it down quickly, and the amino acids reach your blood in minutes. Whey protein shakes are available as whey protein isolate and concentrate, both of which are excellent all-around options for everyone from the average active person to elite athletes.
  • Casein protein is another milk protein, but unlike whey, it breaks down slowly and releases amino acids over a long time. It’s a popular option as a nighttime protein to supply building blocks to the muscles while you sleep.
  • Soy protein is the most well-researched plant-based protein supplement, and most studies find it as effective as whey protein for increasing muscle mass, muscle strength, and athletic performance.

Choosing the Right Protein Powder for You

There is not enough research on most other protein powders to determine how they compare to, for example, whey protein for building muscle in the long term. However, recent studies suggest that it’s how much protein you eat overall that matters, not if you get it from animal or plant-based sources.3 4

The bottom line is to use a protein powder that fits your needs and tastes. As long as you consume adequate protein overall, there is little evidence that one is superior. If you are a vegan, pick a plant-based option, but other than that, it likely doesn’t matter all that much.

If you are unsure, whey protein is always a good jack of all trades and one of the least expensive options.

Read more:

>> Whey or Soy Protein for Building Muscle?

How Much Protein Is Enough for Your Shake?

Getting the right amount of protein in your shake is important. Take too little, and you won’t boost muscle protein synthesis properly. Take too much, and you’re wasting money.

Generally speaking, you want to consume 20–40 grams of protein per serving.2 That amount maximizes muscle protein synthesis, at least when you use a high-quality source like whey protein.

For most people, 30 grams of protein per serving is the ideal middle-ground.

The exceptions are after a hard workout where you have trained multiple muscle groups, before you go to bed, and if you’re older than around 60. In all those cases, you benefit from increasing the amount of protein in your shake to 40 grams, on both training and rest days.

protein: 20 vs 40 grams of

Read more:

>> How Much Protein Per Meal Can You Use to Build Muscle Mass?

Are Protein Shakes Safe?

Yes, protein shakes are perfectly safe, unless you are allergic to a certain type of protein or have dietary restrictions for medical reasons.

Protein from a protein supplement does not affect your body in other ways than protein from food, and you don’t have to worry about harmful effects from drinking protein shakes. On rest days or after workouts.

Your body can’t use more than 30–40 grams of protein per serving to build muscle, but consuming more in one sitting is not dangerous nor do you pee it out. Your body simply uses it to build and repair other tissues in your body or as a source of energy. You might consider it wasteful if your goal is to gain muscle, but it’s not harmful.

In addition, no Tolerable Upper Intake Level for total protein consumption has been established, and no adverse consequences (including cancer, kidney disease, kidney stones, and osteoporosis) of high protein intakes have been identified.5

Delicious and Nutritious Protein Shake Recipes

Here are five delicious and nutritious protein shake recipes to enjoy on your well-deserved rest days:

1. Peanut Butter Banana Smoothie


  • 1 banana
  • 1 tablespoon peanut butter
  • 1 scoop vanilla or chocolate protein powder
  • 1 cup milk or almond milk

2. Triple Berry Protein Smoothie


  • 1 cup frozen berries (such as strawberries, blueberries, and raspberries)
  • 1 scoop vanilla protein powder
  • 1/2 cup plain Greek yogurt
  • 1/2 cup milk or almond milk

3. Blueberry Flaxseed Smoothie


  • 1 cup frozen blueberries
  • 1 tablespoon ground flaxseed
  • 1 scoop vanilla protein powder
  • 1 cup milk or almond milk

4. Green Protein Smoothie


  • 1 cup spinach
  • 1/2 cup kale
  • 1/2 avocado
  • 1 scoop vanilla protein powder
  • 1 cup milk or almond milk

5. Tropical Spinach Smoothie


  • 1 cup frozen mango
  • 1/2 cup frozen pineapple
  • 1/4 cup spinach
  • 1 scoop vanilla protein powder
  • 1 cup milk or almond milk


  1. Combine all ingredients in a blender and blend until smooth.
  2. Enjoy!

Should you drink one of these protein shakes on rest days?

Absolutely, if only for the lip-smacking goodness.

These are just a few ideas for delicious and nutritious protein shakes. Feel free to experiment with different ingredients and flavors to find your perfect shake.

Final Words

Can you drink protein shakes on rest days?

Absolutely. They perform the same functions in your body on rest days as on training days. Your body needs protein every day of the week, whether you work out or not. 

Should you drink protein shakes on rest days?

It depends. There is no one-size-fits-all yes or no answer to the question.

  • If you, for any reason, don’t get enough protein from your diet and eating more of your regular food is not an option, then yes, you should fortify your protein intake with at least one shake.
  • If you don’t enjoy protein shakes and have no trouble getting enough protein without them, then no, they are unnecessary for you.

Protein shakes are not a magic bullet. They won’t help you build muscle, lose weight, or improve your athletic performance if you’re not also following a healthy, balanced diet and exercise routine.

However, as part of such a routine, protein shakes can definitely help you reach your daily protein goals and, therefore, your fitness goals faster.


  1. ACSM Information on Protein Intake for Optimal Muscle Maintenance.
  2. Journal of the International Society of Sports Nutrition, Volume 14, Article number: 20 (2017). International Society of Sports Nutrition Position Stand: protein and exercise.
  3. Sports Medicine Volume 51, Pages 1317–1330 (2021). High-Protein Plant-Based Diet Versus a Protein-Matched Omnivorous Diet to Support Resistance Training Adaptations: A Comparison Between Habitual Vegans and Omnivores.
  4. The Journal of Nutrition, Volume 153, Issue 6, June 2023, Pages 1680-1695. Vegan and Omnivorous High Protein Diets Support Comparable Daily Myofibrillar Protein Synthesis Rates and Skeletal Muscle Hypertrophy in Young Adults.
  5. Gropper SS, Smith JL, Carr TP. Advanced Nutrition and Human Metabolism. Eighth ed. Boston MA: Cengage Learning; 2022.
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Andreas Abelsson

Andreas is a certified nutrition coach and bodybuilding specialist with over three decades of training experience. He has followed and reported on the research fields of exercise, nutrition, and health for almost as long and is a specialist in metabolic health and nutrition coaching for athletes. Read more about Andreas and StrengthLog by clicking here.