The Muscle-Building Messenger: Your Complete Guide To Insulin
Years ago, insulin was only discussed in reference to diabetes. Insulin is the hormone that drives glucose out of the bloodstream and into cells, and diabetes is the loss of the ability to control blood glucose levels. Yet insulin is so much more than a hormone that controls glucose. For one, it's highly anabolic, which means it's critical for building muscle.
Insulin also has a dark side, because it can increase fat storage. The challenge is to learn how to spike insulin to optimally recover from workouts and grow, while also blunting it to stay lean.
Do you know all the facts about insulin and how to use it to your advantage? Don't be so sure. If not, my insulin guide will teach you how.
Insulin and Muscle
Insulin is actually a protein, and it is produced and released by the pancreas whenever you eat carbs, protein, or both. (That is, if the pancreas is working properly). Yet unlike the proteins that are the physical building blocks of muscle, this is a functional protein, much like growth hormone.
Like all other proteins, insulin is a chain of amino acids strung together. But the way this protein chain is folded makes it act more like a signaling mechanism than a building block.
From the pancreas, insulin enters the blood stream and travels to various tissues, including muscle tissue. The muscle fibers (or cells) are lined with insulin receptors, similar to a docking station. Once the insulin molecule docks onto the receptor, it signals the muscle cell to open up gates. This allows allow glucose, amino acids, and creatine to enter the muscles. This process is a major reason why insulin is so important for building muscle.
Another reason is that when insulin docks onto the muscle cells, it instigates biochemical reactions in the muscle that increase protein synthesis, which is the building of muscle out of the amino acids that are entering the muscle cells. In addition, insulin also decreases muscle breakdown, which further enhances muscle growth.
Insulin also indirectly aids in muscle development by causing the blood vessels to relax and dilate, allowing greater blood flow to the muscles. By increasing blood flow, insulin can help get even more nutrients like glucose and amino acids to the muscles. This is why you'll see bodybuilders pounding simple carbs on contest day. Not only does the corresponding spike in insulin drive the carbs into the muscles to keep them full, it also boosts vascularity.
Insulin and Fat
Insulin's release from the pancreas signals the body that it has just been fed. Since the body is always trying to spare energy, it halts the body's burning of stored fat, instead turning to the nutrients that have just been ingested. Meanwhile, insulin also works on fat cells similar to how it works on muscle cells, signaling the gates to open and nutrient storage to commence.
An increase in the uptake of glucose and fats causes the body to store more body fat. More fat is stored, less is burned—you can see how spiking insulin levels throughout the day would lead to fat gain over time.
As long as those insulin receptors work as designed, a spike in insulin levels clears out the majority of the glucose in the blood, pushing it into muscle and fat cells.
This lowers blood glucose levels in an orderly fashion, if someone has a healthy glucose metabolism, but it can also lead to a crash—either because the person's glucose tolerance is impaired, or too many simple carbs were consumed at once. The low blood sugar that results from a crash is known as hypoglycemia.
A crash will make you feel like your energy levels have been zapped. Not only is this bad for your general well-being, but it's bad for your physique. What's more, when your energy crashes, your hunger soars. This often causes people to over-eat. For most of us, this means reaching for simple carbs—which can lead to another crash.
Master Your Insulin Levels
Since insulin has a good side and a bad side, it's crucial to know how to use insulin for your gain—muscle gain, that is—while avoiding its effects on fat gain. Follow these six rules and you'll be good to go.
The types of carbs you eat can make or break your ability to rule insulin. Carbs can be categorized into two basic categories: 1) high glycemic index (GI) carbs and 2) low GI carbs. The glycemic index refers to how fast the carbs in the food end up as glucose in your blood stream.
High GI foods are those that pass rapidly through your digestive system (i.e. fast-digesting) and into your blood stream. Because these types of carbs arrive in your bloodstream so quickly, they drive up blood glucose levels. This causes insulin to spike so that your body can utilize the glucose. Low GI foods are those that pass more slowly through the digestive system (i.e. slow-digesting) and gradually enter the blood stream, keeping insulin levels more consistent.
Typically, simple sugars such as table sugar (sucrose) are high GI carbs, while most complex carbs, such as sweet potatoes, are low GI carbs. However, there are many exceptions to this rule. For example, fruit is high in the sugar fructose, yet most fruits are very low GI carbs.
The reason for this is twofold. For one, most fruits are high in fiber, which slows down the digestion somewhat. Also, the sugar fructose can't be used by the muscles for fuel. It must first be converted into glucose by the liver. This process takes time to complete, keeping most fruits in the low GI category. Exceptions to this are cantaloupes, dates, and watermelon, which tend to be higher GI fruits than their counterparts.
On the other side of the coin, white potatoes are complex carbs, yet they are digested very rapidly and deliver their glucose into the bloodstream quickly, making them a high GI complex carb. The same can be said of white bread and most varieties of white rice.
At most meals, you want to focus on low GI carbs if you have any carbs at all. This will keep insulin levels low, thereby helping to maintain energy levels throughout the day, as well as burn fat. This is not just inference based on what we know about insulin's functions in the body. It has been shown in several clinical studies.
One of the most critical times to go with low GI carbs is right before workouts. For years, bodybuilders went with high GI carbs before workouts, reasoning that they needed fast energy. The problem with this thinking is that they got exactly that—fast energy—but it quickly ran out, killing their intensity before the workout was over.
In addition, they were halting fat-burning during workouts. If you consume carbs before a workout, go with 20-40 grams of low GI carbs within 30 minutes before workouts, along with 20 grams of protein powder.
Keeping generally-low insulin levels might also help your longevity outside of the gym. Research has show that when insulin levels are maintained at a low level, animals live about 50 percent longer. Although the precise mechanism for this anti-aging effect is undetermined, it is believed that the signaling that insulin causes in cells degrades them over time. By keeping insulin levels low, less insulin signaling occurs within cells, which results in healthier and longer-living cells.
You want to generally observe rule number three, but there are two times of day when high GI carbs can pay off for you. The first time is within minutes of waking—but only if your goal is to gain mass.
When you wake up, you have just endured a solid 6-8 hours of fasting. That has caused your muscle and liver glycogen (the storage form of carbs in the body) to drop. This drop in glycogen signals your body to tear down muscle tissue for fuel.
Taking in about 20-40 grams of fast-digesting carbs as soon as you get out of bed will boost insulin and quickly restock your glycogen levels and stop the muscle onslaught.
I recommend fruit in the morning. It offers other benefits such as antioxidants and other beneficial phytochemicals. Higher GI fruits may be quickest, but even low GI fruits are good.
The main reason fruits are low GI is fructose, which needs to go to the liver to be processed. But once it gets to the liver, it signals the body to stop breaking down muscle. Be sure to take those carbs with 20-40 grams of fast-digesting protein, such as whey, which will restore the muscle lost during the night.
On the other hand, if you are trying to maximize fat-loss, you may want to skip carbs altogether in the morning. Yes, you are waking in a catabolic state, but you are also burning fat due to the lower glycogen levels. Getting in a protein shake will help stop some of the muscle breakdown without halting too much of the fat burning.
No matter if your goal is gaining mass or losing fat, the other appropriate time to take in high GI or fast-digesting carbs is within 30 minutes after workouts. Here, you'll want to shoot for about 30-80 grams of those carbs along with 40 grams of protein powder. At this time, the high GI carbs will spike your insulin, which will drive those carbs and amino acids for the protein, as well as creatine (assuming you take creatine) into your muscles.
The fast carbs are critical for quickly restocking the muscle glycogen used during the workout. The amino acids will boost muscle growth, as well as further boost insulin. And the creatine, well, you should know by now that it will boost muscle growth. In addition, the insulin signals the muscle to kickstart muscle growth and halt muscle breakdown.
Research confirms that when you take high GI carbs along with fast-digesting protein, such as whey, after workouts, insulin levels soar even higher than when just high GI carbs are consumed. Whey protein has been suggested in a few studies to boost insulin levels as high as high GI carbs. This has caused many people to wonder if they should use whey protein between meals and before workouts because it spikes insulin so much. Will this hinder fat-loss?
Whey appears to spike insulin, due mainly to the amount of the branched-chain amino acid (BCAA) leucine it contains, but it does not appear to hinder fat loss in the long run. Studies show that supplementing with whey, or BCAAs, or even just leucine, actually aids in fat loss. This supplementation also appears to increase insulin sensitivity, a measure of how well your insulin receptors recognize insulin. High insulin sensitivity is good because it allows the muscles to take up more carbs. And because the leucine blunts hunger, you eat less in the long run.
So should you worry about whey protein spiking insulin? Not really. However, if you reach a point where you are having trouble dropping those last few pounds of fat on your stubborn areas, consider using casein protein, particularly micellar casein, which is a milk protein that does not spike insulin levels the way whey does. It's appropriate before workouts and any other time of day when you normally have whey shakes between meals.
This can help to get you the quality protein you need and still keep your insulin levels low; this helps keep you in an optimal state of fat-burning so you can encourage those trouble spots to let go of their fat. To get the best of both whey and casein, you can also combine them post-workout, something I often suggest in order to maximize muscle growth.
Some supplements can enhance or mimic insulin's effects at the muscle cells, which can help you to get the most out of your post-workout rise. Two of the most prominent of these are alpha lipoic acid (ALA), and Cinnulin-PF.
ALA is a potent antioxidant that enhances insulin's actions at the muscle cell. Cinnulin-PF is a trademarked water-soluble cinnamon extract whose active ingredient, hydroxychalcone, mimics the effects of insulin at the muscle cells.
If you're trying to maximize insulin's influence on muscle gain, consider stacking 300-500 mg of ALA and/or 100-250 mg of Cinnulin-PF with your post-workout carbs and protein. This could enhance insulin's actions, potentially leading to better recovery and growth after workouts.
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I love your articles Jim but they always leave me with more questions. I need to loose body fat. Muscle increase is secondary I put muscle on very easy but fat just doesnt want to go. I workout in morning usauly with only pre workout drink ( Assualt ) during workout I drink Amino drink ( extend, amino 1, or aminolast ) and same amino drink after workout. I just bought a carb drink glycofuse that is cyclic cluster dextrin when should I take it and would that be a high GI or low GI carb. I need help thanks
Carbs are not needed post workout the window of muscle growth is highly exagerated. Eat when you feel like it... Also Whey protein itself spikes insulin... The common goal is hitting your daily macros and micros on a daily basis is far more important then meal timing
I drop BF with very low carbs carbs :-), eat clean and train hard.
I skip the carbs (but not ketone diet), eat 1 peace of fruit with meal max., so body gets some carbs, but stick to low GI fruits. No post workout drink, except BCAA and whey (moxed with water or orange/grapefruit juice), before workout BCAA and whey, during the workout sometimes drink with fluid proteins (this proved to be great for my workouts). After workout, sometimes a date, to get something sweet :-)
1x week, carb loading day-2 meals with carbs, preferably with leg training (normal lunch before and a banana after)
I completely agree with you two, I gained the most muscle when I was only taking whey protein and creatine monohydrate after my workout, nothing else(worked out at night time). Whey protein does good job in helping you give just enough of insulin and not create insulin resistances or stop your body from producing GH, which your body normally does after an intense workout(basic knowledge if you read Dr. Mercola articles)
My friend, as most muscle you have, most fat you can burn...so consider to modify your goal a little bit in order to increase muscle mass.
I realize we're here to learn the best methods for muscle growth etc, but am I the only person that's concerned with casein protein or milk is known to cause cancer...and that all grains even wholemeal bread/pasta and startchy carbs like potatoes all break down into sugars in our body which are also fuel for cancer. One doctor in particular I listened to said words to this effect "the only reason we call complex carbs complex is because when nerds like me write the formula up on the board it looks more complex".
Apparently our bodies don't care whether it's simple or complex carbs...it all turns into sugar eventually...it's very harmfull to our brain to have these insulin spikes and sugar (from those sources...fruit is ok) is fuel for cancer and many other health problems.
I'm still new to a lot of this stuff so I'm hoping someone can prove me wrong because it goes against a lot of what's said on any bodybuilding nutrition site.
Brother, the only fuel source your brain uses is glucose, IE sugar. Glucose does not cause cancer, and complex carbs do break down into glucose but more slowly than simple carbs which are usually mono or disaccharides and are quickly absorbed leading to large insulin spikes.
If you have cancer, low carb diets have definitely been studied and shown to decrease tumor growth (in mice at least) being that the only fuel source metastatic cells use is glucose. This is because the cells grow too far away from the capillaries and therefore cannot utilize oxidative metabolism so they rely solely on glycolysis.
However, if you do not have cancer, there is no reason not to eat carbohydrates. Carbs don't cause cancer. Genetics, mutagens( IE smoking, chemical exposure), UV radiation, ect cause cancer.
As for what's said on bodybuilding nutrition sites, this is pretty much the cannonical approach to bodybuilding and has been for years for those in the know. In fact this is an extremely simplified version.
I don't drink, I don't smoke, I don't take drugs, and I don't spend too much time floating around radioactive material. As far as I know I don't have cancer.
Even if these things were "known" to cause it, you can bet I'd still ingest complex carbs and milk. Smoking is known to cause cancer and look at how many people still do that, at least the way we do it there are actual benefits to go with the risk.
I don't really know what you are suggesting humans should eat as an alternative, just fruit?
I went to a really interesting seminar where the speaker highlighted differences in incidence of epithelial cancers between western and Asian populations, suggesting high protein/dairy diets in the west provide the ideal metabolic state to drive a cancerous cell (a more common occurance than we think) to proliferate into full blown cancer. He speculated it to be a 'live fast die young' evolutionary mechanism where if food was abundant humans would be able to develop and reproduce more quickly- overall longevity isn't an evolutionary concern.
Interesting talk with good evidence, but yeah not gonna change the way I live or eat!
The problem with cancer cells is that they feed off of arachidonic acid which is prevalent in red meat and still about half as much so in white meat. You can basically starve cancer cells while eating a vegan diet mixed with fish for protein. It's pretty tough to build an amazing physique without adequate protein though.
This is also the problem with the milk issue (Hello China Study). That study was completely flawed in the first place, and so many people took hold of it and won't let it go. Another main problem with our milk sources is that even most organic based milk products feed off of grain, while all cows should be eating grass. Cows that eat grass produce much healthier and nutrient dense milk and are much stronger and fitter cows in their own right. Even people who eat gluten-free forget that their milk will most likely contain gluten that has been passed through a grain eating cow.
On a personal view, I eat a lot of chicken and usually beef once a day. I make sure it comes from a clean source. Is there a possibility of developing cancer? Sure. Nowadays our bodies have to detox from 1,000s of chemicals each day just from walking outside. I'm not about to worry about drinking a little bit of milk (I always drink organic anyway). Plus, all of the antioxidants I eat and take in supplemental form are off-setting a lot of free radicals I may have floating around. As long as you eat well, stay active, and try to keep your spirits up I think it's best to not dwell on the little things.
If our brain uses glucose, than why do we feed our self so much of fructose and galactose?
@Mud. You just can't beat the taste of milk coming from organic ,grassfed cows(raw for me)
Depends.... some people eat fructose because it's lower glycemic so they think that makes it better for them unfortunately. Some people don't know the difference between sugars. Some people just don't care and like the way things taste rather than how it acts in their bodies.
Everything has to be converted into glucose to be utilized by the body basically. The fructose heads straight to the liver, where in smaller doses it will be converted to glucode and burned up. People who drown stuff in agave because it's "lower glycemic" will end up storing a lot of that fructose and put on a bunch of extra unwanted fat. It also depends on what it comes from too. Eating processed fructose from a factory that added it as a sweetener is probably coming from crappy GMO corn, while fruit such as berries, bananas, apples, etc. in their original form have a huge amount of health benefits to them as long as we don't overdo it.
Show me scientific publications saying that milk causes cancer...there is no one! Come on man, be serious! There is a lot of "bro science" around that and genetic modified stuff (etc..) people don't really know and just repeat what they ear. Physicians are not a trusted source of information, papers are! Cheers mate!
YOGUI- There are several studies showing that casein causes cancerous cells to grows rapidly. it has been shown that you can practically turn off (or on) cancer growth in rates based on casein absorption. Granted, this cannot imply that it "causes" cancer.
I agree with Mudvayne though. I'm all about the raw milk from grassfed cows.
Cancer is caused by practically everything these days, but the truth is we need CARBS live. And with out them we would strive, just look at type 1 diabetics they suffer from a lack of insulin absorption and writher away. don't leave out CARBs especially if your trying to pack on muscle. its necessary.