A protein shake is a convenient way to consume protein for various health goals. The best time to drink a protein shake may depend on whether the goal is to build muscle, enhance performance, lose weight, or meet daily nutritional needs. Exact timing may not be as important as spreading protein consumption throughout the day.

1. For Muscle Building

Protein shakes can be a quick and effective way to increase protein intake when your goal is to build muscle. Your body uses protein from the diet to make new muscle proteins. Increased protein promotes strength and muscle mass gains when paired with resistance training (such as lifting weights).

Studies have found that timing protein intake immediately after resistance training does not impact strength, power, or body composition changes.

Instead, getting 20 to 40 grams (g) of high-quality protein every three to four hours most favorably affects muscle protein synthesis (creation) rates compared to other eating routines. This pattern of spreading protein intake throughout the day is associated with improved performance and body composition (amount of fat and lean tissues).

The total daily protein recommended to increase muscle mass with resistance exercise is 1.6 to 2.2 g per kilogram (kg) of body weight (g/kg). For a 150-pound person, that equals 68 to 109 g of protein per day.

Before or After a Workout

Drinking a protein shake before a workout could cause digestive upset during the exercise. Fortunately, drinking one after a workout can still help meet protein needs.

Before Bedtime

When considering bedtime snacks, consuming about 30 to 40 grams of casein protein before sleep may increase muscle protein synthesis and metabolic rate (the amount of energy you use at any given time) throughout the night without affecting the breakdown of fat energy stores.

2. For Endurance and Performance

Endurance athletes can also benefit from drinking a protein shake. A meta-analysis of studies concluded that protein supplementation:

• Increased aerobic capacity (the maximum amount of oxygen your body can use at one time during an intense exercise)
• Promoted building lean muscle mass
• Improved time trial performance during endurance training

Protein needs are greater on days with higher training volumes than on days without exercise or with lower training volumes. However, consuming protein shakes on non-workout or rest days is still acceptable and can be a convenient way to support overall health and performance goals.

Endurance athletes should consume protein in addition to carbohydrates after exercising to help offset muscle damage and promote recovery.

In addition to adequate carbohydrates, general protein guidelines recommend consuming 0.25 to 0.3 g/kg or a maximum of 20 to 40 g of protein in the post-exercise recovery period. This equals 17 to 20 g of protein for a 150-pound person.

3. For Weight Loss

Protein shakes also have several benefits for weight loss, which include:

• Promoting satiety: Protein is the most effective macronutrient for promoting satiety (feeling full). High protein diets increase hormones in the gut that decrease appetite while also decreasing ghrelin, which increases appetite.
• Control appetite: Eating a high-protein breakfast (around 30 g) can help control appetite throughout the day and prevent overeating at lunchtime.
• Burn more calories: Protein has a higher diet-induced thermogenesis, which causes the body to burn more calories after eating, thus boosting metabolism.
• Low in calories: Protein shakes generally contain 100 to 200 calories per shake. Choosing a lower-calorie protein shake can help you maximize your protein intake while staying within your daily calorie limit. 

Many people use protein shakes as meal replacements. However, protein shakes are not necessarily designed to be meal replacements, and many meal replacement drinks on the market contain a good amount of protein.

Meal replacement shakes generally contain 200 to 400 calories and the necessary nutrients to replace a meal.

4. For Meeting Daily Protein Goals

Protein shakes are frequently used to help meet daily protein goals, especially for individuals who struggle to eat enough throughout the day. For this reason, protein shakes may benefit aging people with decreased appetite or others with a loss of appetite, such as people undergoing cancer treatments.

The recommended dietary allowance (RDA) for protein is 0.8 g/kg daily for adults 18 or older. This is the minimum amount needed for basic nutritional requirements, but some experts argue that the amount required for optimal health is higher.

Certain populations often have greater daily protein requirements, sometimes making it difficult to meet their needs from food alone. These include:

• Bodybuilders and athletes
• Older adults
• Pregnant and lactating people
• Young children

When approved by a healthcare provider, protein shakes can supplement daily protein intake in these special populations, helping them meet their macronutrient goals.

Types of Protein in Protein Shakes

Many different types of protein are available. They may be available as a protein powder or in a ready-to-drink protein shake. Commonly used types of protein include:

• Whey protein: Dairy-based, quickly absorbed, and contains all essential amino acids
• Casein protein: Dairy-based, slowly absorbed, and provides all essential amino acids
• Soy protein: Plant-based, easily digestible, and offers all essential amino acids and soy isoflavones (plant compounds that may provide health benefits)
• Pea protein: Plant-based and less allergenic alternative to soy and whey protein, but lower in two essential amino acids (methionine and cysteine)
• Rice protein: Plant-based, highly digestible, but lower in the essential amino acid lysine
• Hemp protein: Plant-based, contains all essential amino acids, with a high arginine content
• Egg protein: Animal-based, medium absorption, and provides all essential amino acids
• Collagen peptides: Animal-based, quick absorption, lacking in the essential amino acid tryptophan

Summary 

Protein shakes can be a convenient way to take in protein for various health goals, such as muscle building, endurance training, or weight loss. The best time to drink a protein shake can vary depending on your health goals.

Consuming protein benefits muscle growth and recovery. However, exact timing may not be as important as getting enough protein and spreading protein intake throughout the day.

The RDA for protein is 0.8 g/kg for healthy adults, though older adults, young children, pregnant and lactating people, bodybuilders, and athletes require more.