The age-old question: Should you consume your protein shake before or after workout sessions?
This may be one of the most controversial debates in the fitness space — with some people advocating a protein shake is best consumed pre-workout, and others adamant about taking their protein post-workout.
To provide an adequate answer, we must first examine why protein is important, how much you need, and what type you should be eating. Whether you’re trying to build muscle or lose weight, this knowledge is essential. After that, we’ll reveal whether a protein shake before or after workout is best.
Protein plays a part in virtually every single cell in your body. Your body uses protein to:
Without getting into the nitty-gritty of protein synthesis, the basics are: Proteins are built from amino acids, and amino acids are involved in almost every body function.
Some amino acids are non-essential, meaning your body can make them on its own. Others are essential, meaning your body cannot make them, and you must get them through your diet. Real foods like meat, eggs, cheese, milk, and fish are great sources of all nine essential amino acids.
After you drink a protein shake or eat a piece of steak, your body breaks the protein down into individual amino acids and small peptide fragments.
When it comes to building skeletal muscle, like your biceps, triceps, quads, and more, protein is essential. During your workout, you actually break your muscles down.
Exercise causes microtears in muscles. To repair these microtears, your body builds new muscle proteins from amino acids. Your body also activates satellite cells to help with tissue damage. The satellite cells help repair muscle fibers, making them bigger and stronger than before.
That's the gist of muscle building, but there's a catch.
Your body can only build muscle if there are enough amino acids to repair the microtears caused by exercise, plus some extra aminos to take muscle growth even further. (Rather than returning you to your pre-exercise baseline before the tears occurred.)
If you don’t have a sufficient supply of amino acids, your body can’t repair the microtears in your muscles. Not only will your recovery suffer — you won’t bulk up and gain muscle mass. (Hello, injuries and muscle loss.)
Research in the journal Food & Function shows that too little protein in the diet can also stunt growth, lower immunity, reduce strength, contribute to edema, and cause vascular dysfunction.
Ensuring your body has plenty of amino acids to adequately repair your tissues comes down to eating enough protein.
A scientific article in the journal Food & Function recommends healthy sedentary adults consume 0.8-1.0 grams of protein per kg of body weight per day.
However, the amount of protein you need varies depending on your physical activity level.
If you’re moderately active, your protein requirements increase to 1.3 grams per kg of body weight per day. If you participate in intense physical activity, your recommended daily allowance may be upwards of 1.6 - 1.8 grams of protein per kg of body weight per day.
We don’t recommend consuming more than 2.5 grams of protein per kg of body weight per day. According to the same research in Food & Function, “chronic high protein intake may result in digestive, renal, and vascular abnormalities.”
As you can see, the amount of protein you consume matters, but so does the type of protein. The quality of protein is only as good as the ingredients it’s made from. Let’s examine different types of protein and how they affect muscle building.
If you like to drink protein, there are a few different protein supplements to choose from. Whatever you choose, focus on high-quality supplements with no artificial sweeteners, coloring, or preservatives. The best protein powders are also gluten-free and non-GMO.
Whey protein is incredibly popular and very well studied. It’s known as a complete protein because it contains all nine of the essential amino acids your body can’t produce on its own. It also has a high concentration of branched-chain amino acids (BCAA) — a group of three essential amino acids helpful for muscle recovery and growth.
Depending on how it’s processed, you can end up with whey concentrate or whey isolate. According to an article in the Journal of Sports Science and Medicine, whey concentrate “typically contains more biologically active components and proteins” than isolates. This makes it a very attractive supplement for athletes who want to build muscle.
Whey isolate is the purest protein source there is with protein concentrations of 90% or more. While concentrations are higher, the processing denatures the proteins, making it less biologically active than its whey concentrate counterpart. However, many lactose-intolerant people fare better with whey isolate, as most of the fat and lactose are removed during processing.
Like whey protein, casein also comes from milk. (Casein makes up 80% of the protein in milk, while whey is 20%.)
The main difference between whey and casein protein is the speed at which your body digests it. Casein digests slowly, while whey digests quickly. Due to the slow digestion time, casein is a popular protein to reduce muscle breakdown.
A study in the Medicine & Science in Sports & Exercise journal found supplementing with casein protein before bed stimulated muscle protein synthesis and helped with muscle recovery overnight.
Whether you adhere to a vegan diet or not, vegan protein powder can be a great option.
Not only is it high in protein (especially rice and pea protein powders) — it’s also high in fiber. Vegan protein powders can be easier to digest than their dairy counterparts, especially for people with milk sensitivities.
Plus, you aren’t sacrificing any muscle growth by sticking with vegan protein. A study in Nutrition Journal found rice protein to be equally as effective as whey protein for muscle recovery and growth.
Now, back to the essential question: Should you drink a protein shake before or after a workout?
A study in the Journal of the International Society of Sports Nutrition found that ingesting protein post-exercise greatly stimulated muscle protein synthesis, but only if the protein was consumed within 2 hours after the training session.
However, in another study, they also found that muscle growth occurred when protein was consumed pre-workout.
So, the official position of the International Society of Sports Nutrition is resistance training, combined with protein consumption, stimulates muscle protein synthesis — regardless of whether protein consumption occurs before or after exercise.
In layman’s terms, it doesn’t really matter if you drink your protein shake before or after your workout. It’s more important to get enough protein than it is to consume it at a specific time. For best results, try to consume protein every 3-5 hours throughout the day.
Whatever your fitness goals, tracking how much protein you eat is more important than worrying about when you eat it.
Drinking a workout protein shake is a convenient way to get enough protein for muscle recovery and bulking up. You can add some protein powder to your smoothie, favorite milk, coffee, or just mix it with water.
Remember: Your protein needs increase with your physical activity level — up to a point. We don’t recommend eating too much protein, as it may damage your overall health.Note: This article does not constitute medical advice. Always work with a dietitian, nutritionist, or other healthcare professional before adding a new supplement to your diet.
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