Managing Insulin For Muscle Growth

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Gaining muscle whilst minimising fat gain - this is what the best bodybuilding programs deliver. Whilst there are many factors involved in this equation, one of the biggest players is the hormone insulin.

Insulin is a double edged sword, it can help you in your quest for muscle growth, but if it isn't managed properly, it can cause you to pile on slabs of unwanted fat too.

Insulin 101

When any food you eat has been digested, it becomes broken down into a sugar called glucose. This glucose gets released into your blood stream to be utilised by your body for energy.

Your body is always seeking a way to try and keep itself in balance, it has a natural regulatory system, and balancing glucose levels are no exception. The reason your body regulates glucose levels are because constantly high blood glucose can hammer your body causing any number of problems, not least poor wound healing, greater risk of infection, eye damage, decreased brain function and fatigue. So when your blood glucose increases, your body will try and lower it back to its normal level. This is where the insulin comes in.

Your body detects elevated glucose levels and as a response tells the pancreas to release insulin. Insulin then shuttles the glucose to parts of the body it can be stored and used as the primary source for energy.

So What's That Got to Do With Muscle Growth?

Initially insulin shuttles glucose to muscle cells. This is great for those of us looking to gain muscle as insulin in muscle cells results in an increase in protein synthesis. The growth and repair of muscles is dependent on protein synthesis.

What's more, along with stimulating protein synthesis, insulin also transports amino acids to the muscle cells. Amino acids are the building blocks from which proteins are be built from. In short... Insulin is highly anabolic (anabolism is the phase of metabolism that results in growth.)

"Great!", you're thinking, "all I need to do is weight train and eat everything in sight...pizzas, chips, greasy burgers, cream cakes, sugary soft drinks...I raise my insulin levels and gain muscle!" Sadly, it's not quite that simple. Some teenagers with super high metabolisms and high levels of naturally occurring hormones (growth hormone, testosterone etc.) might be able to get away with this, but for majority, constantly spiking insulin would pack on just as much fat as muscle, not to mention the risk of developing diabetes.

Insulin is a Double Edged Sword

After your muscle cells and liver get their fill of glucose, the next place insulin turns to dump the excess are your fat cells. If you continually eat food that causes excess glucose release, beyond filling your muscle cells, over time you will get fatter and fatter.

The other extreme is caused by not eating enough. Firstly you deprive your body of enough calories to function, so it needs to seek energy else where, initially this is your fat cells, eventually it will turn to your muscle cells too.

You will create a state of catabolism: the metabolic breakdown of body tissue in order to release energy. This takes place through a hormone called glucagon, which does the exact opposite of insulin, whereby it stimulates the breakdown of muscles by turning the tissues amino acids into glucose for energy.

Not only that, but by not eating enough, you will limit the amount of insulin that gets released into your body, which in turn will mean little or no protein synthesis, and no amino acids getting sent to your muscle cells. This means little or no anabolism. And no muscle growth.

By depriving your body of the calories it needs to function the brain assumes it's in state of starvation. So the next time you eat big meal your body will dump as much of that energy as possible into the fat stores to protect against any future periods of "starvation" that might be on the horizon. This is why so many people, when they end up trying to lose weight by eating very little, can actually end up fatter than they started. A rebound effect. And it's also the perfect recipe for ending up "skinny fat".

There are plenty of other hormones that come into play in the muscle building development, such as testosterone (learn how to increase testosterone naturally), growth hormone and leptin, but as we can see insulin is definitely one of the big boys too. But on the other hand, it's just as potent for developing a big fat belly. So what to do?

Well, luckily, we can control insulin fairly easily by being selective in what and when we eat. The primary way of doing this is by controlling the timing and the type of carbohydrates you consume.

Carbohydrates and Muscle Gain

Carbohydrates can massively influence your body's potential for muscular growth. For starters they're your body's primary choice of fuel, as they are readily converted into sugar glucose. The body stores carbs as glycogen which can be quickly broken down into glucose. Glycogen is the fuel that is necessary for intense training sessions. Without high levels of glycogen you will not be able to maintain intensity during weight training, so the stress and stimulus you need to put on your muscles, to spark growth, will be limited.

Carbs are also excellent at causing an insulin spike, so in turn carbs can trigger protein synthesis. Carbs also have a protein sparing effect. If you have low glycogen stores and aren't eating enough carbs, your body will use protein as an alternative source of energy, and when your burning protein as a fuel it means you've got no chance of growing.

And last but not least, the glucose that is stored in your muscles as glycogen, attracts water to the muscle like a magnet. Not only will your muscles look fuller and bigger when they are full of glycogen, but this process of cellular hydration may actually stimulate further muscle growth.

In short, by limiting carb intake too much you will cut short your potential for muscle development. However, if you over stimulate the insulin response, you will get fat. So how do we get adequate carbohydrate intake, enough for muscle growth, without getting fat?

Be Selective With Your Carb Sources

There are two primary forms of carbs, simple carbohydrates and complex carbohydrates. People often state that simple carbs are absorbed more quickly into the bloodstream than complex carbs, which in turn will trigger a greater insulin release, this may not be strictly true, there are other factors at play...

What's more important than if a carb is simple or complex, is the carbs' actual capacity to induce an insulin response – we want to eat carbs that are released more slowly so that they don't cause too much of an spike insulin.

Luckily for us, this area has been well researched over the years, this research has lead to the introduction of the Glycemic Index (GI). The Glycemic Index is a measure of how quickly a specific carbohydrate is converted into glucose by the body, which in turn will give us a rough idea of what sort of insulin response we should expect.

The Glycemic Index was initially created to aid diabetics in managing their blood sugar levels more effectively, but bodybuilders soon saw the advantage of the GI too.

By opting for low GI carbs over high GI carbs, you can keep insulin at levels high enough to promote a decent environment for muscle growth, but not so high as to start causing glucose to overflow into fat cells or insulin resistance.

Ideally you should stick to foods with a GI rating of 60 or less. Here are some example Glycemic Index Ratings:

The only downfall of the GI system is that it only measures the blood glucose rise. Although this is extremely useful, it does not tell us what the actual insulin response will be. Often the GI gives a fairly accurate representation of what we could expect, but some foods with a low GI actually cause a higher insulin spike than expected (milk) and some foods with high GI cause a lower insulin spike than expected (rice).

If we couple the GI with another classification system called the Insulin Index (II) then we can see the full picture. The Insulin Index is a direct measure of the insulin release caused from the digestion of food. Here are some examples of why we shouldn't rely fully on the GI:

Typically a liquid meal will be digested within 30 to 60 minutes, a whole food meal will take 2 or 3 hours to digest. So for a steady, non insulin spiking, supply of energy, whole foods win hands down. As well as food selection, food time is just as important...

Time Your Carbohydrate Consumption

One of the simplest tricks to this insulin conundrum is to time most of your carbs in and around training time. Heavy training depletes your muscle glycogen stores. Heavy training also improves insulin sensitivity, and what's more, your metabolism becomes sky high. So timing the majority of your day's carbs in meals after training means you further minimize chances of fat gain, whilst maximizing muscle growth. You could also consider using natural metabolism boosters if you had to consume a heavy carb meal later in the day, for example if you were invited out to eat.

We can take this one step further, by consuming high GI carbs directly after and during training. "What, but you said I'd get fat if I eat high GI carbs, what gives?" Let me explain...

As I've already mentioned, after training, your body is primed for carb intake due to low glycogen levels, favourable insulin sensitivity and super fast metabolism – this is even more so DIRECTLY after training. During this "window of opportunity", you can consume good amounts of high GI carbs with the chances of fat gain being virtually nil. And the benefits? The carbs will more quickly replenish your depleted glycogen stores and also trigger more protein synthesis at higher rates.

Amino acids are also key component to muscle growth, so by combining high GI carbs with quickly digested proteins you get a double bonus as the insulin spike will help shuttle the amino acids quickly and directly to your muscle cells. You get a synergistic effect.

The ideal post workout nutrients then, are maltodextrin and whey protein liquid shake. This high GI, high protein, quickly digestible drink will halt catabolism and switch gears straight into anabolism. But remember the window of opportunity slowly closes as time passes after training. So consume this drink immediately after training. Some people find sipping on this shake during training can further improve results. Also be sure to avoid eating any fats or fiber with this drink as they'll slow down the delivery of the nutrients, and limit its effect on muscle growth.

There are several commercially pre-made post work shakes available which will do this job, such as Biotest Surge and Reflex Growth Matrix. If you prefer a cheaper option you can by maltodextrin and whey separately and concoct your own shake (although it won't taste as nice).

An hour or two after training, the window of opportunity, of higher insulin sensitivity, increased metabolism and your muscles acting like magnets for amino acids, glucose and water, is still open for a couple more hours, albeit at not a quite so powerful rate...lets put it like this, the window is still half open.

With that in mind, one hour after training is an excellent opportunity to cram as many calories into your belly as possible. For this reason have you biggest solid carb meal of the day, on training days, around 1 hour after training. The meal should consist of lots of complex carbs and lots of quality protein.

By optimally timing your carbs calories round activity this way you will maximise muscle gain and limit fat.

What About Days Where I'm Not Training?

Now you understand how to time your nutrients on training days you will need to know what to do on days when you aren't training. In this case we base eating carbs around your body's needs...

When you wake in the morning insulin sensitivity is at it's most favourable, as is metabolism. As the day progresses these both become more unfavourable. For this reason, time most of your carbs (which should be low GI) earlier in the day and trail them off as evening approaches.

You're In Control

By controlling the types and time of your carbs you can ultimately have far more control over your body composition and just as importantly, health. Combine that with eating plenty of fresh fruit and vegetables, and make sure to get plenty of healthful fats, and you'll be packing on slabs of muscle without adding unwanted pounds.

By Chris Bhurrut, author and freelance writer for HealthyNewAge.com, the alternative health web site and blog.