What is a Post Workout Supplement
The idea behind using post workout supplements is to replenish the depleted resources in your body drained from your workout. The most common goals are to restore spent glycogen supplies (carbohydrates stored by muscles for energy) and to supply amino acids (from protein) to your muscles to begin repairing them.
The standard practice is to consume post workout supplements immediately after a workout, but as you’ll see as you keep reading, this may or may not be best.
The Science Behind Post Workout Supplements
I’ll warn you beforehand, this is a pretty long section, but if it’s something you’re interested in it shouldn’t be too bad. One of the problems with post workout supplement research is that the research is incomplete. There are several gaps in our information network and no one knows 100% what the best practice is. I will do my best to present what information we do have in a digestible way and try to draw any conclusions that we might be able to.
Insulin is a hormone that transports carbohydrates, amino acids, and all sorts of other useful things to our muscles. One of the benefits of regular exercise is that it helps you become more insulin sensitive. If you have high insulin sensitivity, when you consume carbohydrates or amino acids (broken down from protein) there will be a fast release of insulin which means that your muscles will get the nutrients fast. If you have poor insulin sensitivity (like people with metabolic syndrome) there is no significant spike in insulin, so transport of nutrients is slow or non existent, which is obviously a huge problem, one that exercise can help correct over time.
Studies have shown that after extreme exercise you can actually become insulin resistant for a short time, but the exact mechanism isn’t known . It is possible that inflammation of cells blocks the signalling process or free fatty acids (FFA) are broken down in the bloodstream to be used as energy which inhibits insulin activity. Either way unless you are in the gym for an extremely long time you don’t have to worry about this, because studies have shown that the body will react to most normal workouts by becoming more insulin sensitive instead . We’ll come back to how this may play into the picture later.
Muscle Protein Synthesis/Breakdown
When amino acids arrive in your muscles via insulin transport if they are used it’s to manufacture proteins to maintain or build muscle. This process is called protein synthesis, and muscle protein breakdown is essentially the opposite, where the muscle proteins are broken down either by trauma (exercise) or by the body for energy under extreme conditions. When protein synthesis is faster than breakdown we are in an anabolic (muscle building) state, and when breakdown is the faster of the two we are in a catabolic (muscle wasting) state. Obviously at some point after a workout we will want to be in an anabolic state.
The Effects of a Workout
During a workout we are essentially tearing muscle fibers. This results in a significant increase to the rate of muscle protein breakdown. Protein synthesis on the other hand typically stays at the base level or can increase a bit if you have sufficient amino acids stored. At some point muscle breakdown will exceed synthesis and their will be a net breakdown of muscles, which is what we’re aiming for, since we want to stress the muscles and build them up stronger later.
Another effect of working out as we partially alluded to earlier is that as your body depletes of glycogen and migrates into a catabolic state, your insulin sensitivity rises. If you do consume either carbohydrates or protein your body will rapidly absorb them, if you do so within a certain period of the workout (which ranges from 0-60 minutes depending on who you ask), which is often referred to as the “window of opportunity”; we will discuss if we indeed want to consume nutrients in this period. Research has shown that nutrient uptake is much higher within 1 hour of a workout than at 3 hours after a workout .
Timing of Nutrients
Several studies have looked at how different amounts and timings of nutrient ingestion affects absorption rate. First and foremost when looking at having a protein supplement before a workout versus right after, there have been multiple studies published by Tipton. In his first major study that everyone references he looked at this situation and concluded that amino acids (in particular phenylalanine) taken before a workout were absorbed much faster and better than after .
There were a few methodology flaws in his analysis, which to be fair he covered in a similar study he did years later. He essentially repeated the study but with a complete whey protein shake, from the picture I’ve attached from the right, we see that total protein intake is the same. The research also showed that protein synthesis for the pre workout drink group spiked during the workout before rapidly returning to normal. On the other hand when the protein was taken afterwards, the rate of protein synthesis spiked to a much lower amount than the other group, but it sustained this increase for much longer .
Neither one is necessarily better than the other, but it certainly is different, and as we will see in future sections some people should have protein before a workout, and others should have it after. Also, one possible theory from this work is that it might be best to have protein before and after a workout, but so far no research has looked at this topic.
Quick Myth Busting: Post Workout Supplements Need Carbohydrates
The idea behind this originates from a hypothesis surrounding insulin. We need insulin to transport amino acids right? So more is better right? Which led to people saying that since ingesting carbs spikes insulin much more than protein alone that carbs should be consumed post workout with any protein. Research has disproved this and the bottom line is that the presence of carbohydrates doesn’t affect the post-exercise muscle protein balance, likely because any protein by itself will cause a sufficient insulin spike in the insulin sensitive state .
What are our Goals For a Workout?
Before we go any further we need to establish what we want to do and why. Let’s look at protein first, widely regarded as the most important part of post workout nutrition. The standard advice is to consume protein right away after in order to start the repairing process, but here’s the thing, there have not been any long-term studies (to my knowledge) that compared ingesting protein right after a workout with waiting a few hours to eat.
I would propose that depending on your workout goals and schedule that ingesting protein right away may not be ideal. With the lack of research in this particular area, a lot of answers for you will come from trying to apply some thought towards the problem (which we will do now together) and self-experimentation in the future.
When you workout you are purposely increasing the rate of muscle breakdown, to the point where the net state of your muscles is catabolic – breaking down. When you consume protein, either before or after a workout you alter this balance and bring it back into a positive net muscle protein state, which is anabolic. This means that you start repairing pretty soon after ingesting the protein. My question to you is do we want to do this? I think this depends on two things, your goals and your schedule.
If you want to get the maximum adaptation from the work you have just put in, you essentially want to cause the most damage to your muscles so that they will adapt more. If you just wanted to cause a bit of damage you could just do short little workouts, but obviously that seems silly. In essence though in my opinion you are minimizing the effects of your workout by supplying amino acids right away while breakdown is still occurring.
Now at the same time, if you’re planning another hard workout or activity that will use the muscles you just damaged, you may want to limit the damage and accelerate the repairing process by ingesting the protein before a workout or immediately after; this would make sense.
If you have plenty of rest though, you can take a similar approach Ori Hoffmenkler (creator of the warrior diet) who advises to wait 30-45 minutes after a workout before ingesting protein or food.
How Much Protein is Needed
If you are consuming protein at any time it’s because you want to initiate the transition to an anabolic state, which needs to occur at some point. Studies have been done on men of different ages to see how much protein the body can utilize. To keep it brief, in young men 20 grams stimulates the maximal protein response (muscle synthesis), but in older men (~70 years old) 40 grams are needed   .
The final issue regarding protein is should you take a bit at a time, maybe split it pre and post workout, or drink a lot at one time. Interestingly enough, research has found that a high peak level of amino acid levels causes more muscle protein synthesis than a steady amount . What this means is that if someone drinks 40 grams all at once, as opposed to someone drinking it over a time period, the person who drank it all at once will have more muscle protein synthesis even though the total amount absorbed is the same. The mechanism behind this isn’t known, but is an interesting area for further studies.
But What About Carbohydrates?
I haven’t forgot about them, don’t worry. As we saw earlier the carbohydrate issue is unrelated to the protein issue but still important. Hard exercise will drain your glycogen stores, and again depending on your goals you may or may not want to replenish these right away.
If you are going to be working out or exercising very soon then it is advisable to have some carbohydrates as part of your post workout meal or shake. However, there is a trade-off when you do this.
By the end of a workout your body has mobilized Free fatty acids (FFA) to use for energy, since it can see that your glycogen stores are depleting. At the end of your workout you will typically have a significant amount of FFA in your bloodstream which are ready to be burnt off for energy. As soon as you consume those carbohydrates your body knows that is your preferred fuel for training so it brings out the insulin to shuttle them to your glycogen, but at the same time it returns the FFA to your fat cells instead of burning them. Obviously if you are trying to lose weight this is a BAD thing. Instead try to postpone eating carbs for a few hours to burn those available FFA for energy. Ideally do some low impact exercise (walking) to encourage this. You can always replenish your glycogen later, but this is a great opportunity to burn some fat.
In summary post workout supplements are not so simple…
I will try my best to summarize the key points on this page:
Protein needs to be consumed at some point before or after a workout to transition the body back into an anabolic state
If you need to exercise soon or will not have sufficient rest you should consume protein either right before the workout or right after
If you will have time to rest and give the particular damaged muscle group some time to heal, ingest protein after 30 minutes-an hour in order to reap the full benefits of your workout
If you are younger you don’t need much more than 20 grams of protein around your workout, but the older you are the more you need, and if you are elderly you’ll need around 40 grams for the best response
Unless you need to exercise soon after hold off on ingesting carbohydrates, because this will allow you to burn the FFA in your bloodstream as a result of your workout.
I hope that will allow you to understand your own situation better so you can decide what you want in a supplement so you can find the best post workout supplement for you and know how to use it.
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