Should You Drink Protein Shakes on Rest Days?

If you’re anything like me, you always look forward to drinking your protein shake after your workout. Heck, sometimes I feel like the only reason that I work out is to enjoy my post-workout shake afterward! 

This has been a staple in my routine for years now and I’m sure it is for many of you too. 

There is no denying the benefits that can come from protein shakes. 

Most of us know that protein shakes can be great to take after a workout for recovery. However, what about on days you don't work out?

Should you drink protein shakes on non-workout days?

Is this a beneficial thing to do, or a waste?

Believe it or not, there is no one-size-fits-all answer to this question. The best answer I can give you is: it depends.

The short version: Yes, you can drink protein shakes on rest days, and in many cases you should. It comes down to your daily protein goal and whether you're hitting it from food alone.

If the question was, "Can you drink a protein shake on rest days?" ... The answer would be yes, you can. But whether you should drink a protein shake on your rest days comes down to your goals, protein intake, and more.

Don't worry - I'll walk you through everything you need to know so you can make the best decision for you and your goals!

What Is Protein And Why Is Protein Important?

To understand whether you should drink a protein shake on rest days, you need to know what protein does. It also helps to know why protein is so important.

Well, protein is the foundation of most of your body's structure. Your muscles, bones, hair, skin, nails, and so much more are all made of proteins.

Not only does protein  help build and repair cells in your body, but it's also essential for our growth, development, and health (1).

As if that's not enough, protein also plays a big role in achieving your fitness goals. Whether it's building muscle or burning fat, getting enough protein can be crucial. 

What Happens to Your Muscles on Rest Days?

You may not realize that your muscles don't grow in the gym; they grow during recovery. That process is called muscle protein synthesis, and it continues for up to 24 to 72 hours after a workout.

That means the day after leg day, your body is still actively rebuilding and adapting. Which is exactly why your protein intake on rest days is so important. 

If you skimp on protein just because you didn't train, you're potentially shortchanging the very recovery process you're trying to support.

So yes ... rest days are not "off days" for your muscles. They're workdays. Just a different kind.

How Does Protein Help Your Fitness Goals? 

No matter what your goal is, your protein intake is going to matter. 

Since we’re talking about rest days, I can assume that you already work out and have a fitness goal. Am I wrong?

So, with that in mind, how does protein help with your fitness goals? Plus, how is this relevant to whether or not you should drink a protein shake on rest days or not?

Your body needs protein to repair and build muscle tissue. In fact, this is the main reason why protein is so important for reaching your fitness goals.

You see, protein is made up of amino acids. Amino acids are what make up our muscle tissue. Without protein, we wouldn't be able to gain or maintain your muscle. 

To take that a step further, your body needs all the essential amino acids to build muscle. So, without a complete source of protein (protein sources that have all the essential amino acids), there’d be no way for your body to get them (4).

Obviously, it makes sense how this would be important for building muscle. Why is this important for fat loss though?

Well, muscle tissue helps your body burn more calories at rest than any other tissue in the body. If you have more muscle, you'll burn more calories naturally.

By eating more protein when you're trying to lose body fat, you can maintain more of your muscle tissue. This can certainly help out when it comes to reaching a fat loss goal.

On top of that, protein has a high thermic effect. To keep this as simple as I can, this means your body burns a lot of calories just from digesting protein. This can make it easier to put your body in a calorie deficit to lose weight (5).

Roughly a third of the calories you consume in protein are burned through digestion! Isn't that crazy?

Lastly, another benefit of protein for weight loss is how satiating it is. Since you have to burn more calories than you eat every day to lose weight, hunger can set in. I know for me ... This is one of the biggest challenges I face when it comes to losing body fat.

More protein in your diet can help combat hunger and cravings. I consider that to be the cherry on top!

At the end of the day, your calorie and protein intake are the two biggest factors in reaching any fitness goal. 

Calories dictate where the scale goes. Protein helps improve body composition.

So, whether you should drink a protein shake on rest days really comes down to one thing: can you hit your daily protein goal without it? Let's break that down.

Should You Drink Protein Shakes On Rest Days?

You may hear different opinions about whether or not you should drink protein shakes on rest days. Again, the truth is, it depends.

So what does it depend on? It depends on whether or not you are hitting your protein goal with whole foods on your rest days or not.

If you are, great! In this case, you wouldn't need to use protein shakes on rest days. However, you still can if you prefer a protein shake over other protein sources you eat on your rest days.

If you are not hitting your protein goal with whole foods, then I definitely recommend you drink protein shakes on rest days. At the bare minimum, you should look for ways to get more protein on your rest days to hit your goal.

Protein shakes just happen to be a great way to help hit your protein goal! This can be true whether you use them for rest days or days you work out.

Now, this also means you need to know your protein goal and how much you're getting. Otherwise, you won't know whether you should drink protein shakes on rest days or not.

So, how much protein do you need to eat to reach your goals? I'll give you a quick, generalized breakdown.

How Much Protein Should You Have On Rest Days?

Finding out how much protein you need every day is actually a lot simpler than you may think. Plus, your protein intake can remain the same on both training days and rest days (2). 

If you are somebody who resistance trains, then I’d recommend you shoot for at least 1g of protein per lb of bodyweight a day (3).

How you spread that protein out matters too. Your body can only use so much protein at once for muscle repair, so splitting your intake across 3 to 5 meals or snacks throughout the day tends to give you the best results. 

So when people ask, 'should I drink my protein shake on rest days,' my answer is often yes, just to help fill one of those daily protein windows.

This can be a great recommendation whether you want to lose fat, build muscle, or just maintain.

For example, I weigh 195 pounds, and am working on building muscle. That's why I keep my protein intake around 195 grams a day and my calories in a range that allows me to gain weight.

The only other thing you should be conscious of is which kind of protein you take on rest days vs workout days. Even more specifically, the type of protein you take after you work out vs a protein powder you use as a meal or snack throughout the day.

What About Calories on Rest Days?

One thing people often overlook: you're burning fewer calories on rest days than on training days.

That doesn't mean you need to drastically cut back, but it's worth being aware of, especially if you're in a fat loss phase. 

The fix? Either adjust your other meals slightly on rest days, or pick a lower-calorie protein shake option like a plain whey isolate mixed with water. Simple, clean, and easy to fit into any plan.

That's also where convenience comes in. If your appetite is low on rest days (which happens to a lot of people), a protein shake is often the easiest way to hit your target without forcing down a full meal. If you have a busy schedule, same deal. A shake in 30 seconds beats skipping protein altogether.

Choosing The Right Protein Shake On Rest Days & Training Days

What a lot of people don't realize is that there are different types of protein designed for different use cases.After a workout, I always recommend a protein powder that digests more quickly. The reason for this has to do with recovery speed.

Plus, during intense exercise, your body sends blood from your GI tract to active muscle tissue and your lungs. This can put your body in a weakened digestive state during, and immediately after exercise (6).

That's why a rapid digesting protein supplement can be more ideal for after workouts.

The most popular post-workout protein shake you'll find is whey protein isolate. This is essentially whey protein that has been processed to remove a majority of the fats and lactose.

Because of this, the protein is able to digest more quickly to help jumpstart recovery and begin repairing muscle tissue.

For any other time throughout the day, a slower-digesting protein may be a better option. That's because these protein shakes can help keep you fuller for longer. They can also help supply your body with a steady stream of amino acids for longer than a rapid digesting source of protein can.

For rest days, this would be the kind of protein shake I'd recommend that you use.

Of the options you have available, whey protein blends are the most popular. They'll have more fat, lactose, and oftentimes other slow-digesting protein sources like casein.

If you follow a plant-based diet or lifestyle, you can also find vegan protein powders. While these are normally more ideal for meals and snacks, you can use them after your workouts too.

Choosing The Best Protein Shake For You

Which protein shake will be best for you? I'd say that depends on when you'll be using it!

At 1st Phorm, we have quite a few different protein shakes to choose from to cover all your bases.

For post-workout, we offer Phormula-1. Phormula-1 is a rapid-digesting whey protein isolate, designed for recovery after your workouts. We also offer Phormula-1 in a naturally sweetened version, as well as part of our Post Workout Stack. So if you're still asking, 'should I drink protein shakes on rest days,' and convenience matters to you, this is a simple solution.

The Post Workout Stack is a combination of Phormula-1 and Ignition. Whereas Phormula-1 has the protein to help support muscle recovery ... Ignition has the rapid-digesting carbs the body needs to replenish energy after training. If you're someone who weight trains or does high-intensity workouts, this is what I recommend.

For meals, snacks, and more protein throughout the day, we offer Level-1. Level-1 is a slow-digesting whey protein blend of whey protein concentrate, milk protein (which has casein), and whey protein isolate.

There are 10+ flavors to pick from, and I know you’ll love it too! 

Level-1 is also available in a naturally sweetened version if that's what you prefer.

For all my plant-based dieters, don't worry, we have you covered too. Vegan Power Pro can be an excellent option to help you hit your protein goal and recover after workouts. That's why we also offer it as part of the Vegan Post Workout Stack!

If you have any questions, don't hesitate to reach out!

We have a full team of NASM Certified Personal Trainers and Nutrition Coaches right here in St. Louis, Missouri. 

Just give us a call at 1-800-409-9732 or send us an email at [email protected]. We're available Monday through Friday from 6 AM to 8 PM Central and Saturday & Sunday from 9 AM to 7 PM Central. We'll be more than happy to help in any way we can!

…and don’t forget to hit that protein goal! You can shop all of our protein powders and supplements here.

Frequently Asked Questions

Should I drink protein shakes on rest days if I’m trying to lose weight?

Yes, as long as the shake fits within your daily calories. Protein helps you hold on to muscle while you’re in a calorie deficit. It also keeps you fuller between meals, which makes hunger easier to manage. You burn fewer calories on rest days, so choose a leaner option like a whey isolate mixed with water, or trim your other meals a little to make room for it.

Will a protein shake on a rest day make me gain fat?

Not on its own. You gain fat when you eat more calories than you burn over time, not because of one food or drink. Most protein shakes land somewhere around 100 to 200 calories, depending on the powder and what you mix it with. If your total intake stays in line with your goal, a rest day shake helps you hit your protein without slowing your progress.

What’s the best time to drink a protein shake on a rest day?

Rest days don’t have a set time you need to hit. Your total protein for the day matters most. A good approach is to use your shake to fill a gap between meals, like a mid-morning or afternoon snack, so your protein stays spread across 3 to 5 meals or snacks. Some people also like a slower-digesting shake such as Level-1 before bed, which gives the body a steady supply of amino acids overnight.

Can I drink two protein shakes on a rest day?

Yes, if you need them to reach your protein goal. Just remember that shakes add to your diet. They don’t replace it. Whole foods like lean meat, eggs, Greek yogurt, and fish give you vitamins, minerals, and fiber that a shake can’t fully cover. A good rule of thumb is to get most of your protein from meals and use one or two shakes to close the gap.

Do I need less protein on rest days than on workout days?

No. Your muscles keep recovering and rebuilding for 24 to 72 hours after training, so you need just as much protein. Keep your daily target the same, around 1 gram per pound of bodyweight if you strength train. What can change on rest days is your calorie intake, since you burn less energy overall.

References:

(1) Wu, Guoyao. "Dietary Protein Intake and Human Health." Food & Function, vol. 7, no. 3, 2016, pp. 1251-1265.

(2) Roberts, Justin, et al. "The Short-Term Effect of High Versus Moderate Protein Intake on Recovery After Strength Training in Resistance-Trained Individuals." Journal of the International Society of Sports Nutrition, vol. 14, no. 44, 21 Nov. 2017.

(3) Sutton, Brian G. NASM Essentials of Personal Fitness Training. 7th ed., Jones & Bartlett Learning, 2022.

(4) Volpi, Elena, et al. "Essential Amino Acids Are Primarily Responsible for the Amino Acid Stimulation of Muscle Protein Anabolism in Healthy Elderly Adults." The American Journal of Clinical Nutrition, vol. 78, no. 2, 2003, pp. 250-258.

(5) Moon, Jaecheol, and Gwanpyo Koh. "Clinical Evidence and Mechanisms of High-Protein Diet-Induced Weight Loss." Journal of Obesity & Metabolic Syndrome, vol. 29, no. 3, 2020, pp. 166-173.

(6) Brouns, F., and E. Beckers. "Is the Gut an Athletic Organ? Digestion, Absorption and Exercise." Sports Medicine, vol. 15, no. 4, Apr. 1993, pp. 242-257.