The Best Time to Take Whey Protein – Before or After a Workout?

The Best Time to Take Whey Protein – Before or After a Workout?

In this article, we look at the best times to take whey protein depending on whether you want to build muscle, lose weight, or preserve muscle. Like most supplements that are taken to build muscle, it’s important to incorporate whey protein before and after a tough workout.

Protein Before or After Working Out?

However, there has been a never-ending debate on when is the best time to take protein for optimal muscle growth. Some fitness enthusiasts recommend taking a protein supplement 15-60 minutes after exercise.

This time frame is often referred to as the “anabolic window”––where the body gets the most out of a protein supplement right after a workout. During resistance training, the body breaks down protein naturally. Therefore, to build more muscle, you need to replenish and build the muscles up again with more protein.

According to research conducted at McMaster University, taking dietary protein, such as whey protein, by resistance-trained athletes, helps generate more muscle protein

On the other hand, other fitness gurus recommend consuming 20-30 grams of whey protein 30-60 minutes before you start your workout. This helps to create a positive nitrogen balance in the body, stimulating protein synthesis, which encourages muscle growth. 

In an attempt to address this controversial topic, the International Society of Sports Nutrition (ISSN) published research on nutrient timing in highly trained individuals.

The research showed that the timing of nutrients such as whey protein supplements enhances recovery and tissue repair. The study concluded that consuming protein about 2 hours after a workout helps build muscle mass. But is this really true, given what we now know about the anabolic window?

The Anabolic Window 

Sports nutritionists and athletes often talk about something called the ‘anabolic window’—a period of time when absorption is at its highest, allowing muscles to absorb maximum amount of nutrients for recovery and muscle growth.

Most people will say that this “refeed window” ranges from 30 minutes to 1 hour after exercise, but this isn’t necessarily true. While absorption rates may be higher directly following a workout, many factors contribute to how the body absorbs fuel. 

Many early studies use fasted subjects to look at the effects of nutrient timing on body composition, strength, and muscle size. Because fasting puts the body in a catabolic state to begin with, eating directly after exercise may be more important in situations such as promoting muscle synthesis and glycogen storage.

However, if you’re not training in a fasted state, there’s less urgency to re-fuel directly afterwards. If you’ve consume 20g of protein or more pre-workout, plasma amino acid levels should remain elevated for 2-3 hours post-consumption making it unnecessary to eat immediately after working out.

Therefore, even if there is a delay in refuelling after training, your pre-workout meal will suffice to supply you with enough amino acids for muscle growth and repair.

Despite claims that refuelling directly after activity is essential to maximize hypertrophic gains, there is a significant amount of evidence that suggests there is no definitive ‘anabolic window.’

Most of the research conducted around this concept is based on research conducted in a fasted state. If this is the case, there is an increase in muscle protein breakdown due to a net negative amino acid balance that persists after exercise is completed regardless of the exercise-induced increase in muscle protein synthesis.

Therefore, the principle of the anabolic window right after exercise to maximize muscle protein synthesis would make sense if resistance training occurred following an overnight fast. 

Protein Before Bed

If you’re looking to build muscle, increase strength, and improve exercise recovery, it’s a good idea to take protein before going to sleep as well. One meta-analysis examined the effect of protein consumption before sleep.

The results found that taking protein before bed is effective at promoting muscle growth and increasing muscle adaptability and recovery from exercise. These results are likely due to proteins high bio-availability, meaning that it’s easy for the body and muscles to absorb and assimilate protein during sleep.

With this in mind, researchers recommend 40 grams of protein before bed to maximize muscle growth during sleep.

A study published in The American Journal of Physiology: Endocrinology and Metabolism found that older men who took casein before bed saw a greater improvement in muscle protein synthesis compared to older men who didn’t take casein.

When it comes to consuming protein before bed, casein protein shows the most promising results for muscle growth and recovery during sleep. Compared with whey protein, casein delays gastric emptying, which causes a prolonged increase in plasma amino acid levels. On the other hand, whey protein is easier to absorb, leading to a more pronounced but temporary rise in plasma amino acid levels.

You can purchase casein supplements from most health food stores. Many dairy products also contain casein (with high amounts of casein found in cottage cheese and Greek yogurt).

Best Time to Take Protein 

A study conducted by the University of Texas examined the timing of amino acid/carbohydrate consumption and the anabolic response of muscles to resistance training. The study found that a small dose of essential amino acids, 6 grams, taken after exercise, increased amino acid levels by up to 130 percent.

In this case, amino acid levels remained elevated for several hours after training had stopped. Another study by the same group of researchers found that consumption of 20 grams of protein post-exercise increased amino acid uptake by 440% compared to pre-exercise levels. In this case, amino acid levels did not return to normal until three hours after exercise.

With this research in mind, a minimal-to-moderate amount of essential amino acids or high-quality protein consumed before exercise can sustain amino acid levels well into the post-exercise period. 

Some studies show that the anabolic effect of a meal can last up to six hours based on the rate of amino acid metabolism. In contrast, studies in both rats and humans suggest that amino acid levels return to baseline in three hours despite high amino acid availability.   

It’s advisable to consume at least 25 grams of protein when training occurs 3–4 hours after your last meal. Protein consumption helps put the body back into an anabolic state and ensures you have enough available amino acids. 

Furthermore, a study published in the Journal of Physiology suggests that older people require more protein than younger people to optimize their anabolic response to training.

How Much Protein?

Protein requirements vary depending on gender, age, activity level, and other factors that affect body function. However, a recent meta-analysis concluded that individuals partaking in resistance training should aim for between 1.6–2.2 grams of protein per kilogram (2.2 pounds) of bodyweight.

Best Time to Take Protein

The same meta-analysis that looked at 23 studies on protein timing, found that the quantity of protein intake throughout the entire day had a greater effect on muscle growth than the time the protein was consumed.

If you’re looking to increase muscle mass, you should aim for a minimum of 0.7 grams per pound of bodyweight (1.7 grams per kilogram) of bodyweight. As an example, that means a 185 lb. (84 kg) person should consume 143 grams of protein per day, at a bare minimum, to promote optimal muscle growth and repair. 

While protein consumption immediately after exercise may help to promote an increase in muscle synthesis under certain conditions, consuming adequate protein throughout the day appears to be more important.