Let’s talk about insulin
Insulin is a powerful double-edged sword for bodybuilders and fitness enthusiasts. While most people are familiar with the term, they don’t really know much about it, or why it’s critical to be strategic with it. Today is the day to remedy that and get you familiar with the basics.
Let’s start at the beginning…
What is Insulin
Insulin is a hormone that is structurally related to another one called growth hormone and is basically a protein. It is not the kind of protein that you can ingest and cause muscle growth, but the kind that signals changes in metabolism and chemistry within the body (also known as a signaling protein). It is produced by a normal functioning pancreas via specialized cells called Beta cells which are found in an area known as the Islets of Langerhans. Most cells throughout the body possess insulin receptors, which allow floating insulin to “dock” on to them and facilitate the uptake of nutrients into the cells.
Functions of Insulin
While this may be interesting, the real question is “what does it do for me”? Insulin has several functions. It:
- Controls uptake of certain macronutrients into cells, especially carbohydrates in muscle and fat cells
- Increases protein synthesis and uptake of amino acids (American Journal of Physiology, Endocrinology and Endocrinology, 1998)
- Exerts a controlling effect on the activity of various enzymes
- Promotes storage of carbohydrates such as glycogen in the liver and muscle cells
- Increases synthesis (creation) of adipose tissue (fat) via effect of causing fat cells to uptake free floating blood lipids
- Decreases the breakdown of protein (Journal of Applied Physiology, 2005)
- Increases the secretion of stomach acid (hydrochloric acid)
As you can see, the range of insulin’s effects is substantial; however, as bodybuilders, the main emphasis is on two conditions:
- Using insulin to maximize muscle growth
- Knowing when/how to control insulin to limit the storage of fat
Insulin is known to be one of the most anabolic hormones in the body because of its ability to promote muscle growth. But how does it do it? Let’s look…
How And When Insulin Is Released
Insulin is released in response to an increase in blood glucose levels, such as after consuming a high carbohydrate meal. It facilitates either the use or storage of glucose in the blood. While it is highly anabolic in nature, it does promote fat storage every time its levels are spiked, and this can result in an increase in muscle AND fat volume (not good). Since insulin can promote the storage of fat, carbohydrates, and the uptake of amino acids, the key is to know how to optimize the ‘spike’ so we build muscle without storing fat.
How To Time Your Insulin Spike For Maximum Muscle
The most crucial time to take in carbohydrates and amino acids is right after your workout. Assuming you have just worked out with enough intensity to break down muscle, the next phase involves reconstruction of all that damaged tissue. This is where spiking insulin comes into play. As we discussed, insulin is known to signal the uptake of both carbohydrates and amino acids into the muscle cells. Therefore, fast-digesting carbohydrates (such as dextrose powder) and protein shakes (such as hydrolyzed whey or whey protein isolate) immediately after the workout will effectively stop muscle breakdown, and restart growth. At this point in the anabolic window, the body increases the uptake of these vital nutrients. This allows the muscles to repair/grow in a manner that better handles the load the next time they are challenged (a process called hypertrophy).
Another time that’s prime for insulin spiking is immediately upon waking, following a 6-8 hour fast. During this period, muscle glycogen stores become depleted, with catabolism a likely outcome if amino acids and carbohydrates are not quickly supplied. The same approach is found to work here – a small dose of fast-digesting carbs and protein does the job.
Insulin and Fat Loss
Insulin and fat loss do not share a positive association since insulin release does not in any way improve the breakdown of fat (lipolysis). As we already discussed, it is shown to increase the storage of fat. So the key to leveraging insulin’s power for muscle gain, without storing fat, is the timing and content (of food) that drives the spike. We’ve already touched on timing so let’s look more closely at how to monitor the content of your food.
Glycemic Index
Outside of post-workout and post-fast times, limiting carbohydrate intake throughout the day is a very good approach. One way to accomplish this is to become intricately familiar with the glycemic index (GI) of foods. The higher the GI of a food, the faster it is digested and absorbed, and the higher the insulin spike it causes. Consuming low GI foods (that digest slowly) will cause a much weaker insulin response and is a better strategy for those who find it difficult to go with a low-carb approach to their diet. This of course assumes you DON’T want to store more fat.
While knowing the GI of foods is crucial, it is also important to know the exceptions that exist. For example, fruits possess high levels of fructose, which are known to be high GI foods. However, they also possess fiber, which significantly slows digestion. Secondly, fructose cannot be directly shuttled into fat or muscle cells; it must first be sent to the liver, turned into glucose, and then be sent back into circulation. This process does not occur very fast, but rather over a longer period of time. Let’s look at some specific examples of high and low GI foods…
What to Eat
Again, this info should be combined with what we already discussed in regards to timing.
High GI foods (to be consumed immediately after workout/upon waking):
- Dextrose
- Watermelon
- Glucose based sports drinks
- Cantaloupe
- Maltodextrin (post workout)
Low GI foods (to be consumed at all times other than post-workout and upon waking):
- Brown rice
- Whole grain pasta
- Whole grain bread
- Sweet potatoes
- Fruits (various kinds except watermelon and cantaloupe)
Don’t Forget Your Protein
If you’re trying to gain lean mass, like most readers of this blog are, then proper manipulation of insulin is a very important factor in your overall success. One thing to keep in mind is when you’re eating to spike your insulin levels, make sure you’re also consuming 30-40g of fast-acting protein and as little fat as possible. This does a couple of things.
First, by including protein you ensure your body has an adequate level of amino to repair and rebuild the muscle tissue that was damaged during high-intensity exercise.
Second, by making sure your high GI meal doesn’t include fats, you’re minimizing the amount of fat that can be stored as unsightly “body fat”.
This leads to a general rule for lean-mass development, which is:
- Eat protein at every meal
- Mix proteins and carbs or proteins and fats, but don’t mix carbs and fat, if at all possible – it only leads to fat storage.
How To Supercharge Your Insulin Spike
If you’ve followed along this far, hopefully, you understand the main point of spiking insulin immediately post-workout is to increase the uptake of essential muscle-building nutrients and put your body in an anabolic state as quickly as possible. But what if there was a way to put that process into overdrive, making it an even MORE effective process?
With the proper manipulation of insulin, it’s possible to add in a range of 10 lbs of lean mass in only 8 weeks provided you’re doing everything else you’re supposed to (diet, workout intensity, etc).
