Protein Shakes—Should You Drink One Even on Rest Days?

When starting your fitness journey supplements like protein shakes, pre-workout, and creatine can seem a bit overwhelming. It may be difficult to determine what you should take and when you should take it. 

Although there are many people that believe you should only drink protein powder after a workout, during your so-called “anabolic window,” studies show that’s not necessarily true. Some people do enjoy the convenience of a protein shake on workout days, especially if you increase your overall consumption of calories or protein on training days.

There are reasons why you might prefer to only have protein shakes on workout days, but rest days are also a crucial time to get proper nutrition. Rest and recovery require protein along with carbohydrates and fats, to support tissue healing and muscle growth. Here we discuss the benefits of protein, why people drink protein shakes, and whether or not you need one on rest days.

Benefits of Protein

Protein is the building block of muscle. It is made up of amino acids that allow our muscles to grow and repair when they are damaged from working out. This means that regardless of whether you are drinking protein powder or getting your protein from food, protein is an essential part of muscle hypertrophy, and it helps you recover after a workout. 

Research also suggests that whether you are supplementing protein or eating foods high in protein—such as eggs and chicken—you should aim for up to two times as much protein as the recommended dietary allowance (RDA) of protein if you want to gain muscle. The RDA of protein is .36 grams per pound of body weight.

Additionally, protein has a higher thermic effect than fat and carbs—or takes more energy to digest. It also can help boost metabolism and increase the calories you burn even when you’re resting. By adding higher amounts of protein, you are staying fuller longer and will actually burn more calories even when you aren’t exercising, like on rest days. 

Protein is also very satiating, meaning it will help keep you full for longer. If you tend to be busy between meals and need your meal to keep you satisfied for a significant time, protein can help. This is also helpful if your goal is weight management.

Why People Drink Protein Shakes

People drink protein shakes mostly for convenience. The majority of people can get adequate protein from food, but with jobs, school, kids, and more, life can sometimes get in the way of getting all the food, protein, and nutrients you need.

Protein powder, which comes in both milk (whey or casein) or plant-based (pea, hemp, brown rice, pumpkin seed) options, generally has around 25 grams to 30 grams of protein per serving. This amount easily fits into most eating plans given that evidence suggests that you should consume anywhere from 20 to 40 grams of protein at a time.

While protein shakes may have been initially consumed primarily by bodybuilders, they have become more mainstream. If you are on a fitness journey and want to gain more muscle, protein shakes can help to add an extra lump of protein after a long or busy day, but they are not necessary.

If your sole purpose in the gym is to gain muscle, some studies show you should be in a calorie surplus or a “bulk.” This means that you will have more room in your diet for whole foods high in protein and may not need to use supplementation to achieve your macro goals. 

If your goal in your fitness journey is weight loss, protein is vital. Many protein powders are low in calories and high in protein, so that they can be a great addition to your daily meal plan. Most experts agree that about 30% of your calories should come from protein if your goal is to lose weight.

For example, if you eat 2,000 calories a day, 600 of those calories should come from protein. Eating more protein adds to the chance of muscle growth, but it can also help you stay full longer, which may, in turn, lead to fat loss. 

Do You Need a Protein Shake on Rest Days?

The bottom line is that you never need to take protein powder. You can get just as much, if not more, protein and other nutrients from whole food sources. Instead, make sure you are eating a balanced diet. Using protein powder as a substitute for other naturally derived protein sources such as eggs, fish, and chickpeas could lead to deficiencies in certain nutrients over time. 

However, protein shakes are a great tool if you have a busy life and don’t have a lot of time to prepare meals but still want to have high protein in your diet. Whether you have a training day or a rest day, you should still be getting up to two times as much protein as the RDA a day. While the data on the timing of when you should consume protein is inconclusive, no doubt prioritizing proper amounts of protein daily and over time will increase muscle mass.  

A Word From Verywell

Protein shakes are a convenient way of making sure you get enough protein. If you are trying to increase your muscle mass, they can become especially valuable post-workout. However, there's no reason not to drink protein shakes on rest days, if you'd like to.

Overall the most important thing is eating a balanced diet and getting the right amount of protein for you daily. Even if you are not on a fitness journey and your goal is not to lose weight or gain muscle, you should still be getting an adequate amount of protein. If you need help determining how much protein you need in a day's time, talk with a healthcare provider or a registered dietitian.